Solid Pseudopapillary Epithelial Neoplasm (SPEN) of the Pancreas

Abstract

SPENs are commonly observed in women in their 20s and 30s with < 10% of SPEN occurring in men(10:1). It is commonly found incidentally in asymptomatic patients undergoing abdominal imaging. SPEN is commonly found in the tail of the pancreas and sometimes in the head of the pancreas, but there are reports of the occurrence of SPEN even in other parts of the pancreas. It presents with abdominal pain or intra-abdominal mass effects such as abdominal discomfort, nausea, vomiting, loss of appetite, early satiety, or weight loss in symptomatic patients. SPEN have very low malignant potential (10–15%), but the following tumor characteristics suggest malignancy: capsular invasion, high expression of Ki-67 on immunohistochemistry, cellular pleomorphism, and high nuclear grade. It usually has a good prognosis following surgical resection. Malignant SPN is reported more commonly in the second to fifth decades of life and is typically seen in tumors measuring 6 cm or more. SPN metastasis is most commonly seen in the liver and less commonly in the lymph nodes and peritoneum.