Low-Grade Mucinous Neoplasm Arising in an Enteric Duplication Cyst of Pancreas: A Case Report and Literature Review.

Enteric duplication cysts are rare but can occur in various parts of the gastrointestinal tract, including the pancreas. Most enteric duplication cysts are benign; however, neoplastic transformation has been reported in a few cases, with adenocarcinoma being the most common malignant transformation. We present an adult with a pancreatic enteric duplication cyst and low-grade mucinous neoplasm. The patient did not exhibit any clinically significant symptoms or physical signs. Imaging revealed a cystic mass in the pancreatic head. Upon pathological examination, the cyst was found to have a bilayered muscular wall with an inner surface lined with pseudostratified mucinous columnar epitheliums. High-power microscopy revealed low-grade dysplasia in epithelial cells. The final pathological diagnosis confirmed an enteric duplication cyst with a low-grade mucinous neoplasm. To the best of our knowledge, this is the first reported case of a low-grade mucinous neoplasm occurring in an enteric duplication cyst in the pancreas. The importance of complete surgical resection and adequate pathological sampling is emphasized to avoid the missed detection of dysplasia or malignancy in these duplication cysts.