A usually aggressive morphologic variant of acinar adenocarcinoma of the prostate gland characterized by the presence of lakes of extracellular mucin. This diagnosis applies when at least 25% of the resected tumor contains extracellular mucin. The disease is Monarch Disease Ontology identifier MONDO_0006067 (acinar prostate mucinous adenocarcinoma). Also known as: acinar colloid prostate adenocarcinoma, colloid adenocarcinoma of prostate, colloid adenocarcinoma of the prostate, colloidal adenocarcinoma of prostate, colloidal adenocarcinoma of the prostate, colloidal prostate adenocarcinoma, mucinous adenocarcinoma of prostate, mucinous adenocarcinoma of the prostate.