Müllerian adenosarcoma of the uterus: literature review, case report, and ultrastructural observations.

This is a report of a transmission and scanning electron microscopic examination of a müllerian adenosarcoma. The neoplasm had the characteristic pattern of benign neoplastic glands with focal squamous metaplasia and a sarcomatous stroma. Ultrastructurally, both mesenchymal and epithelial elements were identified. The mesenchymal components were ultrastructurally identical to those present in endometrial stromal sarcomas, including active collagen synthesis. The epithelial component resembled bening endometrial glands, and there was significant secretory activity as evidenced by prominent cytoplasmic glycogen collections.