We report an unusual histopathologic finding in the endometrium from six premenopausal or perimenopausal patients who underwent biopsy for abnormal uterine bleeding. In each case the endometrial stromal cells focally exhibited a pronounced epithelioid appearance; some showed a cord-like trabecular pattern and others a signet-ring-like cell change. All raised the possibility of a metastatic malignancy, particularly from the breast. The epithelioid appearance of the stromal cells appears to be an unusual artifact occurring in a background of secretory change and predecidualization with nonmenstrual breakdown.