Carpal synovitis with capitate bone tuberculosis in a child

We present a 10-year-old boy with 2-month duration non-traumatic wrist pain and inflammatory signs. Due to elevated inflammatory markers on blood tests, with an increase in radiocarpal and intercarpal joints synovial fluid and no bony lesions, the patient was submitted to wrist arthrocentesis for the suspicion of septic arthritis. The patient did not improve on conventional treatment, however. An MRI showed synovitis around the carpus and a lytic lesion of the capitate bone due to osteomyelitis. A biopsy was able to identify the causative agent as Mycobacterium tuberculosis, and the patient was treated with antibiotics. He improved significantly, with no pain and signs of normal capitate bone remodelling on the last radiograph.