Abstract
A case of advanced primary hypothyroidism occurring in an adult woman is discussed. Morphologically the condition was characterized by fibrosis and atrophy of the thyroid, and by myxomatous changes in cardiac and striated muscle and the corium of the skin. Associated findings were atrophy and lipoid depletion of the adrenal cortex. Qualitative histochemical studies with the periodic-acid Schiff technique indicated that the peculiar degeneration and myxoma-like edema within the skin, cardiac and striated muscle are related in the presence of a mucopolysaccharide.