Double primary prostatic adenocarcinoma.

Two cases of double primary prostatic adenocarcinoma are described. A periurethral papillary adenocarcinoma coexisted with the common acinar type of cancer, which tends to arise deep in the corpus of the gland. We are of the opinion that the patterns observed in these tumors are not mere variations of one neoplasm, but rather two dissimilar growths of diverse cell origin, varried histology, and possibly also of disparate biologic potential.