A rare case of primary peritoneal hydatid cyst

Primary peritoneal hydatid cyst is a rare entity. A 42 yr old parous female presented with painless lower abdominal lump since 6 months. On clinical examination an immobile abdominopelvic lump of the size of 18-20 weeks pregnant uterus with bosselated surface was noted. Ultrasound Sonography Test (USG) and Contrast Enhanced Computerized Tomography Scan (CECT scan) of abdomen and pelvis revealed large multilocular abdominopelvic cystic mass in continuity with RT ovary. Radiologically a differential diagnosis of hydatid cyst and mucinous cystadenoma was made. All relevant ovarian tumor markers were normal. Serology confirmed increased Echinococcus IgG antibodies (196.60 U/ml, ELISA). The patient underwent complete surgical excision of the lump. Histopathology and Hematoxylin and Eosin (H and E) staining of the aspirate from the cyst confirmed the diagnosis of hydatid cyst. Since no other organs were involved it was diagnosed as a case of primary peritoneal hydatid cyst. The hydatid cyst may mimic an ovarian cyst, thus it is important to keep this rare entity in mind as a differential in ultrasonographically diagnosed pelvic cystic lesions