Benign mixed mesenchymal tumor of the spermatic cord.

We report a case of benign mixed mesenchymal tumor consisting of spindle cells and an area involving osseous elements. Immunohistochemical investigation revealed the spindle tumor cells to express vimentin and the alpha-subunit of S100 protein, but no staining for other specific antigens. The findings thus suggest that the spindle tumor cells are undifferentiated in nature and derived from mesenchyma, the osseous component being interpreted as evidence of a specific differentiation.