Diagnosis and typing of systemic amyloidosis: The role of abdominal fat pad fine needle aspiration biopsy.
ABSTRACT Systemic amyloidosis (SA) has a broad nonspecific clinical presentation. Its diagnosis depends on identifying amyloid in tissues. Abdominal fat pad fine needle aspiration (FPFNA) has been suggested as a sensitive and specific test for diagnosing SA.
Thirty-nine FPFNA from 38 patients (16 women and 20 men, age range 40-88 years) during a 15-year period were reviewed. Smears and cell blocks were stained with Congo red (CR). A panel of antibodies (serum amyloid protein, serum amyloid A, albumin, transthyretin, kappa light chain and lambda light chain) was used on six cell blocks from five patients. The FNA findings were correlated with clinical and histological follow-up.
FPFNAs were positive, confirmed by CR in 5/39 (13%), suspicious in 1/39 (3%), negative in 28/39 (72%), and insufficient for diagnosis in 5/39 (13%) of cases. In all the positive cases, SA was confirmed within 2-16 weeks. Among the 28 negative cases, SA was diagnosed in 21, the rest were lost to follow-up. Among the insufficient cases, SA was diagnosed in four and one was lost to follow-up. Specificity was 100%, whereas sensitivity was 19%. SA typing using cell block sections was successful in three, un-interpretable in one, and negative in two cases.
FPFNA for SA is not as good as previously reported. This may be due to different practice setting, level of experience, diagnostic technique, or absence of abdominal soft tissue involvement. A negative result of FPFNA does not exclude SA. Immune phenotyping of amyloid is possible on cell block.
CytoJournal 01/2013; 10(1):18. DOI:10.4103/1742-6413.117359
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ABSTRACT: Alkaptonuria (AKU) is an inborn error of catabolism due to a deficient activity of homogentisate 1,2-dioxygenase. Patients suffer from a severe arthropathy, cardiovascular and kidney disease but other organs are affected, too. We found secondary amyloidosis as a life-threatening complication in AKU, thus opening new perspectives for its treatment. We proved that methotrexate and anti-oxidants have an excellent efficacy to inhibit the production of amyloid in AKU model chondrocytes. Owing to the progressive and intractable condition, it seems important to detect amyloid deposits at an early phase in AKU and the choice of specimens for a correct diagnosis is crucial. Ten AKU subjects were examined for amyloidosis; abdominal fat pad aspirates, labial salivary gland, cartilage and synovia specimens were analysed by CR, Th-T, IF, TEM. Amyloid was detected in only one abdominal fat pad specimen. However, all subjects demonstrated amyloid deposition in salivary glands and in other organ biopsies, indicating salivary gland as the ideal specimen for early amyloid detection in AKU. This is, at the best of our knowledge, the first report providing correct indications on the diagnosis of amyloidosis in AKU, thus offering the possibility of treatment of such co-morbidity to AKU patients. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_185.Diagnostic Pathology 09/2014; 9(1):185. DOI:10.1186/s13000-014-0185-9 · 2.41 Impact Factor
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ABSTRACT: A histologic diagnosis of amyloidosis requires acquiring tissue containing amyloid fibrils from an affected organ or alternate site. The biopsy site and staining techniques may influence testing accuracy. We present a case in which systemic amyloidosis was suspected; however, biopsies of the bone marrow, an osteosclerotic bone lesion, arterial and venous vessels, and the fat pad were all negative for the diagnostic Congo red stain. An eventual renal biopsy demonstrated AL-amyloidosis, kappa light chain associated with extensive vascular interstitial, and glomerular, involvement. Choice of biopsy site, as well as staining and analysis of the tissue, can influence sensitivity and specificity of amyloid testing. Fat-pad biopsies are less invasive and offer reasonable sensitivity. Bone marrow samples are only diagnostic up to 63% of the time. A renal biopsy offers improved sensitivity and is generally safe in experienced hands, but is a more invasive procedure with increased number of relative contraindications and complications. The choice of the biopsy site should be based on considering the expected yield, accessibility of the site, and the risks associated with the procedure.12/2012; 2012. DOI:10.1155/2012/593460