Metastases in dermatological patients with squamous cell carcinoma.

Two hundred eleven patients in whom squamous cell carcinoma (SCC) of the skin had been diagnosed between 1950 and 1959 were followed up from Jan 1, 1976, to establish the incidence of metastases. A systemic study was carried out through follow-up examinations and tracing through population registers. We found 3.3% metastases in 153 patients with skin SCC and 11% metastases in 55 patients with labial SCC. Three patients with genital SCC were free of metastases. These results and the available literature on patients with SCC of osteomyelitic foci and scars from burns or x-ray treatment indicate that sharp distinctions must be made among three groups of SCC; mucocutaneous, primary cutaneous, and cutaneous SCC secondary to inflammatory and degenerative processes. The incidence of metastases in the three groups is approximately 11%, 3%, and 10% to 30%, respectively. Percentages found are important to dermatology clinics because skin SCC should be considered a malignant tumor with a higher incidence of metastases than previously assumed.