Lipofuscin in human tongue muscle.

In a study of 107 tongue specimens lipofuscin granules were found to be present in the muscle fibers of 93% of the cases. The pigment was not found in young individuals under the age of 18 years. The pigmented granules, which were stored in clusters of different sizes at the nuclear poles, were PAS-positive, stained black or brown with the Masson-Fontana procedure, black with Sudan black, and strong purple-pink with Ziehl-Neelson staining; yellow autofluorescene was emitted in ultraviolet light. The morphology, histochemical reactions and autofluorescence of the pigmented granules were characteristics of the endogenous lipid pigment described as lipofuscin. Statistical analyses indicated a direct correlation between increase in quantity and distribution of the pigment and increase in age (P = 0.001), in both males and females. Accumulation of the pigment in the tongue with aging was found to be similar to that in the myocardium.