Surviving Primary Pancreatic Squamous Cell Carcinoma: A Rare Entity: Presidential Poster

Abstract

Introduction: The pancreas is devoid of any squamous cells and the origin of a pancreatic carcinoma with primary squamous morphology is rarely described with little known about the natural history following treatment. Case Report: A 76-year-old Caucasian male, presented with a history of weight loss, painless jaundice and abdominal pain. His liver enzyme elevation was consistent with a cholestatic pattern. A CT abdomen revealed a 4.1 x 4.9 x 5.0 cm enhancing inhomogeneous malignant-appearing mass in the head of the pancreas with dilation of the common bile duct. Endoscopic retrograde cholangiopancreatography identified a biliary stricture and an ampullary stent was placed. Brushings from the stricture did not reveal any malignant cells. Cytological examination of an endosonographically-guided fine needle aspiration specimen confirmed the diagnosis revealing a moderately differentiated squamous cell carcinoma with no glandular differentiation and positive immunostaining for CK 5/6 and p63. No other primary site for squamous cell carcinoma was identified. Since the tumor was in close proximity to the superior mesenteric artery, the surgical risk was high. The patient was treated with concurrent chemotherapy (5-fluorouracil) and radiotherapy. The patient was closely followed with biliary stent changes and surveillance imaging. He has shown a progression free survival of 13 months, the longest so far reported in the literature. Pure pancreatic squamous cell cancer is very uncommon with an incidence of 0.5% to 2% of all exocrine pancreatic neoplasms. It is often presumed to be metastatic from another primary site unless proven otherwise. It is postulated to originate either in squamous metaplasia in a setting of chronic pancreatitis, in a pre-existing adenocarcinoma or differentiation of primitive multipotent cells with malignant transformation. CT imaging is helpful in staging or determining primary malignancies elsewhere if any. Enhancement of tumor on contrast CT and tumor blush on angiography helps to differentiate squamous cell from adenocarcinoma due to its rich vascularity. It is an aggressive tumor with a dire prognosis. Surgical resection is the best curative option but often limited by local and/or distant metastasis. Chemotherapeutic options include 5-fluorouracil, Gemcitabine and platinum based regimens, with variable success rates and a reported median survival of 3 months. We present a rare case of an aggressive primary pancreatic squamous cell cancer with the longest reported cancer free survival following chemotherapy.