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Primary references, normal anatomy, normal anatomy/histology-teeth
Temporomandibular joint: hypoplasia, hyperplasia, pain-dysfunction syndrome
Inflammatory: general, central giant cell granuloma, dental granuloma, hyaline ring like structures, osteomyelitis, periodontitis, peripheral giant cell granuloma
Odontogenic cysts: general, calcifying odontogenic cyst, dentigerous, eruption, gingival, glandular, keratocyst, lateral periodontal, nevoid basal cell carcinoma syndrome, paradental, periapical (radicular), residual
Fissural and other non-odontogenic cysts: general, dermoid cyst, epidermoid cyst, globulomaxillary cyst, median palatine cyst, nasolabial cyst, nasopalatine cyst, palatine cyst
Benign tumors / tumorlike conditions: odontogenic tumors-general, WHO classification, adenomatoid odontogenic, ameloblastic fibroma, aneurysmal bone cyst, calcifying epithelial odontogenic tumor, cementifying fibroma, cementoblastoma, cementoma, cherubism, desmoplastic fibroma, fibrous dysplasia, florid cemento-osseous dysplasia, giant cell tumor, gigantiform cementoma, juvenile ossifying fibroma, Langerhans cell histiocytosis, latent bone cavity, melanotic neuroectodermal tumor of infancy, meningioma, myxoma, odontogenic fibroma, odontoma, ossifying fibroma, osteoblastoma, osteoma, Paget’s disease, periapical cemental dysplasia, simple bone cyst, squamous odontogenic tumor
Malignant tumors: ameloblastic carcinoma, ameloblastic fibrosarcoma, ameloblastoma, clear cell carcinoma of salivary gland, clear cell odontogenic carcinoma, lymphoma, malignant ameloblastoma, metastases to jaw, odontogenic carcinoma, odontogenic ghost cell tumor, osteosarcoma, primary intraosseous carcinoma
American Journal of Surgical Pathology (AJSP), March 1977 to Jan 2004
Archives of Pathology and Laboratory Medicine (Archives), January 1976 to March 2004
Human Pathology, March 1970 to Feb 2004
Modern Pathology, Jan 1988 to March 2004
Rosai, J: Ackerman’s Surgical Pathology (8th Ed); Mosby-Year Book, Inc., 1996
Sternberg, S: Diagnostic Surgical Pathology (3rd Ed); Lippincott Williams & Wilkins, 1999
Journal search terms: jaw, mandible, maxilla, odontogenic, tooth, teeth
Please refer to these primary references for more detailed discussions and photographs
Contain primitive embryonic structures from early fetal development to 25 years of age
Divided into alveolar bone (supports teeth) and body, with variable thickness ranging from paper thin overlying roots of cuspid (canines) and bicuspid (premolar) teeth to thick at apex of chin
Mandible: receptor for lower teeth; consists of curved horizontal body and two perpendicular rami
Maxillae: forms upper jaw, boundaries of roof of mouth, floor and lateral wall of nose, floor of orbit; consists of zygomatic, frontal, alveolar and palatine processes
Drawings: teeth and jaws
Mandible: outer surface, inner surface, lower dental arch
Maxilla: outer surface, nasal surface, opened from exterior, hard palate
Embryology: mandible of early fetus
Normal anatomy/histology-teeth
Composed of outer enamel adjacent to dentin and inner pulp; surrounded by periodontal membrane and attached to bone by cementum
Development: (1) primitive oral cavity (dental lamina, derived from ectoderm) invaginates, acquires a bell shape, and ameloblasts develop along inner (concave) surface; called “enamel organ” at this stage; (2) dental papilla, derived from mesoderm, forms within “enamel organ”, is loose stellate reticulum; its outer layer matures to become odontoblasts; (3) dental sac or follicle forms from outer layer of dental papillae / odontoblasts, which form periodontium, a fibrous sheath enveloping the tooth; (4) inner layer of dental sac become cementoblasts and deposit cement over newly formed dentin, and outer layer of dental sac becomes osteoblasts and produces alveolar bone
Three phases of activity: (1) initiation of entire deciduous dentition (first set of teeth) during second month of gestation (above); (2) initiation of permanent dentition (second set of teeth) and extension of dental lamina distal to dental organ of second deciduous molar; (3) after 5-6 years of activity, dental lamina breaks up into epithelial rests or islands that may develop into odontogenic cysts or tumors
Teeth from medial to lateral: incisors, canines (cuspids), premolars (bicuspids), molars
Ameloblasts (adamantoblasts): secrete enamel matrix
Cementicles: rounded, strongly basophilic structures normally within periodontal ligament
Cementum: similar to bone, cellular or acellular, intensely basophilic; also present in other parts of skeletal system
Dental lamina: epithelium with potential to develop teeth; derived from primitive oral epithelium along free margin of arches of jaws
Dental pulp: hypocellular, myxoid; resembles myxoma but is compact and has peripheral odontoblasts
Dentin: radially striated due to numerous minute canals (dentinal tubules) containing cytoplasmic processes from odontoblasts; resembles osteoid if tubules / canals are absent
Enamel: thin rods or prisms separated on cross section by concentric lines of Retzius
Nests of Serres: nests of ameloblasts, cementoblasts and odontoblasts located in alveolar mucosa, due to breakup of dental lamina
Odontoblasts: form dentinal matrix
Rests of Malassez: nests of ameloblasts, cementoblasts and odontoblasts embedded within periodontium
Drawings: histology of growing tooth, permanent teeth, tooth, tooth in situ, tooth of early fetus
Images: developing tooth (odontoblast and periodontal membrane)
Temporomandibular joint
Unilateral or bilateral involvement of mandibular condyle
Associated with facial asymmetry and abnormal function, anomalies of ear, temporal bone and macrostomia (exaggerated width of mouth)
May be due to mandibular fracture or trauma during growth
Usually an isolated finding in adults with unilateral facial enlargement
Also associated with hemihypertrophy
May be related to synovial chondromatosis or osteochondromatosis
Gross: large condyle
Micro: thick and irregular hyaline or fibrohyaline cartilage on articular surface of condyle; may be markedly cellular
