The etiology of Warthin's tumor was sought
by histochemical and immunohistochemical methods
using 7 surgically extirpated samples and normal salivary
glands as a control for the epithelial component. All the
samples exhibited a variety of amyloid deposition in the
interfollicular area of the lymphoid component. The
interfollicular lymphoid cells were both T-cells and cells
of B-cell lineage with an almost l to 2 population ratio.
Most antigen-positive B-cells were plasma cells that
exhibited polyclonality of irnmunoglobulin. B-cells were
also present in the lymphoid mantles and a few were
found in the germinal centres. The epithelial component
exhibited mucinous and proteinaceous fluid in the
lumen and varied immunohistological reactions; being
particularly positive to carcinoembryonic antigen, S-100
protein, and B-cell antigen; quite similar to that of
normal salivary duct cells. The results suggest that
Warthin's tumor may not be a hamartomatous neoplasm
at all but a hamartomatous dysplastic lesion