Background: Paraovarian cysts are frequently asymptomatic and usually not considered in differential diagnosis of large pelvic masses.
Case Report: A rare case of a large cyst of paraovarian origin filling up the whole abdomen is presented. Preoperative diagnostic studies including transvaginal ultrasonography and magnetic resonance
image were insufficient for correct diagnosis. Postoperative diagnosis was serous cystadenoma
of paraovarian origin.
Conclusions: Paraovarian masses could be the origin of large abdominal masses of pelvic origin. Clinical and pathological of paraovarian cysts are briefly discussed.

Keywords: Paraovarian mass, serous papillary cystadenoma