DD: chondrosarcoma (if cellular)
Symptoms: limitation of jaw movement, pain, discomfort, tenderness, joint clicking
Usually nonspecific pathologic features
Inflammatory lesions
Usually due to untreated dental caries, causing inflammation of pulpal or soft tissue portions of teeth, then inflammation of cancellous bone and connective tissue surrounding dental root apices
Also called giant cell reparative granuloma
Central if intraosseous; peripheral if extraosseous
May be due to recurrent slow, minute hemorrhages; often associated with trauma
Children and young adults, usually females
Lesion appears to be unique to jaw; usually anterior mandible
Xray: radiolucent, multilocular lesion, may have resorption / movement of teeth and penetration of jaw cortex
Treatment: excision, thorough curettage
May recur
Gross: cystic bone lesion
Micro: numerous osteoclast-like giant cells near hemorrhagic areas, cellular vascular and fibrous stroma, new bone formation at edge of lesion; frequent mitotic figures; no necrosis
Micro images: osteoclast-like giant cells in cellular stroma #1, #2, #3
Micro images (Mod Path subscribers): low power, osteoclast-like giant cells
Positive stains: CD68 (giant cells)
EM: fibroblasts, myofibroblasts, histiocytes
DD: giant cell tumor, hyperparathyroidism, aneurysmal bone cyst
Also called localized osteitis
May undergo cystic degeneration forming radicular cyst (periapical cyst) [below]
Often found on dental Xrays
Gross: 1.5 cm or less
Micro: histiocytes and other chronic inflammatory cells surrounded by dense fibrous tissue
Also called pulse granuloma (pulse is edible seed of legumes)
Associated with chronic periostitis
May be a degenerative change in vessel walls from vasculitis or a reaction to legume parenchymatous cells at various stages of digestion Micro: hyaline ring like structures, some containing granular necrotic material, surround giant cells, vessels and collagen, and are themselves surrounded by chronic inflammatory cells
Usually an extension of dental or periodontal infection
Late finding is atrophy of covering mucosa, dull and devitalized exposed bone
Usually due to Staphylococcus aureus; occasionally anaerobes
Xray: irregular, ill-defined, radiolucent lesions; may be subtle
Gross: sequestrum (dead bone)
Micro: abscess cavities, resorptive scalloping of margins of dead bone within large portion of maxilla or mandible
Chronic osteomyelitis
Usually low grade, asymptomatic
Micro: marked new bone formation (irregular size and shape) with osteoblasts and osteoclasts mixed with mature lamellar bone, often scant inflammatory cells
DD: fibro-osseous lesions (ossifying fibroma, fibrous dysplasia)
Recurrent and continuous gingivitis that affects alveolar bone
Causes bone destruction and pockets around teeth > 3 mm in depth
Plaque within pockets serves as nidus for mineralization (dental calculus), causing progressive disease until gingival scarring and bony erosion lead to loss of teeth
Treatment: scaling and cleaning of root surfaces to remove focal irritants, surgery, brushing and flossing
Peripheral giant cell granuloma
Also called giant cell epulis
Resembles pyogenic granuloma, but may erode alveolar bone or involve periodontal membrane
Usually women, mean age 30 years, although may involve children or elderly patients without teeth
May be due to trauma, local irritation or chronic infection
Recurs if not completely excised
Treatment: excision with curettage of base of lesion extending into adjacent periodontal membrane
Gross: inflammatory lesion up to 1.5 cm that protrudes from gingiva at site of chronic inflammation; covered by gingival mucosa or ulcerated
Micro: nonencapsulated aggregates of foreign body giant cells and fibroangiomatous stroma with hemorrhage, hemosiderin, acute and chronic inflammatory cells; alveolar bone often expanded in edentulous patients leading to superficial bone loss with peripheral cuffing
DD: giant cell granulomas of maxilla/mandible, giant cell “brown tumors” of hyperparathyroidism
Odontogenic cysts
Derived from odontogenic epithelium (ameloblasts, cementoblasts, odontoblasts) around impacted or nonerupted teeth, or from epithelial rests or remnants of dental lamina
Rarely associated with carcinoma, usually squamous cell carcinoma; also mucoepidermoid carcinoma
References: Mod Path 2002;15:331
Also called Gorlin cyst
A developmental cyst that presents as painless enlargement of maxilla or mandible, usually in canine-premolar region
Mean age 31 years, range 12-72 years, female predominance in some studies
Most appear to be non-neoplastic
May be associated with odontoma and ameloblastic fibrodontoma
Proposed classification differentiates this developmental cyst from a benign neoplasm (odontogenic ghost cell tumor or other odontogenic tumors with calcifying odontogenic cyst features) and odontogenic carcinoma, AJSP 2003;27:372
Xray: unicystic radiolucency with focal opacification
Treatment: complete excision conserving dental structures; usually does not recur
Gross: unicystic, often 2 cm or less; no solid areas
Micro: well defined layer of palisading basal cells, loosely arranged suprabasal epithelial cells resembling stellate reticulum; epithelium also contains pale, eosinophilic ghost cells that may keratinize or calcify; dentin may be laid down next to basal cells; variable foreign body reaction
Note: ghost cells also present in ameloblastoma and odontoma
Micro images (Mod Path subscribers): ghost cell keratinization, dystrophic calcification and palisading basal cells
DD: odontoma, cementoma, odontogenic keratocyst, craniopharyngioma, sweat gland tumor
Surrounds crown of nonerupted permanent tooth in young adults
Common; found in 1% with complete dental Xrays
Due to fluid accumulating between ameloblasts (epithelium that produces the crown) and nonerupted tooth
Associated with missing tooth, usually permanent third molars and maxillary cuspids
May be destructive, causing bone expansion and teeth displacement
Don’t recur; recurrence suggests incomplete excision, keratocyst or other cystlike condition or ameloblastoma
