A case of chronic expanding hematoma mimicking a cystic pancreatic tumor.

Background: A chronic expanding hematoma is an uncommon entity described as an organized blood collection that increases in size after the initial hemorrhagic event without histological neoplastic features. The standard treatment is complete resection. To our knowledge, this is the first report of a chronic expanding hematoma mimicking a pancreatic cystic tumor that has been successfully resected utilizing a laparoscopic approach.

Case presentation: We report the case of a 32-year-old man with a 10-cm chronic expanding hematoma that was preoperatively diagnosed as a cystic pancreatic tumor. Dynamic computed tomography revealed a cyst at the inferior part of the uncinate process of the pancreas without contrast enhancement. His blood biochemical data were within normal limits. The operation initially utilized a laparoscopic approach; however, the procedure was converted to hand-assisted laparoscopic surgery due to capsule adherence to surrounding organs and finally, enucleation of the tumor was performed. Pathological findings revealed a chronic expanding hematoma in the retroperitoneal space.

Conclusion: Chronic expanding hematoma in the retroperitoneal space is so rare and sometimes adheres to the surrounding tissue. It is difficult to distinguish hematoma attaching pancreas and pancreatic cyst preoperatively. In rare cases such as this, hand-assisted laparoscopic surgery is a feasible, less invasive procedure for facilitating complete resection and preventing recurrence.