Carcinosarcoma of the spermatic cord.

The first case of carcinosarcoma in the spermatic cord is reported in a 40-year-old man. The tumor was a 2.5 X 2 cm pseudoencapsulated formation located in the connective tissue of the spermatic cord among the blood vessels. Light microscopy examination of the neoplasm revealed two different histological patterns: epithelial and sarcomatous. Mitoses and atypias were infrequent in both types of areas. The epithelial cells formed papillary and gland-like structures stained with PAS, Hale and mucicarmine stains, and showed positive reaction for immunohistochemical demonstration of both keratin and epithelial membrane antigen. The lumen content of the gland-like structures reacted positively for the carcinoembryonic antigen. Electron microscopy revealed that the epithelial cells were joined by junctional complexes and displayed numerous short microvilli. The sarcomatous areas consisted of spindle cells embedded in a ground substance that occasionally presented myxoid changes. Mast cells and focal calcifications were seen. Sarcomatous cells showed positive reaction for vimentin but not for the other histochemical and immunohistochemical techniques mentioned above. The ultrastructure of sarcomatous cells was similar to that of epithelial cells except for the occurrence of small desmosomes instead of junctional complexes. The differential diagnosis with adenomatoid tumor and malignant mixed mesothelioma is discussed.