Rarely transforms to ameloblastoma
Xray: unilocular radiolucency
Treatment: enucleation with tooth of origin
Micro: stratified squamous epithelium lining without keratinization continuous with ameloblasts of crown; also myxomatous fibrous tissue, dental organ epithelium; variable hyperplasia, calcification, metaplasia, dysplasia, neoplasia; no inflammation unless secondary infection
Type of dentigerous cyst affecting erupting deciduous teeth
Children (11% during eruption of incisors and 30% of infants during eruption of deciduous cuspids and molars)
Treatment: removal of cyst overlying tooth
Gross: blue-red dome shaped lesion of alveolar ridge overlying erupting tooth
Micro: inflamed and hemorrhagic cyst wall lined by thin, nonkeratinizing stratified squamous epithelium
Newborn infants, rarely adults
Also called Epstein’s pearls or Bohn’s nodules
Due to cystic degeneration of dental lamina
Usually disappear in weeks
Treatment: simple excision or wait
Gross: white nodules in gingiva
Micro: squamous or cuboidal lined inclusion cysts
Also called sialo-odontogenic cyst
Uncommon developmental cyst
More likely in men, mean age 50 years
Usually mandible
May recur after enucleation
Gross: multilocular
Micro: nonkeratinized stratified squamous epithelium mixed with cystlike spaces lined by cuboidal and ciliated epithelium, focal thickenings have mucous cells in pseudoglandular pattern
Micro images (Mod Path subscribers): focal thickenings with pseudoglandular formation
Positive stains: PAS+ diastase resistant pools in cystlike spaces
DD: mucoepidermoid carcinoma, adenomatoid odontogenic tumor, dentigerous cysts
10% of jaw cysts
Mean age 30-40 years
May be neoplastic due to frequent loss of heterozygosity of p16, p53, PTCH and MCC, Archives 2004;128:313
90% solitary; multiple tumors associated with nevoid basal cell carcinoma syndrome
May be destructive, 10-60% recur; more likely to recur if multiple, whether part of a syndrome or not
Sites: any position in jaw, may be superimposed over tooth root apices or adjacent to crowns of impacted teeth
Xray: multilocular or unilocular radiolucency in posterior mandible or maxilla; less often in anterior maxilla
Xray image (Mod Path subscribers): large mandibular lesion
Treatment: complete excision
May recur, invade bone or undergo malignant transformation into squamous cell carcinoma
Gross: contains cheesy keratinized debris, wrinkly white inner cyst lining
Micro: mildly verrucous, 6-10 cell thick, keratinizing, stratified squamous epithelium; prominent palisading basal cell layer, fibrous connective wall often is separated from epithelium; also daughter cysts with undulating tortuous projections of cyst; cyst may become secondarily inflamed
Orthokeratinized variant: orthokeratosis (anuclear keratin), granular layer and poorly organized basal layer; not syndrome associated, less aggressive behavior
Micro images: classic features, budding, daughter cyst, 1-multiple mandibular cysts, 2-low power, 3-calcification of falx cerebri (arrow), 4-plamar pit
Micro images (Mod Path subscribers): parakeratinized epithelium with basal cell palisading, orthokeratinized variant with granular cell layer
Rare developmental odontogenic cyst of alveolar bone at roots of mandibular cuspids or bicuspids
May be due to cystic degeneration of local epithelial rests
Treatment: surgical excision
Micro: very thin epithelium (1-2 layers)
Nevoid basal cell carcinoma syndrome
Also called Gorlin-Goltz syndrome, basal cell nevus syndrome
Autosomal dominant, usually high penetrance but variable expressivity, incidence 1 per 60,000 people
Features: multiple odontogenic keratocysts, multiple basal cell carcinomas early in life (in 90%), congenital skeletal anomalies (bifid rib), dyskeratotic pitting of hands and feet (palmoplantar pits in 50-75% of adults, usually develop in teenagers, pits due to diminished stratum corneum), ectopic calcifications of falx cerebri (80-90% vs. 3-6% of normals); also bilateral calcified ovarian fibromas and medulloblastoma
Due to mutations in PTCH (PATCHED) tumor suppressor gene at 9q22.3, which allows unregulated cell division (mutation also present in keratocysts)
Case report of 24 year old man with multiple odontogenic keratocysts and cutaneous lesions, Archives 2003;127:e165
Usually men
Associated with crown of tooth
Develops on buccal distal or mesial (“toward middle of front of jaw along curve of dental arch”) aspect of partially erupted mandibular third molar
Does not displace teeth
Treatment: enucleation
Gross: 1-2 cm cyst, attached to cemento-enamel junction and coronal (towards crown) portion of root
Micro: inflammatory cyst, otherwise similar to periapical cyst
Most common odontogenic cyst
Due to severe pulpal inflammation or pulp death, secondary to trauma or dental caries
Usually ages 20-39 years
Cyst lining derived from epithelial rests of Malassez left after tooth development
Usually maxillary incisors and mandibular molars
Incidental finding
Xray: radiolucency with prominent radiopaque margin of focal sclerosing osteomyelitis or osteitis
Treatment: enucleation
Gross: 1 cm or less, round or flask-shaped; may be attached to apex of extracted tooth
Micro: lined by hyperplastic squamous epithelium with diffuse inflammatory cells, variable keratinization and ulceration; may have goblet cells or hyaline bodies (Rushton bodies)
Rushton bodies: may be product of cyst epithelium resembling dental cuticle
Periapical cyst after extraction of involved tooth
Fissural and other non odontogenic cysts
Fissural cysts occur at junction of developing structures in head and neck
Due to enclavement of epithelial tissue (“trapped in other structures”) and delay in development of growth centers
Not odontogenic origin
Medial: median mandibular, median palatal, nasopalatine cysts
Lateral: globulomaxillary, nasolabial cysts
Micro: squamous lining with cutaneous adnexae
Micro: squamous lining without cutaneous adnexae
Disputed as a specific entity
Considered an obsolete concept by some (J Oral Path 1985;14:1, J Oral Path Med 1989;18:125) but not all (Oral Surg Oral Med Oral Path 1993;76:182)
