Metastatic squamous-cell carcinomas derived from solar keratosis.

Actinic squamous-cell carcinoma has been described to have a low risk of metastasis. Reported here are four Japanese cases of lymphatic metastasis of squamous-cell carcinoma derived form solar keratosis. The primary lesions were on the face in three cases and on the back of the hand in one. Two patients died, and others had recurrent incurable metastatic lymph nodes. Therefore, it is noteworthy that actinic squamous-cell carcinoma in the Japanese can become so aggressive and metastasize.