Risk factors in thyroid-type carcinoma arising in ovarian struma: a report of 15 cases with comparison to ordinary struma ovarii.

摘要

Because of its many unusual clinical and histological features, ovarian struma has elicited considerable interest in the literature. Malignant transformation has been reported in fewer than 5% of ovarian strumas, and fewer than a third of the malignant cases have spread beyond the ovary. In this study, we compare a series of 15 collected cases of malignant or potentially malignant thyroid-type ovarian neoplasms with a series of 20 consecutive cases of ovarian struma from the Clinical Oncology Research Institute, Moscow, Russia to determine which individual risk factors are useful to diagnose malignancy. Both series were analysed for clinical risk factors including stage of disease, extensive adhesions and advanced stage (II or higher), and pathological risk factors including large size of struma, vascular invasion, dispersed pattern, extension through the outer cortex to the surface of the ovary, solid areas, high mitotic count and nuclear pleomorphism. In the consecutive series, 5% of cases were histologically malignant and 5% were bilateral. The 19 cases of histologically benign ovarian struma served as the control group and were followed for a mean of 8 years with no evidence of recurrence, extraovarian dissemination or tumour-related death.