Amyloid in localised deposits and plasmacytomas of the respiratory tract.

Clinical and histological features of 25 cases with amyloid deposits in the respiratory tract are described. The false cord is the commonest single site of such "primary" amyloid involvement. Evidence of extensive involvement and replacement of seromucinous glands by amyloid was seen in each case. Fourteen cases of plasmacytoma with "secondary" amyloid deposits are also described. The nose and nasopharynx were principally involved as with respiratory tract plasmacytomas in general but a similar association of the amyloid with seromucinous glands was also seen. Electron microscopy showed early involvement of the basal lamina of the duct of a seromucinous gland by amyloid in one case. Possible reasons for the association of amyloid precursors in respiratory tract amyloid with seromucinous glands are given.