Localized amyloidosis and extramedullary plasmacytoma involving the larynxof a child

Extramedullary plasmacytoma of the larynx and localized laryngeal amyloidos is are 2 uncommon disease entities that are exceedingly rare in children. W e report a case of a 12-year-old girl presenting with progressive hoarsenes s who was subsequently found to have extramedullary plasmacytoma coexisting with localized amyloidosis involving the larynx. Results from the immunohi stochemical and molecular studies showed that the tumor cells of the plasma cytoma were monoclonal (kappa-restricted), strongly supporting their neopla stic nature, The biochemical nature of the amyloid deposits was also shown to be of kappa immunoglobulin light chain, suggesting the pathogenetic rela tionship between the plasmacytoma and amyloid deposition in the larynx of t his patient. There was no other evidence of malignancy or amyloidosis elsew here. On a follow up period of 4 years, this patient was well and asymptoma tic. We believe that this represents the first case in the literature showi ng the coexistence of extramedullary plasmacytoma and localized amyloidosis of the larynx in children. This case also supports the concept that locali zed laryngeal amyloidosis may be a manifestation of low-grade B-cell neopla sms. Copyright (C) 2001 by W.B. Saunders Company.