Tubercular abscess of the psoas muscle

History and admission findings: A 43-year-old patient suffered from fatigue, nocturnal sweating, rigor and a weight loss of 5 kg over the last 4 weeks. A year before he had been anaemic and he was treated with omeprazole and iron. On admission physical examination was unremarkable, except for the known swelling in the rig ht flank. His general condition was good. Investigations: Computed tomography showed an extensive abscess of the right psoas muscle with deplacement of the right ureter, causing hydronephrosis, and infiltration of the abdominal wall. Cytological and bacteriological tests of the abscess aspirate indicated tuberculosis. Treament and course: The abscess markedly shrank within 2 months of starting antituberculosis treatment, wh ich was continued for another 4 months. A catheter, which had been inserted into the right ureter to relieve hydronephrosis, was remowed without further complcations. Conclusion: Because of an increase in the number of immigrants from countries with a high incidence of tuberculosis or HIV infection, extrapulmonary tuberculosis should be included in the differential diagnosis, such as in this case of a psoas muscle abscess. Despite the size of the abscess surgical intervention is rarely required because it will heal under appropriate antituberculosis treatment.