Pancreatic mesothelial cyst.

A 60-year-old woman was investigated for abdominal pain and increasing asthenia. Abdominal CT revealed a 25 mm hypodense cystic lesion in the tail of the pancreas. MRI showed a multiloculated cystic lesion, T1-hypointense and T2-hyperintense lesion, without wall enhancement. Endoscopic ultrasound detected a 25 mm multi-loculated cystic lesion, with regular margin and without pancreatic duct communication. Diagnosis of pancreatic mucinous cystadenoma was discussed and the patient was referred to surgery. She underwent distal pancreatectomy with spleen preservation. Pathological examination revealed the diagnosis of pancreatic mesothelial cyst. Histologically, the cyst was multiloculated, lined by cuboidal epithelium, ovoid nuclei and amphophilic cytoplasm, without mucin deposition or cytological atypia. Immunohistochemistry examination revealed positive staining for cytokeratin 5/6, vimentin and calretinin. At 1-year follow-up, she is in her usual health, without any symptoms.