Ileus in mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes

Patient: A 39-year-old woman with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) who developed paralytic ileus and died of irreversible shock. Methods: Abdominal X-ray, autopsy using light microscopy, electron microscopy and mitochondrial DNA analysis. Results: Paralytic ileus was diagnosed. Several hours after admission the patient died from irreversible shock. At autopsy, ultrastructural examination of the small intestine revealed abnormal accumulation of mitochondria in smooth muscle cells. DNA analysis of the intestinal tissue showed a tRNA(Leu(UUR)) A→G transition at nucleotide position 3243 of the mitochondrial DNA. The amount of mutated mitochondrial DNA was markedly higher in the lamina muscularis than in the mucosa: 30% vs. 8%. Conclusions: Paralytic ileus may be due to mutated mitochondrial DNA which ultimately leads to smooth muscle dysfunction in the small intestine. Recognizing mitochondrial DNA abnormalities as a new etiopathogenetic factor of paralytic ileus may become more important in clinical medicine in the near future.