- A malignant neoplasm of the ovary (counterpart of seminoma of the testis), composed of undifferentiated gonadal germinal cells and occurring more frequently in patients less than 20 years of age. The neoplasms are gray-yellow and firm, contain foci of necrosis and hemorrhage, and tend to be encapsulated; characteristically, they spread by way of lymphatic vessels, but widespread metastases also occur. SYN: disgerminoma. [dys- + L. germen, a bud or sprout, + G. -oma, tumor]
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* * *n.a malignant tumour of the ovary, thought to arise from primitive germ cells; it is homologous to the seminoma of the testis. About 15% of such tumours affect both ovaries; outside the ovary they have been recorded in the anterior mediastinum and in the pineal gland. Dysgerminomas may occur from infancy to old age, but the average age of patients is about 20 years. They are very sensitive both to radiotherapy and chemotherapy.
* * *dys·ger·mi·no·ma (dis″jər-mĭ-noґmə) [dys- + germ + -oma] the most common malignant ovarian germ cell tumor, composed of large round or polygonal glycogen-rich cells that are frequently radiosensitive and located bilaterally. It is the counterpart of the classical seminoma of the testis. The term germinoma is now used to encompass both the female and male neoplasms.
Dysgerminoma, showing polyhedral tumor cells with round nuclei and adjacent inflammation.
Medical dictionary. 2011.