Verrucous carcinoma of the skin and mucosa.

The concept of verrucous carcinoma as a clinicopathologic variant of squamous cell carcinoma is worthy of recognition. It is known by a confusing array of names, such as Ackerman's tumor, Buschke-Loewenstein tumor, florid oral papillomatosis, epithelioma cuniculatum, carcinoma cuniculatum, and cutis papillomatosis carcinoides of Gottron. Its apparent clinical benignity may lead to lengthy periods of misdiagnosis, during which it is likely not to spread to distant lymph nodes, but rather to destroy a nose, mandible, or penis as it slowly but relentlessly extends into underlying tissue. Morphologically warty or verrucous, its relatively bland histologic features are often more suggestive of a verruca vulgaris or pseudoepitheliomatous hyperplasia than of squamous cell carcinoma to those unfamiliar with the diagnosis. Alternatively, when it extends into underlying tissues, it may be mistaken histologically for a benign adnexal tumor or even an epidermoid cyst. Therapy may also be challenging because recurrences are common and concerns about potential anaplastic transformation after radiotherapy are often expressed.