Metastatic melanoma to the palatine tonsil with a favourable prognosis.

Metastasis to the oral cavity from cutaneous melanoma is rare: fewer than 30 cases of metastatic melanoma to the palatine tonsil have been reported. Tonsil metastasis is haematogenously disseminated and therefore usually has a poor prognosis. We present a case of metastatic melanoma to the palatine tonsil occurring 6(1/2) years after removal of the primary cutaneous lesion. The patient has remained disease-free for 18 months since the removal of skin and tonsil metastases. Immunohistopathologically, HLA class II and costimulatory factor B7-2 molecules were concomitantly expressed on melanoma cells: we suggest that the patient was therefore able to develop antimelanoma T-cell activation resulting in prevention of further metastasis, and thus a favourable prognosis.