Nonmelanoma skin cancer: number of cancers and their distribution in outpatients.

Background: Nonmelanoma skin cancer (NMSC) is increasing in incidence and more are developing on the trunk and limbs. The objectives were to determine how many outpatients have more than one NMSC at the time they present for treatment and to determine the anatomical distribution of the cancers.
Methods: All outpatients with histologically confirmed NMSC visited by the authors during 1992 received a total body examination and the number and sites of NMSC were recorded.
Results: A total of 952 outpatients were seen. A single NMSC was present in 69.4%, two in 16%, three in 6.4%, four in 3.5%, five to nine in 4.2%, and 0.5% had ten or more. Of the 291 patients with more than one NMSC, one anatomical region was involved in 53.4%, two were involved in 38.4%, and 8.2% had three or more regions involved.
Conclusion: Patients with NMSC required a total body examination to detect unsuspected skin cancers.