Nodular mediastinal amyloidosis.
A 67-year-old woman presented with supraclavicular lymphadenopathy, a large mediastinal mass, marrow plasmacytosis, and paraproteins, including free lambda light chains, in the serum and urine. Biopsies of the lesions demonstrated nodular amyloidosis, which was confirmed by ultrastructural and cytochemical analyses. Immunoperoxidase staining indicated that the amyloid was composed of lambda light chains. Nodular mediastinal amyloidosis is a rare manifestation of amyloidosis and appears to be a form of immunocytic amyloidosis.
D000368:Aged; D000686:Amyloidosis / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008206:Lymphatic Diseases / Q000473:pathology; D008477:Mediastinal Diseases / Q000473:pathology*; D008854:Microscopy, Electron; D010950:Plasma Cells / Q000473:pathology