Localized AL amyloidosis

Abstract

Localized light chain (AL) amyloidosis (amyloidoma) is a rare disease with unclear pathogenesis and undeveloped approaches to therapy. This article presents 3 clinical observations of localized AL amyloidosis with lesions of the respiratory tract, eyes, and soft tissues of the face. Tumor masses consisted of amyloid masses in which single monotypic plasma cells were "embedded". To verify the cell substrate, the method of chromogenic in situ hybridization with probes to immunoglobulin light chains was used. Amyloid typing was performed using FITC-labeled antibodies to kappa and lambda light chains after enzymatic treatment of paraffin sections with pronase. The absence of monoclonal secretion (in two cases) made it difficult to assess the efficacy of the therapy. Taking into account the prevalence and severity of vital organs damage, as well as the recurrent nature of the disease course, systemic combination therapy with targeted drugs was prescribed. Stabilization of the process in all patients was stated during one year of follow-up. Nevertheless, clonreducing therapy in localized AL amyloidosis is not considered as a standard option, its feasibility and efficacy requires further confirmation.

Keywords

• localized al amyloidosis
• amyloidoma