December 8, 2020
Diagnose This (December 7, 2020)
What would be your leading Dx and subtype based on the Congo red image above showing deposition predominately in the cortex of a Hispanic patient?
Answer: The light microscopic image depicts a positive Congo red stain compatible with Amyloidosis. The amyloid deposition was contained to the cortex and was predominately within the interstitium with minimal glomerular involvement. The leading subtype with this type of deposition in a Hispanic patient would be LECT-2 amyloid. A LECT-2 stain was performed on this case and was positive. Of note, LECT-2 is the third most common form of amyloid behind AL and AA types in a case series by Larsen et al (see reference) and is not associated with an underlying lymphoproliferative disorder or chronic inflammation.
Larsen CP, Kossmann RJ, et. al. Clinical, Morphologic, and Genetic Features of Renal Leukocyte Chemotactic Factor 2 Amyloidosis Kidney Int. 2014 (2):378-82.