Lymphadenopathy caused by intramuscular injections of gold and subsequent deposit in lymph nodes.

In chrysotherapy for rheumatoid arthritis, gold sodium thiomalate is injected intramuscularly over long periods of time (1,2). In one reported case, of a woman with a 33-year history of severe progressive rheumatoid arthritis and marked deformities of her hands and feet, intramuscular gold sodium thiomalate had been administered every 2 weeks for 10 years (2). Following intramuscular administration, 90% of the gold compound is bound to protein, and approximately 40% of each dose is eliminated in urine and feces (3). Gold toxicity is manifested by a number of complications, including dermatitis, thrombocytopenic purpura, nephritis, and vasculitis. Some 25% to 50% of patients must discontinue therapy because of toxicity (1,2). Lymph node complications may present as nodal infarction (4), but more commonly gold lymphadenopathy develops when gold particles are transported to the lymph nodes, where they are dispersed throughout the nodal sinuses and parenchyma. The lymph node reaction is that of foreign-body lymphadenopathy.

The lymph node follicles are enlarged, sometimes irregularly shaped and coalescing. The germinal centers are reactive and contain tingible-body macrophages (2). The sinuses are dilated and filled with histiocytes. Foreign material, in the form of black or colorless, round or rectangular plate-like crystalline structures, is dispersed throughout the sinuses and nodal parenchyma, more often within the cytoplasm of multinucleated giant cells and histiocytes (1,2). The foreign material does not polarize (1) (Fig. 53.1).