False-positive malignant peritoneal cytology associated with pelvic endometriosis

The peritoneal washings obtained at diagnostic laparoscopy of two women with suspected endometriosis contained cells with cytologic features of adenocarcinoma. Exploratory laparotomy, total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and pelvic washings confirmed endometriosis with no evidence of cancer. At 1.5-year and 4.0-year follow-up, respectively, cancer had not developed in either patient. The authors report what they were able to find in the literature regarding false-positive assessments of malignancy obtained by cytologic examination. They also outline steps to be taken should a diagnosis of malignancy arise in a woman with endometriosis who desires pregnancy.