Acantholytic acanthoma is typically an asymptomatic, keratotic papule or nodule. In 1988, Brownstein described a previously unrecognized benign acanthoma, the acantholytic acanthoma. The term acantholytic is used because acantholysis is the outstanding histologic feature in this neoplasm; acanthoma is chosen because the growths are benign tumors of epidermal keratinocytes. On histopathology, these tumors may mimic pemphigus vulgaris, pemphigus vegetans, superficial pemphigus, or Hailey-Hailey disease, but had no evidence of any of these disorders. We report a case of acantholytic acanthoma seen on the inguinal area of a 79-year-old man who had a keratotic nodule on the left inguinal area.