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Congo Red Elastic Lamina

Jon Wilson, MD neuropathologist at arkana laboratories
By Jon Wilson, MD

Dec 17, 2021

Figure 1: Congo Red frozen section bright field microscopy 400x original magnification

This previously healthy 30-year-old patient presented with tingling and numbness involving their extremities, followed by progressive lower extremity muscle weakness and pain. Extensive prior laboratory workup was negative for specific etiology. Electrodiagnostic studies showed evidence of an axonal distal symmetrical peripheral neuropathy.


What structure is highlighted when visualized under fluorescence microscopy?

A. Internal elastic lamina

B. Vascular amyloid

C. Micromineralization

D. Foreign material



Answer: Internal elastic lamina

Light microscopic examination demonstrates the presence of a small muscular artery. The internal elastic lamina is not well-visualized on bright-field microscopy but is nicely highlighted by non-specific staining for Congo Red when viewed with fluorescence microscopy using Texas Red and FITC filters.

No “salmon-orange” color on bright field (or “apple-green” birefringence on polarized light… not shown) is seen on bright-field microscopy to indicate the presence of amyloid type material. The material does not have the blue-crunchy appearance of micromineralization, and does not represent foreign material.


Quick note: This post is to be used for informational purposes only and does not constitute medical or health advice. Each person should consult their own doctor with respect to matters referenced. Arkana Laboratories assumes no liability for actions taken in reliance upon the information contained herein.