Large cell acanthoma. One of the actinic keratoses.

Large cell acanthoma (LCA), which was first introduced to the dermatologic literature in 1970 and has had no major presentation since then, is not an uncommon lesion. The lesion is a circumscribed hyperkeratotic epidermal growth with the outstanding pathologic feature being large cells. Clinical diagnoses have included several benign and malignant skin conditions. Large cell acanthoma may be related to lichen planus-like keratosis and lentigo senilis. We diagnosed 38 instances of LCA among 34,000 specimens received in our dermatopathology laboratory.