Teaching Case

Intra-abdominal fluid collections in a 70-year-old woman, whith fever and weight loss, 2 months after operation for aneurysm of the abdominal aorta

A-70 year-old woman was admitted to our hospital because of fever of one month's duration (390 C), weight loss, night sweats and vague abdominal discomfort. The patient reported a history of atherosclerotic aneurysm of the abdominal aorta, which was operated two months before admission. On clinical examination the patient was emaciated, pale and febrile. A mild tenderness was present on deep palpation of the abdomen. A complete blood cell count revealed a mild normocytic normochromic anemia (hemoglobin: 11.8 g/dl). A tuberculin skin test was positive. An axial contrast-enhanced CT scan of the abdomen demonstrated well-defined fluid collections, with thin wall, located at the periportal area, the peri-aortic area, and extended to the left pararenal space (Figure 1). Fluid collection was drained percutaneously (Figure 2).

Intra-abdominal fluid collections are usually hematomas or abscesses. The majority of abscesses are secondary to spinal or gastrointestinal disease, due to common pathogens [1]. In our case, biochemistry revealed that the fluid was exudate. White blood cell count was 2000/mm3 , with lymphocytic predominance. Microscopic examination of fluid samples was positive for acid-fast bacilli. Subsequent cultures yielded Mycobacterium tuberculosis, susceptible to all first-line anti-tuberculous drugs. Mycobacterium Tuberculosis is a rare cause of intra-abdominal fluid collections [2]. In our case, a meticulous clinical and laboratory evaluation failed to reveal another focus of tuberculosis. It seems that abdominal surgery was the triggering factor of local reactivation of a dormant M. Tuberculosis infection. It is well known that trauma alters the balance between host and infection, resulting in lowered tissue resistance. The patient was treated with an anti-tuberculous regimen for 12 months and she responded well.