Laryngeal plasmacytoma presenting as amyloid tumour: a case report.

Laryngeal amyloidosis can be secondary to an underlying lymphoid neoplastic process and in view of this concept; the cases of localized laryngeal amyloidosis should be carefully examined and investigated for the presence of a lymphomatous process. The study design is case report. We report the case of a 64-year-old man with progressive hoarseness. A biopsy showed histological findings consistent with an extramedullary plasmacytoma associated with localized amyloidosis involving the right hemilarynx (ventricular band, arytenoids and true cord). Immunohistochemical studies showed that the tumour cells of the plasmacytoma were monoclonal (lambda-restricted). PCR analysis of the IgH gene demonstrated a clonal band confirming B-cell clonality. The amyloid deposits were also shown to be reactive with lambda immunoglobulin light chain, suggesting the pathogenetic relationship between the plasmacytoma and amyloid deposition in the larynx. There was no other evidence of malignancy or amyloidosis elsewhere. The majority of the cases reported of amyloid deposition with plasmacytoma, the lesions were found in the nasopharynx, in contrast to our case in which the lesions were sited in the larynx and with the peculiarity of being multiples. Moreover, amyloid and plasmacytoma were clearly delimitated and the amyloid tissue was more extensive than the tumour tissue. This case supports the concept that localized laryngeal amyloidosis may be a manifestation of low-grade B-cell neoplasms.