Bone and Soft-Tissue Disorders
= benign tumor of membranous bone (= hamartoma)
Histo: mature compact / cancellous bone
Age: adult life
Associated with: Gardner syndrome (multiple osteomas + colonic polyposis)
Location: craniofacial bones
- inner / outer table of calvarium (usually from external table)
- paranasal sinuses (frontal / ethmoid sinuses)
- mandible (posterior body / condyle)
- non–tooth-related circumscribed sclerotic mass
DDx: idiopathic osteosclerosis WITHOUT bone expansion cannot be differentiated from osteoma. - nasal bones
- well-circumscribed round extremely dense structureless lesion usually <2 cm in size
- ± bone expansion / exophytic growth
- NO perilesional halo
Fibrous Osteoma
Probably a form of fibrous dysplasia
Age: childhood
- less dense than osteoma / radiolucent
- expanding external table without affecting internal table
DDx: endostoma, bone island, bone infarct (located in medulla)