A 58-year-old, postmenopausal, multiparous woman presented with a chief complaint of abnormal vaginal bleeding. Endometrial cytology was evaluated twice, revealing only squamous epithelial cells both times. Degenerated leiomyoma or uterine sarcoma was suspected from imaging findings, and total abdominal hysterectomy and bilateral salpingo-oophorectomy were therefore performed. However, histopathological examination revealed no signs of malignancy, and the patient was diagnosed as having ichthyosis uteri with uterine leiomyoma. No koilocytosis was evident, and immunostaining for p16 was also negative. Ichthyosis uteri is an extremely rare disease of unknown origin in which squamous metaplasia of the endometrium occurs across a wide area. Although regarded as a benign condition, cases have been reported in which the underlying condition was squamous cell carcinoma or endometrial adenocarcinoma. If ichthyosis uteri is present, a comprehensive approach is required, and the possibility of uterine malignancy should be considered. However, there may be no direct association between the malignant lesions and ichthyosis uteri.