Microglandular adenocarcinoma of the uterus mimicking microglandular cervical hyperplasia.

We present a rare case of microglandular carcinoma of the uterus occurring in 76-year-old woman. The tumor tissue in the curettage specimen showed strong similarity with microglandular hyperplasia of the cervix. Microglandular aggregates of glands with only mild nuclear atypia but without any structures of conventional endometrioid carcinoma were seen. Therefore, a microglandular hyperplasia of the cervix was seriously considered. The following features were helpful in the differential diagnosis: numerous neutrophils and "dirty" amount within glandular lumens; very scarce (but nevertheless present) mitoses; isolated single glands with more endometrioid than endocervical appearance; and strong expression of vimentin, which is unusual for microglandular hyperplasia of the cervix. In the resectate, a conventional well-differentiated endometrioid adenocarcinoma with microinvasion of the myometrium (under 1 mm of depth) was found. Microglandular differentiation has been, however, present in plaque-like proliferation replacing the endometrium and on the surface of conventional adenocarcinoma. Eleven months after the hysterectomy, the patient has no signs of recurrence or metastasis. Our case shows the difficulties in the diagnosis of this lesion and confirms a low aggressiveness that was observed in all 10 cases described to date.