Intraductal tubulopapillary neoplasm of the pancreas diagnosed by endoscopic ultrasonography-guided fine needle aspiration.

A 68-year-old man with chronic alcoholrelated pancreatitis and chronic nephropathy requiring dialysis was admitted to the hospital because of a 3-day history of upper abdominal pain. Laboratory tests revealed slightly elevated C-reactive protein with normal amylase and liver function test results. Computed tomography scan of the abdomen showed pancreatic calcifications and a cystic lesion in the head/neck of the pancreas. Subsequent endoscopic ultrasound (EUS) showed a multicystic lesion (▶Fig. 1) with a dilated main pancreatic duct and a suspected solid lesion (▶Fig. 2). EUS-guided fine needle aspiration (FNA) of the suspected solid lesion in the main pancreatic duct was performed. Histopathology showed tubulopapillary structures with cylindrical cells and low grade dysplasia (▶Fig. 3, ▶Video1). There were no signs of mucin on periodic acid–Schiff and Alcian blue staining. On immunohistochemistry, the lesion was positive for CK7, CDX2 and MUC-1, and there was focal MUC6 reaction but only very few MUC5AC positive cells. The findings were consistent with an intraductal tubulopapillary neoplasm (ITPN). The patient was considered unfit for surgical treatment, and 6 months following the diagnosis he is alive without signs of disseminated disease. ITPN is relatively rare, accounting for approximately 3% of all resected pancreatic intraductal neoplasms [1]. It may be radiologically indistinguishable from intraductal papillary mucinous neoplasm (IPMN). The diagnosis is made histologically, as ITPNs exhibit a tubular/cribriform growth with only minimal luminal/ intracellular mucin, whereas IPMNs show a papillary growth pattern [2]. On immunohistochemistry, IPMNs, but not ITPNs, are MUC5AC positive [3]. Although treatment of both tumors is similar, the prognosis of patients with ITPN is typically better than that for IPMN. This might be a relevant consideration when deciding the follow-up of patients, particularly those who are poor surgical candidates. To our knowledge, ours is one of the very few published cases on the appearance of ITPN on EUS and on the utility of EUS-FNA in the differential diagnosis. Endoscopy_UCTN_Code_CCL_1AF_2AZ_3AB