Cystic lymphatic malformation of the pelvis mimicking seminal vesicle cysts.

A 6-year-old boy presented with fever of 2 days of duration and had blood tests demonstrating leukocytosis and impaired liver function. Abdominal sonogram incidentally revealed 2 cystic lesions within the pelvis. Further contrast-enhanced abdominal computed tomography showed a symmetrically bilobed cystic mass between the urinary bladder and rectum in the location of the seminal vesicles. The boy underwent surgical excision, and the histopathology confirmed the mass as a cystic lymphatic malformation originating from the mesentery of the sigmoid colon.