Arise in same area as nasolabial cysts but in alveolar bone at union of globular process and maxillary process
Most (or all) are considered of odontogenic origin
Xray: pear shaped radiolucency between maxillary lateral incisor and cuspid; causes divergence of tooth roots
Treatment: enucleation
Micro: lined by stratified squamous or respiratory type epithelium
Posterior to nasopalatine duct cyst
Due to enclavement of epithelium during fusion of right and left maxillary palatine processes
May be intraosseous or within soft tissues of palatine papilla
Xray: well circumscribed, midline radiolucency, usually in molar region
Treatment: enucleation
Micro: lined by stratified squamous epithelium or respiratory mucosa
Also called nasoalveolar cyst, Klestadt cyst
Associated with fusion of maxillary and globular processes, may develop from caudal end of nasolacrimal rod or duct
Arises in soft tissue of upper lip or lateral aspect of nose, may be bilateral
More common in blacks and women
Often becomes infected, obliterates nasolabial fold
Treatment: enucleation
Micro: lined by stratified squamous or respiratory epithelium
Due to enclavement of vestigial oronasal cysts
Usually ages 30-59 years
May develop entirely within bone, within incisive papilla of anterior palatal gingiva or within bone and soft tissue
Micro: lined by stratified squamous or respiratory epithelium; prominent neurovascular bundle within connective tissue wall; variable cartilage
Called Epstein’s pearls (also gingival cysts)
At junction of hard and soft palate in newborns
Micro: squamous or cuboidal lined inclusion cysts
Benign tumors / tumorlike conditions
Uncommon
Arise from odontogenic epithelium
MALIGNANT TUMORS
1. Odontogenic carcinomas
- Metastasizing (malignant) ameloblastoma
- Ameloblastic carcinoma (primary and secondary type)
- Primary intraosseous squamous cell carcinoma (solid, derived from KCOT and derived from odontogenic cysts)
- Clear cell odontogenic carcinoma
- Ghost cell odontogenic carcinoma
2. Odontogenic sarcoma
- Ameloblastic fibrosarcoma
- Ameloblastic fibrodentino-and fibro-odontosarcoma
BENIGN TUMORS
Odontogenic epithelium with mature, fibrous stroma without odontogenic ectomesenchyme
- Ameloblastoma, solid/multicystic type
- Ameloblastoma, extraosseous/peripheral type
- Ameloblastoma, desmoplastic type
- Ameloblastoma, unicystic type
- Squamous odontogenic tumor
- Calcifying epithelial odontogenic tumor
- Adenomatoid odontogenic tumor
- Keratocystic Odontogenic tumor *
Odontogenic epithelium with odontogenic ectomesenchyme, with or without hard tissue formation
- Ameloblastic fibroma
- Ameloblastic fibrodentinoma
- Ameloblastic fibro-odontoma
- Odontoma, complex and compound
- Odontoameloblastoma
- Calcifying cystic odontogenic tumor **
- Dentinogenic ghost cell tumor
Mesenchyme and/or odontogenic ectomesenchyme with or without epithelium
- Odontogenic fibroma
- Odontogenic myxoma / myxofibroma
- Cementoblastoma
Bone related lesions
- Ossifying fibroma
- Fibrous dysplasia
- Osseous dysplasia
- Central giant cell lesion (granuloma)
- Cherubism
- Aneurysmal bone cyst
- Simple bone cyst
OTHER TUMORS
- Melanotic neuroectodermal tumor of infancy
* formerly known as OKC (odontogenic keratocyst)
** formerly known as Gorlin cyst
Also called adenoameloblastoma
Relatively uncommon
70% in teens, remainder from 5 to 50 years, more common in females
Associated with unerupted canine tooth
Slow growing, few/no symptoms
Sites: incisor-cuspid area of maxilla
Xray: well defined unilocular lesion surrounding crown of unerupted or impacted tooth; may be cystic or expansive but not invasive
Treatment: enucleation; does not recur
Case reports: 28 year old man with tumor and impacted tooth, Archives 2003;127:e173
Gross: rounded, well defined fibrous capsule, cystic with focal solid areas; crown of tooth usually projects into cystic cavity
Micro: well circumscribed, central proliferation of ductlike epithelium surrounding small foci of calcification; epithelium may have rosettes, trabecular or cribriform patterns; columnar type cells with basal nuclei and clear cytoplasm may resemble pre-ameloblasts; eosinophilic fibrillar material is present between tumor cells and within ductlike structures; rarely melanin deposition
Micro images: 1-solitary cyst-like lesion, 2-4 ductlike spaces and solid nodules
EM: glandular differentiation
DD: odontogenic cyst, dentigerous cyst
Rare
Usually age 20 or less
Benign, rarely recurs
Xray: variable radiolucent-radiopaque appearance
Treatment: simple curettage
Gross: usually solid
Micro: small islands and cords of markedly attenuated ameloblastic epithelium two cells thick within dense collagenous stroma that is often immature; occasional dentin or cementum production and stellate reticulum; also granular cell variant
DD: ameloblastoma (no connective tissue stroma, has dentin and enamel)
May massively expand the mandible
Young females
Micro: numerous giant cells in connective tissue that lines large sinusoidal spaces
DD: central giant cell granuloma
Calcifying epithelial odontogenic tumor
Also called Pindborg tumor
Rare
Ages 30-49 years
May also occur within gingiva (peripheral tumor)
May be invasive and recur locally, but less aggressive than ameloblastoma
Case reports: metastasis to regional lymph node (J Oral Path 1984;13:310), characterization of amyloid as degenerative keratin filaments (Archives 2000;124:872)
Sites: premolar mandible, often associated with embedded tooth
Xray: resembles dentigerous cyst with occasional small radiopacities within large radiolucent area
Treatment: less aggressive than ameloblastoma
Micro: sheets of polyhedral, eosinophilic squamous epithelial cells with focal psammoma bodies; variable markedly pleomorphic cells with 2-3 nuclei; amyloid bodies (containing degenerated keratin filaments); often scanty stroma, although epithelium / stromal ratio is variable between tumors; clear cell variant has clear vacuolated cytoplasm
Micro images: squamous epithelial cells with calcifications and eosinophilic (amyloid) bodies, keratin
