Familial amyloid polyneuropathy: report of an autopsy case with neuropathy, vitreous opacities and polycystic kidney.

A 26-year-old Italian male with an unusual form of familial amyloidosis was investigated. The present case does not seem to fit into any of the forms of familial amyloidosis known for the different combinations of organ involvement. The patient developed renal failure, vitreous opacities and a sensorimotor neuropathy with trophic changes in the lower limbs. Two sural-nerve biopsies performed 5 years from each other showed a progressive loss of nerve fibers and amyloid deposits in the endoneurium. The autopsy revealed bilateral adult congenital polycystic kidney with wide deposition of amyloid in the interstitium and in the glomerular tufts. Amyloid deposits were also seen in the vitreous and in the cranial nerves. As in the other forms of familial amyloidosis, potassium permanganate treatment did not modify the Congo red affinity of amyloid deposits and immunocytochemical studies revealed that the amyloid reacted with antibodies against prealbumin.