Basal cell carcinoma rodent ulcer

Basal Cell Carcinoma ((Rodent Ulcer):


● It is locally aggressive cutaneous tumor associated with mutations that activate the Hedgehog pathway signaling.

■ It is most common invasive skin cancer in human being.

■ Most common site (90%) is face (usually above a line from the lobe of the ear to the corner of the mouth).

■ They are slow growing and rarely metastasize.

■ Risk factors include chronic sun exposure, fair complexion, immunosuppression, and defects in DNA repair (xeroderma pigmentosum).

■ Nevoid basal cell carcinoma syndrome (NBCCS or Gorlin syndrome) :

> It is a rare autosomal dominant disorder.

> Due to mutation in PTCH gene on chromosome 9q22 which encodes the receptor for the sonic hedgehog gene (SHH) gene product.

> Characterized by multiple basal cell carcinomas occurring before 20 years of age.

> Patients also develop medulloblastomas, ovarian fibromas, odontogenic keratocysts, and pits of the palms and soles.

■ Tumors typically present as pearly papules, often with prominent telangiectatic vessels; some are melanin-pigmented.

■ Advanced lesions ulcerate and can show extensive local invasion, hence the term rodent ulcer.

■ Microscopically, most characteristic feature is the proliferation of basaloid cells (resembling basal layer of epidermis)

■ The cells at the periphery of the tumor cell islands tend to be arranged radially with their long axes in parallel alignment (palisading).