Tuberculosis of the spine presenting with a cold abscess through the lumbar triangle of Petit.

The increasing incidence of human immunodeficiency virus (HIV) has resulted in an increase in the number of Mycobacterium tuberculosis (TB) infections worldwide. Musculoskeletal tuberculosis often involves the spine. Due to HIV, patients may present atypically and, as a result, a high clinical suspicion is necessary to avoid the catastrophic consequences of untreated Pott's disease of the spine. A cold abscess as a result of tuberculosis can emerge in a number of anatomical regions, and perhaps most notably as a psoas abscess. We report a less common anatomical location of a cold abscess, presenting as a mass in the inferior lumbar region through the lumbar triangle of Jean-Louis Petit. We consider the route that the pus had followed and highlight the need for vigilance when dealing with an abscess in this region, particularly in communities with a high incidence of HIV infection.