Mucinous adenocarcinoma of the prostate.

A case of mucinous adenocarcinoma of the prostate that was diagnosed with the aid of prostate-specific antigen immunoperoxidase staining is reported. Focal areas of the tumor, which were morphologically similar to the remainder of the tumor, stained with neuron-specific enolase by an immunoperoxidase technique and with the Grimelius stain. This tumor is best thought of as a variant of the classic acinotubular adenocarcinoma of the prostate with well-differentiated cells that secrete mucin, rather than as a completely different type of cancer, as proposed previously.