Abstract
We report an autopsy case of a 47-year-old diabetic woman with MELAS. After the onset of deafness at the age of 25 years, diabetes, dilated cardiomyopathy, renal failure, dysarthria, syncope, and muscle weakness gradually progressed. The diabetes and deafness were maternally inherited. The patient was admitted because of syncope and shoulder pain. Her renal failure was so severe as a result of rhabdomyolysis that hemodialysis was instituted. However, the patient died of sepsis on the6th hospital day. Pathological examination showed characteristic findings of MELAS, such as ischemic change and calcification of the basal ganglia in the brain, ragged-red fibers in the skeletal muscles, and smooth muscle degeneration. The proportion of mitochondria with the 3243 mutation was 38% in the pancreas, 14% in the peripheral blood, and more than 50% in the brain, heart, liver, stomach, and kidney. Hematoxylin-eosin staining of the pancreas showed that the islets were atrophic, and their acidophilicity made it difficult to discriminate the islet contours from the exocrine tissue. Immunohistochemical staining showed a marked decrease in the number of β-cells, but α-cells were well maintained. These findings contrast with previous reports that both α and β cells were equally atrophic in cases with MELAS.
