First Report of Pancreatic Metastasis From Small Cell Carcinoma of the Urinary Bladder

Abstract

Introduction: Metastatic tumors account for only 2-5% of all pancreatic tumors and commonly originate from kidney, ovary, lung or colorectal sites. Small cell carcinoma of the bladder (SCCB) is an extremely rare malignancy, that accounts for less than 1% of all bladder neoplasms. We describe a unique report of pancreatic metastases from SCCB. Case Report: An 87-year-old Caucasian male presented to the emergency room (ER) with yellowish discoloration of skin for two weeks. His medical history was pertinent for SCCB diagnosed 5 months prior, for which he underwent robotic cystectomy with ileal conduit placement and lymphadenectomy. Post-operative imaging did not reveal metastatic disease. Currently, patient's examination was notable for scleral icterus and diffuse epigastric tenderness. Labs showed elevated bilirubin (5.5 mg/dl), alkaline phosphatase (555 U/L) and lipase (553 U/L). Computed tomography (CT) of the abdomen and pelvis with intravenous contrast revealed a pancreatic head mass measuring 4.1x4.9 cm, with dilation of the common bile duct (CBD) to 1.6 cm diameter, along with hepatic and lung metastases (Figure 1). Endoscopic ultrasound (EUS) showed an irregular pancreatic head mass of 4cm in size. Fine needle aspiration (FNA) and core biopsy were performed. During endoscopic retrograde cholangiopancreatography, biliary sphincterotomy and placement of an endoscopic 10x8mm metallic stent into the CBD were performed. Cytopathology report from the pancreatic lesion confirmed metastasis from SCCB. Upon subsequent discussion, the patient opted to pursue comfort care alone and was discharged to hospice.1420.tif Figure 1: CT scan of the abdomen and pelvis with intravenous contrast showing pancreatic head mass measuring 4.1x4.9 cm (white arrow), with biliary obstruction, distension of gall bladder and hepatic metastasesDiscussion: SCCB is a neuroendocrine tumor variant with an incidence rate of only 0.5-1% in the United States. The tumor shows male predominance and affects people in the sixth and seventh decades of life. SCCB is known to be an aggressive malignancy and can lead to widespread systemic metastases. Pancreatic involvement from metastatic SCCB is rare and to our knowledge, this is the first reported case. Most metastases to pancreas are incidentally found during an autopsy, however in our patient, given the large size and location of the tumor, the presenting feature was obstructive jaundice. EUS-FNA remains the standard technique for evaluation of pancreatic tumors and to obtain diagnostic samples to ascertain histopathology and helped in making the diagnosis in our patient.