myeloma kidney

myeloma kidney

The combination of structural and functional renal defects seen in ±40% of myelomas–eg, intraluminal eosinophilic 'blocked pipe' casts composed of PAS—positive homogeneous material and light chains–Bence-Jones proteins within flattened distal tubules and collecting ducts–pressure atrophy, spilling over of proteinaceous material, eliciting chronic interstitial nephritis, occasionally causing glomerulonephritis; the mesangial widening may mimic diabetic nephropathy; functional abnormalities cause renal failure in 20%, due to hypercalcemia and renal calcinosis, heavy Bence-Jones proteinuria–causing tubular damage, hyperuricemia– ↑ tumor DNA turnover, proteinuria, amyloidosis, and chronic pyelonephritis, acquired Fanconi syndrome, defects in acidification and concentration, acute and chronic renal failure Lab A peak may be seen in
γ-globulin region–usually of urine electrophoresis or may appear between the α₂ and β regions