Amyloid Lymphadenopathy

Comments:
Primary (AL) Amyloidosis: Amyloid derived from immunoglobulin light chains is designated AL and is subdivided into kappa and lambda types based on the isotype of light chains present. The presence of AL protein in the lymph node is suggestive of a plasma cell dyscrasia, idiopathic amyloidosis, or a lymphoproliferative neoplasm and warrants further work up.

Secondary AA Amyloidosis: A second form of amyloid composed of amyloid fibril protein AA is more often associated with secondary amyloidosis that may be seen in chronic infections and inflammatory conditions such as rheumatoid arthritis, ankylosing spondylitis, Crohn disease, tuberculosis, and osteomyelitis.

The image shows amyloid deposits that appear orange-red with Congo Red stain.

Image courtesy of : Ed Uthman, MD, Houston, Texas. Used with permission.