Micro images (Mod Path subscribers): atypical epithelial cells, calcification and amyloid bodies
Positive stains: keratin, Congo red (amyloid bodies)
EM images: fibrillary mesh of amyloid, bundles of tonofilaments
Mandibular neoplasm of men and women ages 40+ years
May be variant of fibrous dysplasia
Xray: well circumscribed, initially well defined radiolucency, later has central calcifications with radiolucent peripheral rim
Treatment: excision
Micro: cellular fibrous connective tissue with multiple round/oval psammoma-like calcifications resembling cement which may coalesce to form lobulated masses
Cemento-ossifying fibroma: same tumor with trabeculae; some consider it to be related to fibrous dysplasia, AJSP 1995;19:775
Also called true cementoma, benign osteoblastoma
Men and women less than 25 years old
Benign, may stop growing as a heavily calcified jaw nodule, may recur if excised
Xray: dense homogenous mass continuous with tooth root
Gross: large mass of cementum on root of mandibular premolar or molar; tooth viable
Micro: large cementicles (globules) fused to form a mass within proliferative fibrovascular stroma; trabeculae lined by plump osteoblasts
Generic term for periapical cemental dysplasia, central cementifying fibroma, cementoblastoma (true cementoma) or gigantiform cementoma
Hereditary and intraosseous fibrous swellings of jaws
Autosomal dominant, bilateral involvement of mandible and maxilla in young individuals
Treatment: surgery may not be indicated
Micro: similar to central giant cell granuloma; also more delicate fibrovascular stroma without bone formation
Rare, mean 23 years, range 1-75 years
Intraosseous component of soft tissue fibromatosis
May be due to local trauma; may be part of Gardner’s syndrome
Benign, but up to 35% recur, does not metastasize
Treatment: wide local excision
Case reports: 3 year old boy with mandibular lesion, Archives 2002;126:107
Gross: firm, rubbery, white, nonencapsulated, fibrous-appearing lesion
Micro: poorly demarcated lesion with interlacing or fascicular pattern of mature fibrous tissue composed of small fibroblasts with no/minimal mitotic activity and abundant collagenous stroma; no osteoid, no epithelial rests, rare multinucleated giant cells
Micro images: 1-CT scan of mandibular lesion, 2-spindled lesion with fibromyxoid stroma, 3-high power
Micro images (Mod Path subscribers): figure B-evenly distributed fibroblasts in collagenous stroma
Positive stains: vimentin
Negative stains: S100, muscle markers, keratin
DD: fibrosarcoma, aneurysmal bone cyst, chondromyxoid fibroma, central ossifying fibroma, monostotic fibrous dysplasia, low grade osteosarcoma
Fibrous dysplasia and variants
Called craniofacial form of fibrous dysplasia if confined to jaw
Monostotic, polyostotic or associated with McCune-Albright syndrome
May be congenital or hereditary (but differs from cherubism)
Starts in childhood, usually diagnosed by age 20 years
Symptoms: unilateral painless swelling of mandible or maxilla in men/women ages 25-35 years
No treatment since growth is self-limited and responsive to pubertal hormonal changes
Surgical recontouring performed if facial deformity, although may regrow in 25%
Xray: ill-defined margins, diffusely radiopaque with ground glass image
Micro: uniformly distributed C-shaped or Chinese figure-like trabeculae of woven/immature bone within proliferating fibroblastic and vascularized stroma; usually no osteoblastic rimming and no/rare osteoclasts
Micro images (Mod Path subscribers): curved bony trabeculae in fibrous stroma
McCune-Albright syndrome
Due to somatic mutation of c-fos oncogene that causes activation of cAMP pathway
Polyostotic fibrous dysplasia, cafe-au-lait skin pigmentation (large, dark lesions with serpiginous [“coast of Maine”] borders in chest, neck, back), almost exclusively in women
Also endocrine abnormalities (precocious puberty, hyperthyroidism, pituitary adenomas that secrete growth hormone primary adrenal hyperplasia)
Florid cemento-osseous dysplasia
Exuberant form of periapical cemento-osseous dysplasia
May affect entire mandible
Associated with traumatic bone cysts
No treatment required unless secondary infection
Xray images (Mod Path subscribers): involvement of entire mandible
Micro: benign fibro-osseous lesion with mature and immature bony islands and trabeculae in bland connective tissue; scant inflammatory cells; may become secondarily inflamed with superimposed chronic osteomyelitis
Micro images (Mod Path subscribers): mature and immature bone in fibrous stroma
Very rare in jaw
Associated with Paget’s disease
Should rule out other giant cell tumors
Micro: very large giant cells with large numbers of nuclei that are centrally aggregated; giant cells are diffusely distributed; high stromal cellularity, necrosis
DD: central giant cell granuloma, aneurysmal bone cyst, brown tumor of hyperparathyroidism (elevated serum calcium and parathormone), cherubism (similar histology, children, autosomal dominant, bilateral jaw involvement)
Autosomal dominant
Usually young black women
Susceptible to infection and sequestration
Diffuse deposition of acellular cementum on tooth roots in all quadrants of jaw
Also called juvenile active (aggressive) ossifying fibroma
Rare, rapidly growing benign but aggressive neoplasm of young patients 5-15 years old, more common in males
Commonly associated with proptosis (forward displacement of eyeball)
Fibro-osseous lesion, some consider part of the spectrum of fibrous dysplasia
Case reports: 10 year old with maxillary mass (Archives 2003;127:e359), 15 year old boy with rapidly growing mandibular mass (Archives 2001;125:1117)
Treatment: curettage or excision for small lesions; wide excision for large or rapidly growing lesions
30-58% recur, but no malignant transformation
Gross: discrete mass well demarcated from surrounding bone, tan-white-yellow, homogenous, rubbery cut surface, firm to gritty
Gross images: large tan mass
Micro: markedly cellular fibrous and myxoid stroma; irregularly distributed trabecular and psammomatoid patterns; prominent osteoblastic rimming of trabeculae; occasional osteoclast-like giant cells; minimal atypia, no/minimal mitotic figures
