Diagnosis of pancreatic tuberculosis by combined, contrast-enhanced sonography and endoscopic ultrasound-guided fine-needle aspiration.

Abstract

A 79-year-old woman complaining of epigastric pain was examined by her local physician, who found an abdominal mass and referred the patient to our department. Abdominal plain computed tomography revealed a mass, 50mm in size, with slight calcification on the ventral side of the head of the pancreas. On abdominal ultrasound, the mass lesion consisted of an aggregation of hypoechoic masses, with a heterogeneous hyperechoic region at its center. On contrast ultrasonography, only the hyperechoic region was stained. (18)F-Fluorodeoxyglucose-positron emission tomography (FDG-PET) revealed FDG accumulation in the same region. It was difficult to differentiate between a malignant pancreatic tumor and an inflammatory disease on imaging, but since QuantiFERON TB2G testing was positive, pancreatic tuberculosis was suspected, and endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) was performed to obtain a definitive diagnosis. Samples from the hypoechoic region consisted of necrotic tissue, while those from the hyperechoic region consisted of pancreatic tissue together with granulation tissue. BCG immunostaining was positive, and a diagnosis of pancreatic tuberculosis was made. If EUS-FNA is performed on stained areas seen on contrast ultrasonography, this will probably enable a more accurate diagnosis of pancreatic tuberculosis with low invasiveness.