Endoscopic Ultrasound-Guided Fine Needle Aspiration Used for the Diagnosis of a Retroperitoneal Abscess. A Case Report

Abstract

Background. The evaluation of idiopathic abdominal masses by EUS-guided fine needle aspiration (FNA) is considered a feasible and safe option. Moreover, different case reports and small case series recently described EUS-guided drainage of abscesses located nearby the digestive tract as a viable option of mini-invasive treatment.

Case report. We present the case of a young patient with a retroperitoneal abscess diagnosed by EUS-guided FNA. Trans-abdominal ultrasound (TUS) and computer tomography (CT) scan were helpful, but insufficient for the final diagnosis. Although the abdominal mass was clearly visualized by these imaging methods, it was not possible to differentiate between a cystic tumor mass and an abscess. The mass was located in the vicinity of the pancreas tail, near the spleen and superior pole of the left kidney. The case management was complex due to the associated disorders and occurrence of severe episodes of hemolytic anemia. The association of gastric varices and left-sided portal hypertension further complicated the differential diagnosis and precluded percutaneous aspiration procedures. EUS-guided FNA established the final diagnosis, because of pus aspiration and positive bacterial cultures that sustained the initial supposition. The patient was referred to surgery and the evolution was favorable after abscess drainage and splenectomy.

Conclusion. EUS-FNA is an excellent option used to obtain a tissue diagnosis in suspicious retroperitoneal masses, with a clear impact for the management decisions of these patients.