[A case of an unusual mixed müllerian tumor in the lower uterine segment]

A unique case of a mixed müllerian tumor in a 33-year-old woman is presented. On gross examination of the hysterectomized specimen, well-circumscribed nodules, the largest measuring 3 cm in diameter, were found in the lower uterine segment. Microscopic examination revealed that the lesion was composed of a malignant glandular epithelium and a spindle cell stroma containing a smooth muscle. The atypical gland had deeply infiltrated into the normal myometrium and showed a squamous differentiation. This tumor should be differentiated from a benign mixed müllerian tumor, including an atypical polypoid adenomyoma, an adenofibroma, and an adenomyoma.