Micro images: 1-maxillary lesion, 2-partially encapsulated mass, 3-cellular spindle cell stroma with fibromyxoid background, 4-bland nuclei, 1-Xray, 2-fibroblastic stroma with irregularly distributed trabecular bone, cellular fibrous stroma with irregularly distributed trabeculae and psammoma bodies #1, #2, #3
Often occurs in jaw, usually mandible
Causes localized, ragged zone of destruction
Open cavity below and behind inferior dental canal near angle of mandible
Often contains salivary gland tissue
Melanotic neuroectodermal tumor of infancy
Also called melanotic progonoma, melanotic neuroectodermal tumor, retinal anlage tumor
Rare neuroectodermal tumor, usually in children under 1 year old
Appears to recapitulate the retina at 5 weeks of gestation
Usually maxilla; also mandible, skull, long bones, epididymis, mediastinum, soft tissue of extremities
Usually benign, may recur, rarely distant metastases
Laboratory: produces VMA
Micro: irregular islands of small neuroblastic cells with scant or fibrillar cytoplasm adjacent to larger cells with abundant eosinophilic cytoplasm, round/oval nuclei, prominent nuclei, containing melanin granules; surrounded by cellular fibrous stroma, growing around bony trabeculae; no atypia, no squamous differentiation, no/rare necrosis, no mitotic figures
Micro images: biphasic population #1, #2, #3, melanin pigment
Positive stains: large cells - keratin, HMB45, vimentin, Leu7/CD57; variable EMA, neuron-specific enolase, synaptophysin, GFAP, S100; small cells - neuron-specific enolase, CD56, variable Leu7/CD57
Negative stains: CEA
EM: melanosomes, neurosecretory granules, cytoplasmic processes
DD: neuroblastoma, Ewings/PNET, rhabdomyosarcoma, melanoma
References: AJSP 1993;17:566, AJSP 1991;15:233
Rarely occurs in mandible
Due to ectopic nests of arachnoid or perineural cells
Also called odontogenic myxoma since apparently derived from dental papilla
May be related to malformed or missing teeth
Usually teenagers or young adults
Benign but locally destructive; slow growing, may produce obvious facial deformity, may recur and persist up to 30 years, even with aggressive treatment
Xray: cystlike lesion with soap bubble appearance
Gross images: well circumscribed myxoid tan-yellow tumor
Micro: loose bland stellate cells with long, branching cytoplasmic processes; occasional rests of Malassez; called myxofibroma or fibromyxoma if prominent collagen; frequent residual bony trabeculae present; no/minimal odontogenic epithelium
Micro images (Mod Path subscribers): left-myxoma, right-follicular sac with adjacent enamel, bland stellate cells in myxoid stroma #1, #2, #3
Positive stains: vimentin
Negative stains: S100
DD: normal dental pulp (peripheral columnar shaped odontoblasts), follicular sac (normal tissue around crowns of unerupted teeth)
Uncommon
Neoplasm derived from periodontal ligament or pulp-related fibroblasts
Peripheral or central
Usually maxilla
Xray: central tumors are expansile multilocular radiolucencies
Treatment: excision, usually does not recur
Gross: well circumscribed gingival mass
Micro: fibrous tissue containing fibroblasts with occasional islands of odontogenic epithelium or calcification; variable multinucleated giant cells, granular cells, clear cells; also myxoid component
Micro images (Mod Path subscribers): figure A-fibrous tissue with odontogenic rests
Most common odontogenic tumor, probably a hamartoma
Produce calcified parts of teeth
Found between the roots of teeth in alveolar ridge
Treatment: excision
Micro: arises from epithelium, shows extensive deposits of enamel and dentin (has tubular appearance) forming small, irregular teeth or an irregular mass of tooth tissues (cementum, dentin, enamel)
Ameloblastic odontoma
Enamel, dentin and prominent epithelial component resembling ameloblastoma
May be predominantly cystic
Benign, but may recur locally after excision
Complex odontoma
Poorly differentiated with dentin, enamel and cementum production but not enough to identify an actual tooth
Usually mandibular molar areas of women
May be large, but benign
Often incidental finding
Compound odontoma
Masses of small misshapen teeth (3-2000), more differentiated than complex odontoma
Benign
Anterior jaw, usually maxilla
Also called fibrous osteoma
Ages 20-39 years, more often women
Benign bone tumor similar to cementifying fibroma and cemento-ossifying fibroma
Slow growing lesion of mandibular body and ramus
Does require treatment (probably excision), unlike most fibrous dysplasia lesions
Gross: well circumscribed
Micro: well demarcated from bone; trabeculae or spherical islands of bone uniform throughout the lesion, prominent osteoblastic rimming, scant osteoclasts, variable stromal cellularity
Micro images (Mod Path subscribers): cellular stroma with trabeculae or spherical islands of bone
DD: juvenile ossifying fibroma (more aggressive clinical behavior, more cellular stroma), cemento-ossifying fibromas (predominantly spherical/oval islands of bone, similar behavior), fibrous dysplasia (irregular distribution of bony trabeculae, uniform stromal cellularity)
Case report: large cell, epithelioid, aneurysmal variant in 14 year old girl, simulating telangiectatic osteosarcoma (Hum Path 1999;30:1254)
Present in 80% with Gardner’s syndrome
Common in frontal and ethmoid sinuses of mandible
Either sole site (monostotic form) or as expression of generalized process
Associated with osteosarcoma and giant cell tumor
Also called cemento-osseous dysplasia, cementoma, periapical osteofibrosis
Most frequent form of cementoma or fibro-osseous lesion of jaw, 0.3% of adults
Reactive lesion, may be due to reaction of bone to local low grade or chronic injury
Affects black women ages 20+, rarely men
Involves apical area of vital anterior mandibular teeth, often multiple incisors
Asymptomatic, no treatment required unless complicated by superimposed osteomyelitis
Case report in 70 year old woman with painful mandibular enlargement, Archives 2003;127:e427
