ENDOMETRIOID CARCINOMA OF THE OVARY AND ENDOMETRIUM, OXYPHILIC CELL-TYPE - A REPORT OF 9 CASES

Six endometrioid carcinomas of the ovary and three of the endometrium composed predominantly or entirely of large eosinophilic (oxyphilic) c ells are reported. The ovarian tumors occurred in women 31-75 years of age, with a mean of 58 years, and the endometrial tumors occurred in women 37-50 years, with a mean of 44 years. All the ovarian tumors and one endometrial tumor contained focal areas typical of endometrioid c arcinoma, with round to oval tubular glands lined by simple or stratif ied columnar cells and focal squamous differentiation. Two endometrial tumors were composed almost exclusively of oxyphilic cells lining gla nds. One endometrial tumor contained prominent luminal and intracytopl asmic mucin. Five of the ovarian tumors were grade 2/3 and one was gra de 3/3, whereas two of the endometrial tumors were grade 1/3 and one w as grade 2/3. The prominence of the oxyphilic cells posed diagnostic d ifficulty in most of the cases. Electron microscopic examination perfo rmed on all tumors showed abundant mitochrondria in only one, an ovari an tumor. Other organelles, especially microfilaments and tonofibrils, are cited as other possible reasons for the eosinophilia. Four of the nine cases were recent; follow-up of the remaining five showed a biol ogical behavior similar to the typical endometrioid carcinoma of the o vary and endometrium. We suggest that the diagnosis of ''endometrioid carcinoma, oxyphilic cell type'' is appropriate for this variant of ca rcinoma largely composed of eosinophilic cells that may or may not be ''oncocytic'' in nature. The importance of recognizing this entity lie s in distinguishing it from diverse other primary and metastatic oxyph ilic cell tumors of the ovary and eosinophilic cell metaplasia and rar e other types of primary carcinoma with eosinophilic cells of the endo metrium, which may be especially challenging in a curettage or biopsy specimen.