Bone & joints
Other osteogenic tumors
Osteoma
Author: David R. Lucas, M.D.
Topic Completed: 1 August 2013
Minor changes: 29 December 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Osteoma[title]
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 March 4th, 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
Radiology images
AFIP images
Dense lobular mass in frontal sinus
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
Images hosted on other servers:
Large osteoma of maxillary sinus
Exophytic osteoma ("ivory exostosis")
Multiple bony hard swellings on forehead
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
Contributed by Dr. David R. Lucas
Osteoblastoma-like osteoma with polypoid shape and bosselated surface (left) and zones of dense, compact and trabecular bone on cut section
Contributed by Dr. Mark R. Wick
Skull
Images hosted on other servers:
Osteoma with smooth bosselated surface
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
AFIP images
Thick trabeculae of bone
Contributed by Dr. David R. Lucas
Dense, compact bone and Haversian canals
Broad trabeculae of lamellar bone
Areas indistinguishable from osteoblastoma
Pagetoid bone with basophilic reversal lines
Contributed by Dr. Mark R. Wick
Skull
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
