2014 Volume 30 Issue 2 Pages 205-214
We present a case of a female infant with mitochondrial disease histologically proved histiocytoid cardiomyopathy (hcCMP).She was born full-term but small for gestational age. She could not suck well and had high serum lactate levels.Echocardiography performed just after birth revealed normal left ventricular contractility at rest, but showed impaired systolic and diastolic function at crying. She initially had characteristic features of left ventricular non-compaction, but thereafter turned to have hypertrophic cardiomyopathy (HCM). At 4 months of age, she developed encephalopathy. Clinical signs and symptoms led us to suspect mitochondrial disease. In spite of treatments with coenzyme Q10, creatin, vitamins B, C, and E, and carnitin, she showed severe acidosis at 6 months of age. She deteriorated and died at 7 months of age because of multiple organ failure.At autopsy, the macroscopic-view showed hypertrophied cardiac muscle, with marked disseminated yellowish areas and hypertrabeculation. The microscopic-view of the myocardium was characterized by histiocyte-like cells with foamy or granular cytoplasm. The electron microscopic-view showed ballooning of mitochondria and decreased density of cristae. The diagnosis of hcCMP was made by these findings. Measurements of enzyme activities of mitochondorial respiratory chain proved deficiency of ComplexⅠ in the liver and in the skeletal muscle, as well as deficiencies of ComplexⅠ and Ⅳ in the cardiac muscle, by which the diagnosis of mitochondrial disease was made. Histological tests eventually revealed the diagnosis of hcCMP in this case, which was compromised by the transition from left ventricular non-compaction to hypertrophic cardiomyopathy. The biochemical and the histological examination were useful for proper diagnosis for the metabolic disorder of this case.