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March 1960

Keratoacanthoma: A Review of Histopathological Specimens Previously Diagnosed as Keratoacanthoma or as Squamous Cell Carcinoma of the Skin

Author Affiliations

U.S.N.; U.S.N.; San Diego, Calif.

AMA Arch Derm. 1960;81(3):369-372. doi:10.1001/archderm.1960.03730030027003

The first report of keratoacanthoma appearing in the American literature was in 1954.1 These lesions were being reported in the European literature as early as 1950.2 In the United States, prior to 1954, these lesions were undoubtedly either classified as squamous cell carcinoma of the skin, or placed in the group entitled "Tumorlike Keratoses."3

The fact that these lesions were not reported as a definite entity in this country prior to 1954, coupled with the flood of reports in the literature4 since 1954, raises the following questions. Are we seeing a new entity? Have we always seen these lesions, but diagnosed them as other entities, such as squamous cell carcinoma of the skin? These questions could, in part, be answered by reviewing the pathological specimens of keratoacanthoma and squamous cell carcinoma of the skin during this transitional period. Hence this study.

Procedure  All available histopathological material diagnosed as keratoacanthoma and as squamous cell carcinoma of the skin at the U.S. Naval Hospital, San Diego, California, from 1951 through 1957, was reviewed. This represented 233 cases. Nineteen cases of keratoacanthoma, and 214 cases reported as squamous cell carcinoma, usually grade one, of the skin, were reviewed. After careful examination, 21 sections, previously diagnosed as squamous cell carcinoma, were considered to be keratoacanthoma. See Table 1 and Table 2 for