A case of serous cystic neoplasm with form changes on an image obtained during long-term follow-up

A 45-year-old man presented with a 24-mm macrocystic lesion at the pancreatic head, which was detected by computed tomography (CT). During six years of follow-up, CT, MRI, and endosonographic images of the cystic lesion showed that the cystic lesion had enlarged to 42mm, with the appearance of a thick cyst wall. Since a cystic tumor could not be ruled out, surgery was performed. Pathological examination of the resected specimen revealed microcystic-type serous cystadenoma of the pancreas, with the presence of internal bleeding in the cyst and hemorrhage and thick fibrous tissue in the cyst wall. We could observe a serous cystic neoplasm with prismatic form changes on an image obtained during long-term follow-up. Thus, we considered this case to be useful for investigating the natural history of serous cystic neoplasm of the pancreas.