Intraductal Oncocytic Papillary Neoplasm of the Pancreas

Excerpt

A 75-year-old male with a past medical history of non-insulin dependent diabetes mellitus, coronary artery disease status-post four-vessel coronary artery bypass, remote history of heavy alcohol use, and 54 pack-year history of smoking presented to general surgery clinic for evaluation of an incidental pancreatic mass found on magnetic resonance imaging (MRI) for surveillance of renal cysts. He reported a fifty-pound weight loss over a year and was otherwise asymptomatic with a benign abdominal exam. On MRI, a 2.8 × 1.9 cm multiloculated cystic pancreatic mass with T2 signal abnormality and pancreatic ductal dilation to 6 mm was noted (Fig. 1). Endoscopic retrograde pancreatography (ERCP) with endoscopic ultrasound (EUS) confirmed the imaging (Fig. 1), and pathology from the fine needle aspirate (FNA) revealed fragments of epithelium with papillary structures and high-grade dysplasia. Preoperative serum CA 19-9 was 42 U/mL, and analysis of the pancreatic fluid revealed a normal amylase but inconclusive CEA secondary to insufficient quantity. While surgery was recommended based on the cyst appearance and high-grade dysplasia, the patient opted for surveillance. Repeat MR cholangiopancreatography (Fig. 1) 4 months later demonstrated a similar lesion and a serum CA 19-9 of 63 U/ml. He subsequently consented for surgery and underwent a laparoscopic distal pancreatectomy, regional lymphadenectomy, and splenectomy. His postoperative course was uncomplicated. Final pathology demonstrated a 2.6 × 1.9 × 1.4 cm mass obstructing the main pancreatic duct consistent with intraductal oncocytic papillary neoplasm (IOPN; Fig. 2a) as evidenced by complex papillary structures with cells exhibiting abundant granular oncocytic cytoplasm, foci of high-grade dysplasia (Fig. 2a, b), and positive staining for hepatocyte paraffin 1 immunohistochemistry (HepPar-1; Fig. 2c). Lymph nodes were negative for malignancy and the surgical margins were uninvolved by IOPN.

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