Pathogenesis of Amyloid Lymphadenopathy: In cases of amyloidosis, lymph node involvement is independent of amyloid deposition in other tissues. Lymph nodes draining heavily affected organs may show no amyloid deposits. Proteinaceous material formed as by-products of immune reactions may accumulate in lymph nodes (secondary amyloidosis) in conditions such as rheumatoid arthritis, follicular lymphoma, Hodgkin disease, plasmacytoid lymphoma, and Kikuchi disease in AIDS patients. Most of these patients have hypergammaglobulinemia with elevated levels of IgM or IgA. The proteinaceous deposits in such cases are related to amyloid but distinct biochemically and ultrastructurally. The histologic appearance is identical regardless of the type of material deposited. About this image: Acellular, amorphous, eosinophilic amyloid deposits accounted for approximately 90% of the nodal volume. The residual lymphoid tissue was benign with small but well-formed germinal centers. Foreign body giant cells surround many of the amyloid deposits. Image courtesy of : Ed Uthman, MD, Houston, Texas. Used with permission.