[Ackerman carcinoma of the lower extremity--course, pathology, therapy].

Two cases of verrucous carcinoma (Ackerman) of the lower extremity are reported. This is a low-grade malignant and slow-growing variant of squamous cell carcinoma. One tumor existed for at least 15 years, the other for 3 years, both without metastasizing. These cauliflower-like lesions are more exophytic than endophytic and are covered with foul-smelling keratinous material, which can also be pressed out of the crypts. On histological examination, deep invaginated epidermal proliferations can be seen, with a high degree of keratinization leading to central parakeratotic horn crypts. Only the basal and suprabasal cell layers show nuclear atypicality and loss of polarity of the basal cells, but the basal membrane is intact. The therapy of choice is local excision. The tumor must be totally removed on the first attempt. Radiation therapy and repeated operations favor anaplastic transformation and may provoke iatrogenic metastasizing.