Polypoid basal cell carcinoma: a new clinicopathological variant.

Basal cell carcinoma (BCC), the most common malignant neoplasm of the skin, has many different clinical and histological appearances. Four patients with a new distinctive form, polypoid BCC, are described. Polypoid BCC is clinically distinguished from other types of BCC by being pedunculated and having a stalk that connects it to the skin surface. Histologically, it is distinctive in that the tumour aggregations are restricted to the exophytic polypoid zone.