子宮鏡下手術により診断された子宮内膜未分化癌の症例

抄録

　Undifferentiated endometrial carcinoma is rare and accounts for only 1–2% of all types of endometrial carcinoma. We report a case of undifferentiated endometrial carcinoma diagnosed with hysteroscopic resection.

　The patient presented with hypermenorrhea and abnormal genital bleeding, and transvaginal ultrasonography revealed a simple polyp-like lesion with a smooth surface.

　Initial endometrial cytology findings showed lymphocytic infiltration without any evidence of malignancy. Hysterofiberscopy revealed a massive tumor that protruded into the uterine cavity. This mass showed a smooth surface without any bleeding or necrosis, and endometrial cancer was ruled out. We performed hysteroscopic endometrial resection, and histopathological examination of the resected specimen confirmed a diagnosis of undifferentiated endometrial carcinoma. The patient underwent hysterectomy, and no residual lesions were observed.

　Preoperative diagnosis of undifferentiated endometrial carcinoma is challenging as observed in our case. Cytological evaluation did not reveal proliferation of any atypical endometrial cells. The tumor showed a smooth surface without any bleeding or necrotic changes. We considered them to be morphological features of undifferentiated endometrial carcinoma.