A malignant mixed mesodermal tumor of the uterine corpus with hypercatecholaminemia

We report an unusual case of malignant mixed mesodermal tumor of the uterine corpus associated with various symptoms related to overproduction of catecholamine by the tumor cells. Histologically, the tumor was dominated by carcinomatous epithelium with foci of malignant mesenchyma. The type of epithelium was endometrioid with papillary adenocarcinomas containing foci of malignant squamous epithelium. The malignant mesenchyma consisted mainly of a fibrous stroma with many large and bizarre cells and spindle cells mimicking leiomyosarcoma, many of which were pleomorphic and contained large bizarre hyperchromatic nuclei. Foci of atypical adult-type cartilage and neoplastic osteoid formation were noted. In the tumor tissue, membrane-bound neurosecretory-type cytoplasmic granules were demonstrated by electron microscopy and polypeptide hormone synthesis was demonstrated by immunohistochemistry. Furthermore, the patient suffered frequent attacks of sudden hypertension with hypercatecholaminemia.