Retroperitoneal lymphangioma mimicking malignant tumor treated by pancreaticoduodenectomy.

Lymphangiomas are classified as lymphatic malformations, which are more common in children and rare in adults. It frequently occurs in the cervical and axillary regions and uncommonly in the retroperitoneum. A 39-year-old woman presented to our department for the investigation for a 55 mm asymptomatic mass in the right anterior adrenal cavity. Abdominal ultrasound showed a tumor containing cysts in the right anterior adrenal cavity. Contrast-enhanced computed tomography showed that the tumor was poorly contrasted and ill-defined. Magnetic resonance imaging suggested that the tumor contained a small amount of fat. The tumor tended to grow, and the possibility of malignant diseases such as liposarcoma could not be excluded. Therefore, surgical resection was performed. Since intraoperative findings showed that the tumor tightly invaded to the duodenum and pancreatic head, a pancreaticoduodenectomy was selected. The entire tumor was removed without exposing the tumor. Macroscopic findings indicated that the specimen was 55 mm in size, indistinctly demarcated, yellow-white in color, and polycystic. Histologically, lymphovascular proliferation was observed with infiltration of the pancreatic head and the duodenal muscle layer. The diagnosis of lymphangioma was finally made. There was no recurrence 2 years after surgery.