Endometriosis in the renal area.

A case of 34 weeks pregnancy along with a large abdominal mass presented in emergency with a constant dull abdominal pain and premature labour. After delivery of the baby the dull ache persisted, prompting a laparotomy in the first postnatal week. A large cyst, arising from the left renal area and occupying almost the whole left side of the abdomen, was removed. Histopathology showed it to be an endometriotic cyst. The patient made an uneventful recovery.