Primary tuberculous osteomyelitis of the mandible: a case report

A 10-year-old female child presented with a gradually increasing swelling of 2 months' duration on the left side of her face. The history given by the guardian was not very specific. However, the history revealed possible contact between the child and a tuberculous patient. The initial clinical and radiological evaluation indicated either a chronic residual dentoalveolar abscess, tuberculosis (TB) of the mandible or a malignancy. Routine laboratory investigations were grossly unremarkable with only the erythrocyte sedimentation rate being mildly raised. Further investigations were carried out, including a purified protein derivative test, chest screening, sputum examination, enzyme-linked immunosorbent assay for HIV and abdominal ultrasound, which were all negative. CT of the mandible showed a soft tissue mass in the submandibular region with an osteolytic lesion in the body of the mandible on the left side, and fine needle aspiration cytology (FNAC) showed the presence of a tuberculoid granuloma. FNAC, along with the clinical and radiographic findings and history, led to the diagnosis of primary TB of the mandible. Although FNAC is not as effective as an actual biopsy, it is often adequate for diagnosis and avoids a major surgical operation, which would be required for obtaining tissue for a biopsy. This case emphasises the role of proper history taking, diagnostic work-up and management. It also draws attention to the literature pertaining to the diagnosis of TB based on FNAC, especially in TB endemic areas where sophisticated tests such as the polymerase chain reaction are either unavailable or unaffordable.