Yin and yang of Pott's disease.

A 45-year-old man co-infected with HIV and hepatitis C was admitted with low-grade fever, abdominal pain and a protrusive mass in the flank. He had been taking highly active antiretroviral therapy regularly for 2 years, his viral load was below 50 copies/ml and his CD4 cell count was 216 cells/μl. Abdominal computerised tomography showed lytic lesions on the L3 and L4 vertebrae (fig 1A, arrow), a sinus tract to the abdominal cavity and and abscess, resembling the Chinese yin/yang symbol, on psoas muscle bilaterally, on the right side (fig 1B, arrowheads). A tuberculin skin test produced a 25-mm induration and a purulent liquid was drained from the abscess. A smear for acid-fast bacilli and a culture for tuberculosis were negative. Polymerase chain reaction revealed infection with Mycobacterium tuberculosis. He had no neurological involvement and bed rest was recommended to avoid complications. Treatment with rifampicin, isoniazid, and pyrazinamid was started. Percutaneous drainage was performed twice more and then the patient was discharged. Five months later he was asymptomatic, the abdominal mass had subsided and he was receiving rifampicin and isoniazid. Figure 1 Abdominal tomography showing lytic lesion on the L3 and L4 vertebrae (panel A), and bilateral abscess formation on the psoas muscle (panel B). Tuberculous spondylitis (Pott’s disease) is the most common presentation of osseous tuberculosis. The description of Pott’s disease and AIDS is restricted to a few reports.1,2 This chronic, slowly progressive disease usually involves the lower thoracic and the lumbar vertebrae and the intervertebral disc. In settings with high prevalence rates of tuberculosis, such as Brazil, this presentation must be considered even in patients with stable HIV disease.3