Retroperitoneal Endometriotic Cyst Infiltrated in the Iliopsoas Incidentally Found in a Patient with Acute Back Pain.

We describe a rare case of retroperitoneal endometriotic cyst infiltrated in the iliopsoas incidentally found in a patient with acute back pain. Endometriosis at the pelvic peritoneum, including the Douglas pouch, has been reported often; there are few reports of cystic endometriosis in the retroperitoneal cavity. Today there are various theories regarding how endometriosis occurs.

Mature cystic teratoma coexisting with clear-cell carcinoma in the ovary.

Mature cystic teratoma (MCT) is the most common benign ovarian tumor; clear-cell carcinoma (CCC) is a relatively common malignant ovarian tumor in Japan, but there are few reports on the coexistence of MCT and CCC. Here we report a case of simultaneous MCT and CCC in the ovary and review the relevant literature. The patient was a 49-year-old woman.