Amyloid nephropathy of Ostertag with special reference to renal glomerular giant cells

The pathology of an unusual form of nonneuropathic familial amyloidosis is presented. The disease, occurring in two sisters, is similar to a form of familial amyloidosis described by Ostertag in 1950 and is characterized by progressive renal failure and an autosomal dominant mode of inheritance. Widespread vascular amyloidosis and dense renal glomerular amyloid deposits characterize the disease pathologically. Renal interstitial foam cells and glomerular giant cells were found in the kidneys of one sister. The giant cells, probably of macrophage origin, contain amyloid fibrils within poorly formed non-membrane-bounded cytoplasmic vacuoles. Transitions to well-formed membrane-bounded cytoplasmic vacuoles with nonfibrillar material were also present. It is suggested that these cells function to degrade and resorb amyloid, and that as amyloid is changed to a nonfibrillar state, well-defined membranes can form around the degraded material.