Intra-Abdominal Nocardiosis-Case Report and Review of the Literature

Abstract

Nocardiosis is primarily an opportunistic infection affecting immunosuppressed individuals, in whom it most commonly presents as pulmonary infection and sometimes cerebral abscesses. Isolated abdominal or retroperitoneal nocardiosis is rare. Here, we report the second case, to our knowledge, of isolated abdominal nocardiosis due to Nocardia paucivorans and provide a comprehensive review of intra-abdominal nocardiosis. The acquisition of abdominal nocardiosis is believed to occur via hematogenous spreading after pulmonary or percutaneous inoculation or possibly via direct abdominal inoculation. Cases of Nocardia peritonitis have been reported in patients on peritoneal dialysis. Accurate diagnosis of abdominal nocardiosis requires histological and/or microbiological examination of appropriate, radiologically or surgically obtained biopsy specimens. Malignancy may initially be suspected when the patient presents with an abdominal mass. Successful therapy usually includes either percutaneous or surgical abscess drainage plus prolonged combination antimicrobial therapy.

Keywords: Nocardia paucivorans; abdominal; abscess; immunosuppression; infection; malignancy; nocardiosis; retroperitoneal.

Figure 1

Upper row: 11 × 6 cm retroperitoneal mass in the right adrenal loge (thin white arrows) with contact to diaphragm, liver and retroperitoneal vessels. The pararenal space is not involved. The mass shows an inhomogeneous enhancement. The right adrenal gland itself cannot be distinguished. Lower row: Mass after puncture and CT guided drainage with a pigtail catheter (thick white arrow).

Figure 2

(A) Histologic examination of a retroperitoneal biopsy specimen demonstrates a diffuse neutrophilic infiltrate with necrosis and cellular debris. High magnification of a typical area of one of these abscesses with neutrophils, debris and liquefactive necrosis. Organisms are not visible on routine H&E stain. (B,C) Gram stain shows filamentous bacteria (arrows), consistent with Nocardia species. The organisms are Gram-variable or weakly Gram positive, thin and filamentous, and focally concentrated.