A metastatic granulosa-theca cell tumor of the ovary was studied by electron microscopy for the first time. The tumor cells showed cytoplasmic features similar to those of nonmalignant ganulosa cells. Marked nuclear alterations, corresponding to the appearance of embryonic granulosa cells, were present. Cells varying in shape from round to elongated were otherwise identical in terms of cytoplasmic architecture and nuclear abnormalities. The significance of ultrastructural abnormalities in evaluating granulosa-theca cell tumors is discussed.
RANULOSA-THECA CEI.1, TUMORS COMPRISE
G 8% of all malignant and potentially malignant ovarian neoplasms.27 The rate of malignancy ranges from 5.8%4 to 53%14 in various series, with an average recurrence rate of approximately 25%.21 The malignant potential of granulosa cell tumors cannot be determined by the usual histologic criteria since the cellular pattern, number of mitoses, and degree of cellular pleomorphism have not been reliable indicators of recurrence rate.21 As a result, prognosis is usually impossible to predict even after thorough tissue examination. Although Kottmeierlc found a higher rate of malignancy in those tumors with a sarcomatoid pattern, no consistent histologic differences have been recognized between granulosa cell tumors that recurred and those that did n0t.29
The use of electron microscopy in studying surgical specimens has afforded an opportunity to examine the histologic features of granulosa cell tumors in greater detail than previously possible. Similarity in ultrastructural appearance of neoplastic and normal granulosa cells has been noted in 2 prior electron microscopic reports of granulosa cell turnors.19~ 29 In the present report, which is the first electron microscopic study of a metastatic granulosa cell tumor, some significant nuclear and cytoplasmic alterations are described in the malignant granulosa cells.