Clinical Characteristics of Patients in Japan with Ovarian Cancer Presumably Japan with Ovarian Cancer Presumably Arising from Ovarian Endometrioma

Objective: To investigate the clinical features of patients in Japan with malignant transformation of ovarian endometrioma. Patients: Thirty-three patients diagnosed with ovarian cancer presumably arising from endometrioma were recruited retrospectively. These patients had been followed for at least 2 years after the ovarian endometrionna diagnosis, then continued to be followed after they had been found to have malignant transformation. Results: The average age of the patients was 47.7 +/- 9.3 years; 75.7% were premenopausal at the time of diagnosis of ovarian cancer. Among the 33 patients, ovarian cancer developed in the ipsilateral ovary of 6 patients with endometrionna after cystectomy. Twenty-eight patients were diagnosed with stage I ovarian cancer, and major histotypes were clear cell in 23 cases and endometrioid in 8. Before surgery for cancer, mural nodules within the endometrionnas were detected in 32 patients, and 1 patient had a small 3-mm nodule. In 30 patients, the diameter of the tumor doubled in size 6 months prior to the diagnosis of malignant transformation. The diameter of the endometrioma and the preoperative CA125 value did not significantly correlate. Conclusions: To detect malignant transformation of ovarian endometrioma early and precisely, the clinician should determine the existence of a mural nodule and assess the rapid growth of the endonnetrionna. (C) 2014 S. Karger AG, Basel