Papillary projections focally involve the surface epithelium in this endometrial biopsy.
At higher power, cells with abundant eosinophilic cytoplasm can be appreciated.
Eosinophilic syncytial change (ESC), also known as papillary syncytial change, is relatively common finding and may be present in up to 17% of endometrial biopsies.1 It consists of syncytial aggregates of cells with abundant eosinophilic cytoplasm, forming papillary structures along the surface epithelium.
ESC is thought to be associated with physiologic glandular and stromal breakdown, however, there have been various theories regarding ESC as part of a proliferative, regenerative and even pathologic process.1 A recent study by Shah and Mazur lends support for ESC as a benign marker of degeneration and breakdown. 15 cases of ESC associated with benign endometrium, 5 cases of atypical hyperplasia and 7 cases of endometrical carcinoma were stained with Ki-67 and pHH3, markers of mitotic and proliferative activity. Ki-67 labeling for ESC was 1.3%, 15.8% for atypical hyperplasia and 42.6% for endometrial carcinoma. Similarly, the mitotic index (calculated from pHH3) was zero for ESC, 2.3% for atypical hyperplasia and 2.4% for grade I carcinomas, 3% for grade II carcinomas and 7.8% for serous carcinomas.2
1 Zaman SS, Mazur MT. Endometrial papillary syncytial change. A nonspecific alterative associated with active breakdown. Am J Clin Pathol. 1993;99:741-5.
2 Shah SS, Mazur MT. Endometrial Eosinophilic Syncytial Change Related to Breakdown: Immunohistochemcial Evidence Suggests a Regressive Process. International Journal of Gynecological Pathology. 2008;27:534-8.