Primary Tuberculosis Presenting as a Soft Tissue Mass in the Sacroiliac Joint of an Immunocompetent Patient: A Case Report

Abstract

A 46-year-old immunocompetent Somali female immigrant presented with a 2-year history of progressive left hip pain refractory to conservative management. Magnetic resonance imaging revealed a large mass arising from her left sacroiliac joint and extending into her left gluteus maximus. Biopsy and culture identified an abscess of unknown etiology, prompting an incision and drainage. This abscess was later identified as primary tuberculosis, for which she was placed on an antitubercular regimen and had complete resolution of her symptoms. Primary tuberculosis, while extremely rare, should be considered on the differential for a complex sacroiliac abscess, particularly in patients from endemic countries.