Peripheral neuropathy in oxalosis. A case report with electron microscopic observations

A 61 year old man had chronic renal failure because of oxaluria and renal calculi. Two years before death, while on hemodialysis, he developed severe progressive peripheral neuropathy. At autopsy calcium oxalate crystals were found in the peripheral nerves and other tissues. Nerve lesions included segmental demyelination, axonal degeneration and crystalline deposits within the myelin sheath. Ultrastructurally there were foci of osmiophilic granular material within myelin lamellae and endoneurium, and pleomorphic lamellar bodies in the perinuclear Schwann cell cytoplasm. It is probable that chronic hemodialysis favors the deposition of oxalate in the Schwann cells and the development of neuropathy in patients with primary hyperoxaluria and renal failure.