Prostatic acid phosphatase activity in carcinoid tumors

In a study of 105 gastrointestinal carcinoid tumors, 67% of the rectal carcinoids and 15% of the carcinoids at other gastrointestinal sites were positive, immunohistochemically, for prostatic acid phosphatase activity. These findings are relevant to the differential diagnosis between rectal carcinoids and prostatic carcinoma. Cancer 58:136–138, 1986.