Extensive peritoneal and omental lymphomatosis with raised CA 125 mimicking carcinomatosis: CT and intraoperative findings.

Diffuse peritoneal and omental seeding are well-known forms of dissemination of metastatic carcinoma. A wide variety of primary neoplasms may cause peritoneal and omental carcinomatosis, most commonly carcinomas of the ovary, gastrointestinal tract and breast. Extensive involvement of the peritoneal cavity with lymphoma is, however, rare. The association of peritoneal lymphoma with a raised CA 125, a tumour marker which is commonly raised in ovarian carcinoma, is a highly challenging clinical situation, which to our knowledge has not been published before in the medical literature. Not being aware of the possibility of this unusual combination of clinical, laboratory and imaging findings can lead to an erroneous diagnosis, as in our case.