The histologic sections from patients with diagnosed endometrial adenocarcinomas were reviewed and classified according to their morphological characteristics. Sections cut from the original paraffin blocks were stained for mucin. The survival rate of patients with mucin‐producing carcinomas was compared to that of patients with equally structured nonmucinous tumors. Patients with carminophilic carcinomas survived at a 20% higher rate than those patients with mucin‐negative tumors. Within the well‐differentiated tumor group, those composed of acini, patients with mucicarmine‐positive carcinomas demonstrated a significantly greater survival rate than patients with mucicarmine‐negative tumors. Conversely, the survival rate was not appreciably altered by die presence of stainable mucin in some of die poorly differentiated adenocarcinomas. Mucin production manifests another facet of cellular differentiation reflecting functional maturity. Achieving meaningful survival rates necessitates interpretation of both morphology and function. Factors influencing die various histologic features demonstrated by endometrial adenocarcinomas are discussed.