Carcinoma cuniculatum

What is carcinoma cuniculatum?

Carcinoma cuniculatum is a rare, slow-growing variant of cutaneous squamous cell carcinoma (SCC). It tends to affect the sole of the foot, but it can occur at other sites, such as the oral cavity and genitals.

Carcinoma cuniculatum is also known as:

• Epithelioma cuniculatum
• Ackerman tumour
• Verrucous carcinoma
• Buschke–Löwenstein tumour
• Cutis papillomatosis carcinoides of Gottron.

Carcinoma cuniculatum 

Who gets carcinoma cuniculatum?

Risk factors for carcinoma cuniculatum include viral warts due to human papillomavirus infection (HPV), tobacco (smoking or snuff), chemical mutagens, and in the vulva, lichen sclerosus [1]. The genital variant tends to affect older people.

What causes carcinoma cuniculatum?

The above risk factors give rise to a variant of low–grade SCC. The genetic factors are unknown.

What are the clinical features of carcinoma cuniculatum?

Carcinoma cuniculatum is a solitary, slow growing, warty, papillomatous plaque.

• It usually develops on the foot, oral cavity, nails, or genitals.
• It rarely ulcerates.
• When located on the foot, lesions are usually found on the sole of the foot (53%), toes (21%), or heel (16%) [2].
• On the penis, it accounts for < 1% of all SCC variants.
• In the oral cavity, it can appear as a warty white neoplasm [3].

What are the complications of carcinoma cuniculatum?

In rare cases, carcinoma cuniculatum can metastasise.

How is carcinoma cuniculatum diagnosed?

Although the diagnosis of carcinoma cuniculatum may be suspected clinically, biopsy is essential to confirm the diagnosis.

What is the differential diagnosis for carcinoma cuniculatum?

The differential diagnosis for carcinoma may include:

• Cutaneous SCC — note that carcinoma cuniculatum rarely ulcerates whereas SCC commonly does
• Viral wart — however, warts are smaller than carcinoma cuniculatum and do not ulcerate.

What is the treatment for carcinoma cuniculatum?

Carcinoma cuniculatum is usually treated by surgical excision. Oral retinoids, methotrexate, laser surgery, and topical imiquimod have been reported to be effective where surgery is contraindicated [2,3].

Radiotherapy is to be avoided, as this can trigger the development of an anaplastic form of SCC.

What is the outcome for carcinoma cuniculatum?

The prognosis of carcinoma cuniculatum is very good if treated with surgical excision. Distant or local lymph node metastases are rare.