new_n_lost
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A 73-year-old woman with osteoarthritis and mild hypertension goes to her physician’s office with new-onset lower back pain and progressively worsening fatigue. Physical examination reveals normal blood pressure and pale conjunctivae. The lower lumbar spine (L4��"L5) is tender to palpation, and the ankles have 2+ pitting edema. Laboratory measurements are hemoglobin, 6.2 g/dL and serum creatinine, 4.8 mg/dL. Bone marrow biopsy results are consistent with multiple myeloma; a 24-hour urine collection shows 6.5 g of albumin and 1.2 g of monoclonal κ light chain. Renal biopsy employing light microscopy shows nodular lesions in the glomerulus. On electron microscopy, granular deposits are seen along the basement membranes and in the glomerular nodules. No fibrillar material is identified in the biopsy specimen.
Which of the following most likely caused the patient’s renal disease?
A) Hypertensive arteriolonephrosclerosis
B) Light-chain deposition disease in the kidney
C) Myeloma cast nephropathy
D) Renal amyloidosis
Edited by new_n_lost on 03/04/07 - 08:27 PM
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| me007
Forum Guru
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b and d
light chains damage the tubules and they are converted to amyloid.
Also 3rd mechanism - metastatic calcification.
But the q is about what caused - b.
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| indidoc1
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B.
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| mytime
Kick my butt!
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B
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| keepgoing
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B
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| unique1
InGodITrust
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B
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| new_n_lost
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The combination of renal insufficiency, nephritic proteinuria, and nodular glomerulosclerosis supports both light-chain deposition disease and light chain (AL) amyloidosis as the most likely renal lesions. Light-chain deposition disease is more often associated with κ light chains, while amyloidosis is associated with λ light chains. The distinguishing feature in this case is the presence of granular deposits along the basement membranes and in the glomerular nodules on electron microscopy, which support a diagnosis of light-chain deposition disease. In contrast, AL amyloidosis is characterized by fibrillar deposits (8��"10 nm in diameter) on electron microscopy. Hypertensive arteriolo-nephrosclerosis is extremely unlikely in the presence of nephritic proteinuria and the noted histologic findings. Multiple myeloma cast nephropathy is not complicated by nephrotic proteinuria, and the classic lesions seen on renal biopsy are fractured proteinacious casts in the distal tubular lumens, often associated with multinucleated giant cells
Edited by new_n_lost on 03/06/07 - 05:35 PM
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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