Unreliability of the abdominal fat pad biopsy in the evaluation of nephrosis: report of 3 consecutive cases.
In the workup of unexplained nephrotic syndrome in the elderly patient, renal biopsy has shown amyloidosis to be the cause in 15-30% of the cases. Most of the cases of amyloidosis are primary and are, therefore, treatable with alkylating agents, albeit at a high level of toxicity. Abdominal fad pad biopsy has been suggested as a minimally invasive, low-cost method for diagnosing amyloidosis that is 100% specific. We report our experience with 3 consecutive cases of fat pad biopsy in the workup of unexplained nephrosis in the elderly patient: including the first false positive reported with respect to nephrotic renal disease, a false negative, and a true positive. We feel that in an elderly patient with unexplained nephrosis though the abdominal fat pad biopsy may be helpful, the patient should not be committed to a regimen with potentially very high toxicity on the basis of a positive fat pad biopsy alone. We recommend that the more invasive renal biopsy be performed should therapy with alkylating agents be contemplated.
Lipschutz
J H
JH
Department of Medicine, University of California, San Francisco 94143, USA.
Miller
T
T
Yen
T S
TS
Vartanian
R K
RK
Graber
M L
ML
Damon
L
L
D000005:Abdomen; D000273:Adipose Tissue / Q000473:pathology*; D000368:Aged; D000686:Amyloidosis / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D001706:Biopsy; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009401:Nephrosis / Q000175:diagnosis* / Q000209:etiology