Gross: tenaciously adherent to surrounding bone, so received as small, hemorrhagic, gritty fragments
Micro: early osteolytic stage has cellular, fibrous connective tissue with numerous irregularly dilated blood vessels and hemorrhage, contains small amounts of irregular women bone and rounded droplets of cementum-like material; bony trabeculae are thick, curvilinear, relatively acellular and anastomosing, resembling “ginger roots”; blends into surrounding medullary bone and cortex; mature stage has excessive calcification (cementum) causing sclerosing masses, often with prominent resting and reversal lines, fibrous stroma is loosely arranged and less cellar, with less prominent vessels and hemorrhage; intermediate stage has osteoblastic rimming
Micro images: 1-radiopaque lesion, 2-woven bone without osteoblastic rimming, 3-sclerotic masses, 4-mildly inflamed stroma
DD: fibrous dysplasia (better defined trabeculae), osteomyelitis
Young patients
50% have history of trauma
May be jaw counterpart of solitary bone cyst
Xray: sharply outlined radiolucent mass with thin shell of remaining bone
Treatment: thorough curettage; rarely recurs
Gross: body or symphyseal area of mandible, large, intraosseous lesion; usually solitary
Micro: lined by fibrovascular tissue, no epithelial lining; occasional hemosiderin-laden macrophages and osteoclast-like giant cells
DD: aneurysmal bone cyst (associated with benign fibro-osseous lesions), latent bone cavity
Uncommon
Most common in 20’s, but occurs in all ages, 2/3 male
Usually in anterior maxilla or posterior mandible in soft tissue or bone; 25% are multiple lesions
Arises from rests of Malassez in periodontal ligament
Low probability of recurrence, no malignant transformation reported
Xray: well circumscribed, semicircular radiolucency, sclerotic border, near teeth roots
Case reports: 30 year old African American woman with incidental finding, Archives 2001;125:297
Treatment: excision with extraction of involved teeth or en bloc resection
Micro: anastomosing islands of benign, stratified squamous epithelium within fibrous stroma, often well defined nests with clear cells; may contain keratin or psammoma bodies; often epithelial vacuolization and microcysts; no atypia, no mitotic figures, no inflammation, no peripheral palisading
Micro images: radiolucent lesion between roots of teeth, bland squamous nests within fibrous stroma
Micro images (Mod Path subscribers): bland squamous nests within fibrous stroma
DD: well differentiated squamous cell carcinoma, acanthomatous ameloblastoma (peripheral palisading, stellate reticulum), mucoepidermoid carcinoma
References: AJSP 1981;5:671
Malignant tumors
Obvious carcinoma but with ameloblastic features (peripheral palisading of columnar cells and resemblance to stellate reticulum)
Arise in odontogenic cysts or keratocytes
Micro images (Mod Path subscribers): primary and recurrent tumor
Rare transformation of ameloblastic fibroma
Often requires multiple excisions for recurrence; may cause death, although no metastases
Often painful
Treatment: excision
Micro: cords and rests of odontogenic epithelium in hypercellular, fibrous connective tissue composed of pleomorphic atypical cells with frequent mitotic figures
EM: fibroblasts
Previously called adimantinoma, but this term is inaccurate as it implies the presence of hard tissues, which do not occur in ameloblastomas
Note: 2005 WHO classification designates ameloblastoma as “benign”
1% of jaw tumors and cysts
Arises from remnants of ameloblast or dental lamina, dentigerous cysts, or basal layer of oral mucosa
Men and women of all ages, mean 39 years
Slow growing, locally aggressive (25-35% recur), metastases rarely to lungs or CNS
Metastases associated with tumor of long duration, multiple surgical procedures, radiation therapy
Risk factors: impacted teeth, dentigerous cyst
Xray: multiloculated, lytic, expansile radiolucent lesion
Sites: posterior mandible (80%), posterior maxilla (20%, near third molar, difficult to completely excise)
Treatment: individualized surgery
Gross: solid and cystic, may be multicystic and intraosseous or extraosseous; rarely is unicystic
Micro: columnar basal cells in palisading arrangement with vacuolated cytoplasm, hyperchromatic nuclei polarized away from basement membrane; suprabasal cells loosely textured and noncohesive, resembling stellate reticulum; no enamel or dentin formation
Microscopic patterns: (have no clinical significance)
Acanthomatous - squamous metaplasia and variable keratinization of stellate reticulum
Desmoplastic - extensive desmoplasia, often in anterior jaw
Follicular - most common, islands of odontogenic epithelium in fibrous connective tissue; epithelium resembles peripheral ameloblastic columnar cells surrounding stellate reticulum-like cells
Plexiform - irregular masses and cords of epithelial cells with minimal stroma and occasional osteoclast-like giant cells, associated with sinonasal origin tumors
Variants: intraosseous (follicular, plexiform, acanthomatous, multicystic, unicystic, granular cell [lysosomes by EM], basal cell, desmoplastic) or extraosseous (follicular, plexiform, basal cell)
Micro images: palisading basal cells and stellate reticulum; follicular pattern - low power, columnar cells surrounding stellate reticulum #1, #2, #3
Micro images (Mod Path subscribers): desmoplastic ameloblastoma
Positive stains: keratin in ameloblast cells (CK5, CK14) and stellate reticulum cells (CK 8, CK18, CK19)
EM: epithelial differentiation (tonofilaments, complex desmosomes)
DD: ameloblastoma within odontogenic cyst, squamous cell carcinoma (for acanthomatous variant)
Peripheral soft tissue variant
Men and women ages 40-60 years
Soft tissue of posterior gingiva and ascending ramus
May occur in buccal mucosa
Less aggressive than intraosseous tumors
Also called cystic ameloblastoma
Uncommon; 20% of all ameloblastomas
Mean 25 years (younger than classic type), range 8-60 years, 2/3 male
>90% in mandible, 63% at angle and ascending ramus
Less aggressive than solid or multicystic counterparts, although may expand or perforate jaw cortex and may recur
