Retroperitoneal cold abscess with tuberculosis of sacro-iliac joint and pubic bone: a case report of unusual presentation of osteo-articular tuberculosis.

Tuberculosis involving sacro-iliac joint and pubic bone presenting with massive retroperitoneal abscess is a rare entity. A 29-year-old female presented with history of discharging sinus in the sacrococcygeal region of 2 months duration. Plain x-ray revealed osteolytic lesion in right pubic bone and left sacro-iliac joint. Computed tomography scan revealed massive pus collection in the retroperitoneal region. Pus was drained extraperitoneally. Biopsy of the scraping of the abscess wall showed granulation tissue with foreign body type of giant cell. On follow-up the patient was doing well.