Malignant mixed germ cell tumors of the ovary. A clinical and pathologic analysis of 30 cases

The clinical and pathologic features of 30 ovarian mixed germ cell tumors (neoplasms containing combinations of malignant germ cell elements) were studied to determine their behavior and to compare them with pure forms of malignant germ cell tumors. Dysgerminoma was the most common constituent, found in 24 (80%), followed by endodermal sinus tumor in 21 (70%), teratoma in 16 (53%), choriocarcinoma in 6 (20%), and embryonal carcinoma in 5 (16%). The actuarial survival for the entire group was 46%, and for patients with Stage I tumors it was 50%. The most important factors in predicting the prognosis for patients with Stage I disease was the size and the histologic composition of the neoplasm. If more than one-third of a Stage I neoplasm was composed of endodermal sinus tumor, choriocarcinoma, or Grade 3 teratoma, the prognosis was poor, whereas if the tumor contained less than one-third of these components or contained combinations of dysgerminoma, embryonal carcinoma, or Grade 1 or 2 teratoma, the prognosis was excellent. All patients whose neoplasm was less than 10 cm in maximum diameter survived, regardless of the composition of the tumor. Positive pregnancy tests in nonpregnant patients reflected the presence of either frank choriocarcinoma or scattered syncytiotrophoblastic giant cells. The latter did not appear to alter the prognosis. The finding of elevated serum levels of human chorionic gonadotropin (hCG) in 38% of the nonpregnant patients suggested that serial serum assays for hCG might be useful in staging and monitoring the response to treatment in these patients.