Fine-needle aspiration cytology of malignant fibrothecoma of the ovary.

Fibrothecomas are common, but their malignant counterpart is extraordinarily rare. To the best of our knowledge, this is the first report on the cytologic features of malignant fibrothecoma. We had an opportunity to study it because the 70-yr-old woman refused initial surgery until the tumor reached 22 cm in size and weighed 1, 500 gm. A CT-guided fine-needle aspiration biopsy was obtained from a 5 cm left pelvic mass, which was the second recurrence within 5 yr. The smears showed large fragments of tightly packed, small, oval cells with scanty, eccentric blue cytoplasm (Diff-Quik stain), and finely granular chromatin with small central nucleoli (Ultrafast Papanicolaou stain), transected by delicate blood vessels. The tumor resembled well-differentiated carcinoma, low-grade endometrial stromal sarcoma, and other small oval cell gynecologic neoplasms. Cytodiagnosis of nonepithelial ovarian neoplasms can be difficult. However, it is not impossible, especially for recurrent tumors with previously established histodiagnosis. Diagn. Cytopath. 21:284-286, 1999. Copyright 1999 Wiley-Liss, Inc.