Cutaneous verrucuous carcinoma

Verrucuous carcinoma may arise in the skin, the oral cavity and the genitalia. In this blog only cutaneous tumors are described. Oral & genital tumors will be discussed in separate blogs.

Clinical features

•Predilection for middle-aged males but either sex may be affected at any age including exceptionally in children

•Sole of the foot, wrists, fingers & a wide variety of other sites

•Warty lesions with conspicuous keratin-filled sinuses (carcinoma cunniculatum due to its resemblance to a rabbit warren; Latin cunniculus- rabbit, warren)

•Exceedingly high recurrence rate (due to difficulties in achieving complete excision)

•Very exceptional documentation of metastatic spread

Deeply penetrating tumor which has extended through the bone.

Very rare example in which metastases developed. Primary tumor shown above. This is the only example that I have encountered.

Histoloigcal features

•HPV implicated in cutaneous lesion & chronic scarring

•Often massive hyperkeratosis

•Epidermal verrucous hyperplasia

•Deeply penetrating bulbous processes with a pushing rather than infiltrating lower border

•Well differentiated epithelium characteristically having a ground glass appearance

•Marked tumor necrosis

•Intraepithelial abscesses

•Basally located mitoses

•Overexpression of p53 & cyclin D1 reported

Characteristic ground-glass cytoplasm

Differential diagnosis

Verrucuous carcinoma must be distinguished from a viral wart, pseudoepitheliomatous hyperplasia and well differentiated squamous carcinoma. This can be very difficult if only superficial biopsies are available for study. Distinction from a plantar wart is sometimes very problematical since some verrucous carcinomas are associated with HPV infection. Well differentiated squamous carcinoma has an infiltrating rather than a pushing lower border. Clinicopathological correlation is essential in problematical cases.