Keratoacanthoma. A clinical study.

Keratoacanthoma (KA) is a relatively common tumor believed to be a benign epidermal neoplasm. Ninety patients with one or more KAs were observed in regard to clinical, therapeutic, and prognostic implications. In particular, we were able to analyze the relationship of KA to internal malignant neoplasms in 78 patients. Keratoacanthoma is a disease of the elderly (mean patient age, 64.1 years). It is associated with other nonmelanoma cutaneous neoplasias in 21% of cases, a figure lower than that seen with squamous cell carcinomas. When solitary, KA is not associated with concurrent or subsequent internal malignant neoplasms more often than would be predicted by population statistics. Therapy is generally curative, but about 8% of the patients had recurrences. These patients may be successfully treated with several existing modalities.