An interesting and unusual case of Bilateral Focal Osteoporotic Bone Marrow Defects (FOBMD) of the mandible, which resolved after biopsy

Focal osteoporotic bone marrow defect (FOBMD) is a rather uncommon, localized, poorly demarcated and ill-defined radiolucent, osteolytic bone lesion corresponding to the abnormal presence of hematopoietic tissue in the jaws. It is of uncertain etiopathogenesis, with a propensity for occurrence in the posterior mandible, usually in middle-aged females in their fourth to sixth decades of life, and is usually asymptomatic, being discovered as an incidental finding on routine radiographs. An unusual case of a bilateral FOBMD in a young adult male patient is presented with a detailed description of the clinical, radiographic and histopathological characteristics, and diagnostic criteria of this rare lesion. An emphasis is placed on the importance of including this pathology in the differential diagnosis of radiolucent lesions of the jaws, and on the importance of being able to distinguish it from the more common and well known conditions such as odontogenic cysts and tumors, primary and metastatic malignancies of the jaws, etc., so that undue radical treatment procedures could be avoided and appropriate management be instituted. Further, a resolution of the condition and bone deposition in the bone defects bilaterally was noted a year after the biopsies were performed, suggesting that possibly this minor intervention induced fresh bleeding into the bony cavities, reversing the ischemia that probably induced the lesions in the first place. It is likely that this encouraged bone deposition and bone fill into the hitherto osteolytic bone defects.