Immunohistochemical demonstration of multiple neurohormonal polypeptides in a case of pure testicular carcinoid.

A primary pure testicular carcinoid from a 48-year-old man was examined with antisera raised against various neurohormonal polypeptides. Histochemically, both argyrophil and argentaffin reactions were positive. The immunohistochemical finding of immunoreactive cells for 5-hydroxytryptamine (5-HT) (serotonin), substance P, and vasoactive intestinal polypeptide (VIP) demonstrated the multihormonal nature of this tumor.