Amyloidosis: a rational approach to diagnosis by intraoral biopsy.

Amyloidosis and its oral manifestations are briefly described. The techniques for antemortem tissue diagnosis of amyloidosis are reviewed and evaluated. In screening for amyloidosis, biopsy of specific oral lesions (when present) is recommended instead of the traditional biopsy of normal-appearing gingiva. This approach is illustrated with four cases. Although rectal biopsy is generally accepted as the screening technique of choice, it is suggested that intraoral biopsy be considered as an easier, safer, more comfortable, and possibly more fruitful technique. It is advocated that in cases of both documented and suspected amyloidosis both intraoral and rectal biopsies should be performed in order to help provide documentation of the most useful technique for routine screening.