Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Lucas DR. Osteoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/boneosteoma.html. Accessed April 18th, 2021.
Definition / general
- Benign bone forming tumor composed of compact or mature trabecular bone limited almost exclusively to craniofacial bones, especially paranasal sinuses (Arch Pathol Lab Med 2009;133:1587)
Terminology
- Ivory exostosis, sino orbital osteoma, sino nasal osteoma
Epidemiology
- Adults and children, mean age 37 years
- Men outnumber women, 3:2
Sites
- Paranasal sinuses (frontal sinus most common), orbit, nasal cavity, jaw bones, cranial vault
Etiology
- Unknown
Clinical features
- Paranasal sinus tumors associated with pain, headache, facial distortion, proptosis, visual changes, mucocele, sinusitis, CSF leakage, pneumatocele, meningitis, and cerebral abscess
- Associated with Gardner syndrome
Diagnosis
- Radiographic findings often helpful
Radiology description
- Well demarcated tumors
- Dense compact bone with varying amounts of central lucency
Prognostic factors
- Prognosis related to proximity to essential anatomic structures and completeness of resection
- ~20% have symptomatic recurrences
Case reports
- 39 year old woman with multiple peripheral osteomas of forehead (Ann Med Health Sci Res 2013;3:105)
- 61 year old man with frontoethmoid osteoma and pneumocephalus (J Craniofac Surg 2013;24:953)
- 71 year old man with recurrent frontal osteoma, mucopyocele and M. catarrhalis abscess (World Neurosurg 2012 Nov 29 [Epub ahead of print])
Treatment
- Surgical excision for symptomatic tumors
Clinical images
Gross description
- Sessile, polypoid shape
- Median size 3.0 cm (range 0.5 - 8 cm)
- Smooth, bosselated surface
- Cut surface with dense compact bone (ivory osteoma), trabecular bone (mature osteoma, or both patterns)
Gross images
Microscopic (histologic) description
- Composed primarily of dense, compact bone and broad trabeculae of mature bone within paucicellular fibrous stroma
- Outer surface is sharply demarcated and lined by respiratory epithelium in sinus tumors
- Areas resembling osteoblastoma (narrow, anastomosing trabeculae of woven bone with osteoblastic rimming within a fibrovascular stroma) are common (38%)
- Pagetoid bone common
Microscopic (histologic) images
Differential diagnosis
- Ossifying fibroma: more cellular fibrous stroma, small ossicles and irregular bony trabeculae, much less mature bone
- Osteoblastoma: rarely found in paranasal sinuses, expansile intraosseous or periosteal tumor, much less mature bone