Tuberculosis of knee joint mimicking giant cell tumor - A case report.

A 50-year-old woman presented with pain, swelling, and reduced range of motion of right knee joint since one year. Radiograph of knee joint revealed eccentric, expansile, geographic lytic lesion on the medial epiphyseal region of tibia mimicking giant cell tumor (GCT). She underwent minimally invasive biopsy, which was positive for acid-fast bacilli and revealed necrotizing chronic granulomatous lesion, diagnostic of tuberculosis (TB). This case emphasizes to consider tuberculosis arthritis as differential diagnosis when a case of destructive giant cell tumor is encountered.