To the Editor.—
Seborrheic keratoses are the most common benign neoplasms in man.1 Although true malignant transformation of these lesions has been debated, reports have been published of squamous cell carcinoma in situ or Bowen's disease, basal cell carcinoma, squamous cell carcinoma, keratoacanthoma, and malignant melanoma all arising in seborrheic keratoses.2-6 There have, however, been no previous reports of an adenocarcinoma arising in a seborrheic keratosis.
Report of a Case.—
A 66-year-old white man presented with an enlarging pigmented lesion on his right shoulder for several years; this lesion had been traumatized on several occasions. Approximately 2 months before removal of the lesion, he noticed a change in the central portion of the lesion. At the time of excision, the lesion measured 4.6 × 2.8 cm, with a thickness of 5 to 6 mm in the area of greatest thickness. In the center was an oval, moist, firm,
Smith KJ, Skelton HG, Lupton GP, Palomino NJ. Adenocarcinoma Arising in a Seborrheic Keratosis. Arch Dermatol. 1991;127(11):1738-1739. doi:10.1001/archderm.1991.01680100142033