Basal cell carcinoma (BCC) is the most frequently occurring type of skin cancer worldwide. Accounting for approximately seventy percent of all skin cancers, this malignancy originates from cells in the basal layer of the epidermis. Although it is generally considered to carry a favorable prognosis due to its slow growth and rare tendency to metastasize, early diagnosis and appropriate treatment remain critically important.
What Is Basal Cell Carcinoma?
Basal cell carcinoma is a malignant tumor that develops from basal cells in the deepest layer of the epidermis, the outermost layer of the skin. It typically arises in areas most exposed to sunlight. The face, neck, ears, and scalp are the most commonly affected anatomical sites. The disease tends toward local invasion, whereas distant organ metastasis is exceedingly rare.
Risk Factors
Numerous risk factors have been identified in the development of basal cell carcinoma. Chronic and cumulative exposure to ultraviolet (UV) radiation is the most significant contributor. Risk increases markedly in individuals with fair skin, light-colored eyes, and red or blond hair. Severe sunburns during childhood, long-term use of immunosuppressive therapy, and a family history of skin cancer are among the other major risk factors.
A history of radiation exposure, contact with environmental toxins such as arsenic, and certain genetic syndromes can also elevate risk. Nevoid basal cell carcinoma syndrome, known as Gorlin syndrome, is a rare genetic condition that leads to the development of numerous BCCs at a young age.
Clinical Presentation and Subtypes
Basal cell carcinoma can present with varied clinical appearances. The most common subtype, nodular BCC, manifests as a shiny, pearlescent nodule with overlying telangiectasias. Superficial BCC is seen more frequently on the trunk and appears as a reddish, slightly raised, scaly plaque.
Morpheaform (sclerosing) BCC, with its scar-like appearance, is the most difficult subtype to recognize. It presents as a poorly defined, firm, whitish plaque and may follow an aggressive clinical course. Pigmented BCC contains dark pigmentation and can be confused with melanoma.
Warning signs patients should watch for include: non-healing sores, lesions that bleed or crust repeatedly, shiny or translucent-appearing bumps, and nodules with a central depression.
Diagnostic Methods
Clinical examination is the first step in diagnosis. Dermoscopy is an important adjunct tool for evaluating the structural features of a lesion. Definitive diagnosis is established by biopsy. A punch biopsy or excisional biopsy provides tissue for histopathological examination.
Treatment Approaches
Treatment selection is determined by the tumor's subtype, size, location, and the patient's overall condition. Surgical excision is the most widely used treatment method. Mohs micrographic surgery is preferred especially for tumors in the facial region due to its tissue-sparing advantage.
Curettage and electrodesiccation can be applied for low-risk lesions. Cryotherapy, topical pharmacological therapies, and photodynamic therapy are alternative options for superficial subtypes. In advanced cases, targeted therapies such as hedgehog signaling pathway inhibitors are employed.
Prevention and Follow-Up
Sun protection is the most effective preventive strategy. Use of broad-spectrum sunscreen, choosing protective clothing, and avoiding direct sunlight particularly during midday hours are recommended. Regular dermatological follow-up is of great importance for patients diagnosed with BCC, as the risk of developing new lesions is significantly higher than in the general population.