Primary hydatid cyst of peritoneum presented as abdominal lump: a rare presentation.

The incidence of primary hydatid cyst of peritoneum is 2%. It can present as a palpable abdominal lump. The differential diagnosis is cystic ovarian tumor clinically and radiologically. Peritoneal hydatid disease should be included in differential diagnosis of sonographically diagnosed pelvic cystic lesion.