Amyloid in basal cell carcinomas.

Stromal or intratumour deposits of amyloid were found in thirty of forty-six randomly selected basal cell carcinomas. Amyloid was found less often in histologically aggressive tumours than in other sub-types. Immunoglobulins, predominantly IgM, were demonstrated in all but one of these thirty cases, corresponding to the distribution of the amyloid deposits. Electron microscopy revealed 'early' amyloid in one case which showed numerous stromal IgM bodies on immunofluorescence but no evidence of amyloid by routine histochemical methods.