Primary Pancreatic Squamous Cell Carcinoma: An Incidental Diagnosis of a Rare Entity

Abstract

Primary Squamous Cell Carcinoma (SCC) of pancreas is a non endocrine tumour showing ductal origin which accounts for approximately 0.5-2% of all malignant pancreatic tumours. Diagnosis is usually made by tissue sampling followed by comprehensive search for primary SCC elsewhere. Hereby, authors report a rare case of primary pancreatic SCC in a young female. A 46-year-old female with history of type 2 diabetes mellitus presented with abdominal pain radiating to back associated with biliary vomiting since five months. Laboratory investigations revealed mild anaemia, neutrophilic leucocytosis and elevated blood glucose. Carcinoembryonic Antigen (CEA) and Cancer Antigen 19-9 (CA 19-9) were within normal limits. Contrast-Enhanced Computed Tomography (CECT) (abdomen and pelvis) showed pancreatic atrophy, multiple stones in head and body along with a pseudocyst in tail of pancreas. Patient underwent triple phase Magnetic Resonance Imaging (MRI) with Magnetic Resonance Cholangiopancreatography (MRCP) which showed chronic pancreatitis with intraductal calculi in the head and distal body region with pseudocyst at tail region. Frey’s procedure was done and tissue sent in multiple pieces. Histopathology revealed features of infiltrating SCC in a background of atrophic pancreas. Immunohistochemistry for CK5/6, P63 and CEA was done for confirmation. It showed strong positivity for CK5/6 and P63, while CEA was negative. Final diagnosis of SCC of pancreas in a background of atrophic pancreas was rendered. Though pancreas is devoid of squamous cells, it is not uncommon to find squamous metaplasia of ductal epithelial cells secondary to chronic inflammation. In the present case, though clinical and radiological features points towards benign lesion, definite diagnosis as SCC is justified by histopathology and immunohistochemistry. Because of the rarity, diagnosis and treatment still remains a challenge.