Rare case of sacrococcygeal tuberculosis mimicking as an anal fistula

INTRODUCTION: Spinal tuberculosis (TB) is the most common manifestation of extra-pulmonary TB. TB of the lumbosacral junction is rare and occurs in only 1 to 2% of all cases of spinal TB. Moreover, isolated sacrococcygeal TB is extremely rare. Herein, we report a rare case of sacrococcygeal TB, which was difficult to distinguish from complex anal fistula. CASE PRESENTATION: A 93-year-old man presented with sacral pain and peri-anal discharge. He had pulmonary TB at 25 years of age. Fistulography revealed an abnormal tract that connected to the pre-sacrococcygeal area, which was not connected to the rectum. Computed tomography scan showed fluid collection in front of the sacrum, with a lytic destruction of the lower sacrum and coccyx. Cold abscess aspiration cytology was negative for acid-fast bacilli. However, real-time polymerase chain reaction was positive for Mycobacterium tuberculosis. His symptoms resolved immediately after the initiation of anti-TB chemotherapy. CONCLUSION: This case highlights the importance of considering tuberculosis as a diagnosis if the unusual sites are involved.