Immunomorphological manifestations of the wasting syndrome in a patient with myasthenia: thymus atrophy, reduction of the spleen lymphoid tissue, sclerosis of the lymph nodes, hyperplasia of the bone marrow, a decrease in the absolute number of T- and B-lymphocytes of the peripheral blood, intestinal necrosis, and cachexia, are first described. The condition developed along with exacerbation of the main pathological process and immunosuppressive therapy (roentgen irradiation of the thymus, cyclophosphan, hydrocortisone).