Proteinaceous lymphadenopathy in a patient with known rheumatoid arthritis--case report and review of the literature.

We describe a case of proteinaceous lymphadenopathy (also called lymph node hyalinosis) in a 30-yr-old woman with known rheumatoid arthritis (RA). Amyloidosis was excluded by negative staining with congo red viewed with and without polarized light. Proteinaceous lymphadenopathy should be included in the differential diagnosis of patients with lymphadenopathy and long-standing RA. The histopathologist should be familiar with the morphological appearances of this condition, which can be confused with amyloidosis. It appears that there is a good clinical response in RA-associated proteinaceous lymphadenopathy following successful treatment of arthritis.