Intra-abdominal and psoas absceas secondary to Mvcobacterium avium complex in a patient with human immunodeficiency virus infection

Disseminated Mycobacterium avium complex (MAC) is the most common opportunistic bacterial infection in. adults infected with the human immunodeficiency virus (HIV). We describe a case of a 48 y.o. HIV positive male who responded favourably to highly active antiretroviral therapy (HAART: Stavudine, Lanuvudine, and Saquinavir), with a CD4 cell count increase from 21 to 228. After 6 months of treatment, he complained of left lower quadrant pain that was accompanied by low grade temp (100 F), chills, night sweats, chronic lower back and 22 Ibs weight loss over 6 weeks. He had no known TB exposure and was PPD negative. An abdominal CT revealed a fluid collection within the left psoas muscle with few septa that measured 5 by 3.7 cms. There was a multiloculated, multiseptate intraperitoneal collection measuring 7.4 by 5.6cms with air bubbles. The patient underwent percutaneous drainage of 1he psoas abscess that revealed frank pus. No organisms were seen on gram stain and bacterial cultures were negative. AFB smear was positive and cultures were positive for M avium complex. The patient had a clinical response to treatment with Clarithromycin, Ethambutol, and Ciprofloxacin. Although acute mycobacterial lymphadenitis has been reported upon initiation of HAART, the present case depicts an unusual manifestation of localized MAC disease in a similar setting. Here too, the immunorestorative effect of combination antiretroviral therapy may explain the atypical presentation.