LAUSR

A 61-year-old female presented with an incidental finding of a pancreatic tail mass. She had been admitted for acute diarrhea and undergone abdominal computed tomography (CT) with contrast enhancement. CT showed a 2.6-cm, round, enhancing mass in the pancreatic tail (Fig. 1A). The patient had been diagnosed with essential hypertension two years ago, and she was taking antihypertensive medication. She was a non-smoker and remained abstinent for 10 years. There was no unintentional weight loss, fever, or abdominal pain. Abdominal examination showed no palpable mass. Complete blood count and liver function tests were all within the normal range. The cancer antigen 19-9 level was 9.1 U/mL (reference: <37 U/mL). Endoscopic ultrasonography (EUS) with radial echoendoscope showed a 1.9 cm × 2.3 cm, round, hypoechoic mass with well-defined margins at the pancreatic tail (Fig. 1B). There was no invasion of vascular structures or pancreatic duct dilatation. Contrast-enhanced EUS demonstrated homogenous enhancement of the mass (Fig. 1C). EUS-guided fine needle aspiration (EUS-FNA) of the mass was performed (Fig. 1D), but cytology did not reveal any malignant cells (Fig. 1E). What is the most likely diagnosis? Pancreatic Tail Mass: A Diagnostic Challenge