Recurrence related to fibrous wall invasion: 36% with vs. 7% without; recurrence may be long delayed
Xray: sharply circumscribed radiolucency resembling various odontogenic cysts
Xray images (Mod Path subscribers): cystic tumor penetrating cortex
Treatment: enucleation or curettage; more aggressive if invasion of fibrous wall
Case report: recurrent tumor after enucleation, Archives 1998;122:371
Gross: cystic sac or fragments of cyst wall, up to several centimeters in size
Micro: single cystic lesion lined by ameloblastic epithelium that shows typical features of ameloblastoma in some areas, including columnar basal cells in palisading arrangement with vacuolated cytoplasm, hyperchromatic nuclei polarized away from basement membrane; suprabasal cells loosely textured and noncohesive, resembling stellate reticulum, epithelial invagination, epithelial edema and separation; may have intraluminal plexiform patterns, tumor islands may invade fibrous capsule with subepithelial hyalinization
Micro images (Mod Path subscribers): edematous epithelium with basal cell palisading
DD: odontogenic cysts
References: AJSP 2000;24:1385
Clear cell carcinoma of salivary gland
Case reports in mandible and maxilla of adult women, Hum Path 1999;30:101
Micro: clear, glycogen rich cells in nests, trabeculae or single files with markedly hyalinized stroma; also smaller cells with eosinophilic cytoplasm, focal squamous metaplasia; no nuclear pleomorphism, no mitotic activity
Positive stains: keratin, EMA
Negative stains: mucin, S100, smooth muscle actin, CEA
DD: metastatic carcinoma, clear cell odontogenic tumor
Clear cell odontogenic carcinoma
Also called clear cell odontogenic tumor
Rare
Mean age 56 years, range 14-89 years, often women, usually in mandible
Low grade malignancy, with recurrence (up to 80%) and occasional metastases to regional lymph nodes or lung
Xray: poorly marginated radiolucencies
Gross: unencapsulated, infiltrates surrounding muscle
Micro: islands and sheets of clear cells containing glycogen with distinct cytoplasmic membranes and small basaloid cells with scanty eosinophilic cytoplasm; thin collagenous stroma; variable nests with palisading of peripheral cells, variable eosinophilic hyaline deposits suggestive of osteoid or dentinoid structures; perineural invasion common; minimal pleomorphism, no/rare mitotic figures, no mucin, no/minimal stellate reticulum
Micro images: H&E, CK19
Micro images (Mod Path subscribers): nests of clear cells
Positive stains: keratin, CK19, EMA, PAS diastase sensitive
Negative stains: vimentin, S100, desmin, smooth muscle actin, HMB45, alpha-1-antichymotrypsin, mucin (Alcian blue), Congo red
DD: clear cell carcinoma of salivary gland, metastatic clear cell carcinoma, clear cell variant of calcifying epithelioid odontogenic tumor
References: Archives 2001;125:1566
2/3 women, mean age 61 years
Mandibular tumors usually diffuse large B cell lymphomas in stage I, AJSP 1990;14:652
Case report of T cell Burkitt’s lymphoma in 2 year old girl with Down’s syndrome, Mod Path 1988;1:15
Ameloblastoma with classic benign histology and metastases (regional lymph nodes and lung) with benign histology
Diagnosis made only after detection of metastases
Primary tumor often occurs at younger age than nonmetastatic tumors
Case reports: 14 year old African American girl with multiple recurrences and bone metastases leading to death after 19 years (Archives 2003;127:352), with fibrosarcoma in 63 year old Japanese man (Archives 1991;115:84) [may actually be ameloblastic carcinoma]
Micro images: H&E and keratin stains
Adults: usually from breast, lung, colon, prostate, kidney, thyroid, testis
Children: usually from adrenal neuroblastoma, embryonal rhabdomyosarcoma, Wilms’ tumor
In 50%, metastases is first sign of systemic disease
Sites: tooth bearing areas, molar regions of mandible (have greater blood supply)
Rare, particularly in pediatrics
Includes primary intraosseous carcinoma, malignant ameloblastoma, malignant changes in odontogenic cysts
Case report of maxillary, pigmented tumor in 6 year old Japanese boy, Hum Path 2001;32:880
Gross: solid, gray-yellow
Micro: atypical epithelial cells
Positive stains: keratin, EMA
EM: well-developed intercellular junctions (desmosomes)
Rare
Occurs more frequently in mandible, usually ages 50+ years
Aggressive and locally destructive; recurs after enucleation
Gross: 1-6 cm
Micro: solid tumor with ameloblastoma-like sheets of odontogenic epithelium and foci of ghost cells and dentinoid
Most common primary malignant tumor of jaw
Maxillary tumors usually in alveolar ridge
Usually de novo, may occur after radiation therapy, Paget’s disease, fibrous dysplasia
Older age than osteosarcomas of long bones
Better prognosis than osteosarcoma of long bones, best at mandibular symphysis, worst at maxillary antrum
Micro: conventional findings of osteosarcoma, occasional chondroblastic component, parosteal or telangiectatic subtypes
Positive stains: p53 (48%)
References: Hum Path 1997;28:1361 (p53)
Primary intraosseous carcinoma
May arise from epithelial lining of an odontogenic cyst or denovo from intraosseous odontogenic rests
Mean age is 52 years (range 4 to 76 years); 70% occur in men (Int J Oral Maxillofac Surg 2001;30:349); most tumors (92%) occur in mandible
Progressive swelling of the jaw, pain and loosening of the teeth
Cervical nodal metastases are common
Aggressive behavior (4 year survival is 40%)
Xray: radiolucent cystic-like pattern of bone destruction, but with well-defined margins
Xray images: lytic and cystic lesion involving right mandible
Case reports: Case of the Week #73 (verrucous carcinoma #1), #2 (Tumori 2001;87:444), #3 (Oral Surg Oral Med Oral Pathol 1980;49:151)
Treatment: aggressive surgical excision (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:e29), possibly with post-operative radiotherapy
Micro: usually squamous cell carcinoma, high grade
Micro images: verrucous carcinoma - #1; #2; #3 #4; cyst lining with chronic inflammation #1; #2
References: Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:194
End of Mandible and maxilla chapter / outline