Focal osteoporotic bone marrow defect: A happenstance finding

Focal osteoporotic bone marrow defects (FOBMDs) of jaws are rare and usually discovered as an incidental radiographic finding. They present as a poorly demarcated radiolucency affecting the posterior mandible of middle-aged women with pathogenesis remaining unknown. A 60-year-old female patient had visited our dental college for routine dental checkup and oral prophylaxis. Her radiograph revealed a well-defined radiolucency in the left mandibular posterior region as an incidental finding. Clinical examination revealed a diffuse swelling in the above-mentioned region which the patient had not noticed. The patient gave a history of trauma in the same region almost 20 years back. Incisional biopsy was performed. Microscopic examination revealed multiple bits of fatty fibro cellular tissue resembling the bone marrow with aggregates of blood cells. A diagnosis of FOBMD was given. FOBMD, although rare, should be included in differential diagnosis of the radiolucent lesions of the jaws.