Perivascular hyaline fibrosis and cell degeneration can mimic amyloid but these tumors are Congo red negative Am J Surg Pathol ; Comment Here Reference: Congo red. Sign up for our Email Newsletters. Click here for information on linking to our website or using our content or images. Home About Us Advertise Amazon. Telephone: ; Email: CommentsPathout gmail.
This website is intended for pathologists and laboratory personnel but not for patients. We welcome suggestions or questions about using the website. However, we cannot answer medical or research questions or give advice. Staining Interpretation. Control Tissue Freshly cut sections containing amyloid. Cut sections microns to show smaller amyloid deposits. Publishing research using ab? Please let us know so that we can cite the reference in this datasheet.
Hum Pathol. PMID: Chef Boyardaniel. Fabry EM. Arkana Announcement Posted September 1st The orientation of the Congo red stained amyloid fibrils in relation to the plane of the light path can alter detection. Figure 4 shows samples imaged, then re-imaged after rotating the stage. It is evident that the apple green birefringence can be seen only at one angle.
This highlights the need to use a mechanical circular stage, not found on clinical microscopes. The green birefringence is no longer visible as indicated by the arrows.
A common clinical analyzer has a polarizing filter with a built-in compensator which usually adds color and is often used for crystal examination. The use of such an analyzer in examining Congo red stained specimens, frequently leads to a field that is excessively bright and sometimes forces the observer to partially uncross the analyzer in order to accentuate the apple green birefringence. However, this results in appearance or enhancement of a bluish-green hue Fig.
Congo red stained slide images using standard microscope with an analyzer that has a build-in compensator. Blue hue black arrows compared to apple green frame arrows. Sometimes this is caused by partial uncrossing of an analyzer with built in compensator. In this report, we show that suitable microscopy equipment can increase the sensitivity of identifying the amyloid-specific birefringence in Congo red-stained tissue sections. Early diagnosis of systemic amyloidosis is essential to reducing morbidity and mortality of the disease.
Despite the seriousness of the disease and the benefit of early detection, an accurate pathologic diagnosis is still challenging. Spotty nature of disease, variation in organ-to-organ of the density of amyloid deposits, and the difficult of reproducible tissue staining, all increase the odds of false negative and false positive results. A negative tissue pathology report can effectively exclude the diagnosis of amyloidosis, which is then frequently never reconsidered among differential.
The standard of care for multiple myeloma, mono, and polyclonal gammopathy is conservative follow up, unless there is identifiable end-organ damage or amyloidosis [ 18 ].
Accordingly, missing an early diagnosis of amyloidosis can deprive a patient from receiving lifesaving treatment and can lead to costly and sometimes invasive investigations to pursue alternative diagnoses. In the case of transthyretin or fibrinogen amyloidosis, early liver transplantation usually arrests disease progression and can even be curative [ 19 , 20 , 21 ]. Therefore, even a marginal improvement in sensitivity of detection of amyloid in tissue specimens will help in assuring that patients with this serious and frequently fatal disease can be treated promptly and receive accurate prognostic information.
The real prevalence of amyloidosis is not known. The prevalence of multiple myeloma is dwarfed by the prevalence of monoclonal gammopathy, which can be as high as 8.
When the diagnosis is missed discipline-specific bias leads to ascribing to organ dysfunction to diabetes in case of renal disease and neuropathy and cardiac symptoms on hypertension or ischemia.
Yet, there is no systematic data that examine the accuracy of these presumptive etiologies, and it is not inconceivable that some fraction of these patients may be incorrectly classified. Owing to the patchy nature of amyloidosis, especially during its early stages, amyloid deposition could be restricted to just a small area of the tissue biopsy only visible at a limited angle of slide viewing. Thorough examination of each section using a mechanical rotating stage to view slides at variable angles is essential to avoid missing such deposits.
We also recommend that plastic cover slips be avoided as they can interfere with the ability to perform crossed polarized light examination and reduce ability to identify subtle or low density amyloid deposits. Low density deposits are enough to make the diagnosis due to the patchy nature of the disease. When a sample is deemed negative or equivocal, there is a need to follow previous published modifications like the use of polar mounting media or omitting the alcohol differentiation step when examining collagen rich tissue to avoid interference [ 26 , 27 , 28 , 29 ].
Finally, the use of proper optics like those of a metallurgical microscope is essential to avoid missing the presence of small deposits of amyloid in Congo red-stained tissue. There is variability on the reporting of Congo red stained slides between different labs and pathologists. We identified important pearls that can improve the ability to identify amyloid material in Congo red stained tissues.
We found that it is critical to use microscope with proper strain free optics and avoid the use of polarizer with built-in compensator. The use of mechanical rotating stage will reduce the chance of missing subtle or low-level amyloid deposits which can only produce birefringence at specific angles. Last, plastic cover slips can lead to inability to examine the slides under crossed polarized light. Improving sensitivity of the Congo red evaluation can aid in early diagnosis of amyloid and will have tremendous impact on clinical outcome of some patients.
Kyle RA. Amyloidosis: a convoluted story. Br J Haematol. Amyloid fibril proteins and amyloidosis: chemical identification and clinical classification International Society of Amyloidosis nomenclature guidelines. Current trends in diagnosis and Management of Cardiac Amyloidosis.
Curr Probl Cardiol. Article Google Scholar. Primary systemic amyloidosis: multivariate analysis for prognostic factors in cases. Nationwide biopsy survey of renal diseases in the Czech Republic during the years J Nephrol. Amyloid neuropathies. Mt Sinai J Med. Curr Opin Neurol. Sustained improvement in cardiac function with persistent amyloid deposition in a patient with multiple myeloma-associated cardiac amyloidosis treated with bortezomib. Int J Hematol. Clin J Am Soc Nephrol. AL-amyloidosis is underdiagnosed in renal biopsies.
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