Adult onset lipid storage in gastric mucosa and skeletal muscle fibers associated with gastric pain, progressive muscle weakness and partial deficiency of cytochrome C oxidase.

We report on the first case, a 21-year-old man, with partial deficiency of cytochrome c oxidase, lipid storage myopathy and concomitant lipid storage in the gastric mucosa affecting chief, parietal, and argentaffine cells as well as interstitial macrophages. The clinical symptoms consisted of increasing muscle weakness, cramps of the legs, and severe gastric pain that was resistant to treatment. Muscle biopsy specimens showed severe lipid storage in muscle fibers. Enzyme histochemistry revealed partial deficiency of cytochrome c oxidase (COX) with scattered non-reactive fibers among a majority of COX-positive fibers whereas biochemical analysis of muscle homogenates resulted in no corresponding defect of mitochondrial enzymes. Gastric biopsy specimens showed similarly to muscle fibers an extensive accumulation of lipid droplets in the chief cells, HCl producing parietal cells, macrophages, neutrophilic and eosinophilic leucocytes, and to a lesser degree also in argentaffine cells and unmyelinated axons of the gastric mucosa. The lipid droplets were associated with an insignificant increase in the number and size of mitochondria although paracristalline mitochondrial inclusions were neither noted in muscle fibers nor in cells of the gastric mucosa. These findings resemble those in multisystem triglyceride storage disease although the clinical signs were not reminiscent of this disease, and indicate that among the clinically heterogeneous group of cytochrome c oxidase deficiencies lipid storage may not be confined to muscle, but can affect the gastric mucosa as well.