Basal cell carcinoma (BCC) is the common-most form of skin cancer. It is also one of the NMSC (non-melanoma skin cancers) resulting from DNA damage and mutations in the skin’s basal keratinocytes. The common name for BCC is rodent ulcer.
What is basal cell carcinoma?
Basal cells are one of the three main types of cells found in the top layer of skin. The most common reason for BCC is exposure to ultraviolet (UV) radiation, which could be from sun exposure or tanning beds.
Exposure to UV radiation causes damage to the DNA, triggering changes in the basal cells that result in uncontrolled growth.
BCC is not deadly skin cancer and seldom metastasizes (spreads) or results in death. However, it can cause local invasion, requiring extensive local surgery to remove it, resulting in significant morbidity. It is best treated quickly and efficiently to avoid deforming surgery.
Who gets basal cell carcinoma?
The risk factors for getting BCC includes:
- Age and sex. BCCs are more prevalent in elderly males
- Genetic predispositions
- Fair skin, blond or red hair, and freckles that burn easily in the sun
- Excessive sun exposure, i.e. severe sunburns in childhood or throughout life
- Use of tanning beds
- Exposure to Ionizing radiation
- Inherited genetic syndromes such as Xeroderma pigmentosum, Nevoid basal cell carcinoma syndrome, Bazex and Rombo syndromes
- Individuals with nevus sebaceous (a rare type of birthmark)
- Individuals with previous BCC or other forms of skin cancer
What does BCC look like?
Basal cell carcinoma is usually a slow-growing patch or nodule on sun-exposed areas but can occur anywhere. As there are different types of BCC, they vary in appearance:
- Superficial BCC. A pink, scaling patch of skin with a pearly appearance sometimes. It may also be pigmented (pigmented superficial BCC). They are found mainly on the trunk and extremities, and there could be multiple present.
- Nodular BCC. A pearly or opalescent nodule with branched blood vessels over the surface. These account for 50% of all BCC. They may enlarge and ulcerate.
- Micronodular BCC. These are worse than nodular BCC in that they are locally destructive and grow under the skin’s surface. The recurrence of micronodular BCC is higher.
- Morpheaform BCC. These appear as indented scars with a waxy appearance. This form of BCC is the least common but is the worst subtype.
- Ulcerative BCC. Appear as an ulcer with a pearly, white border. They are usually nodular BCC that grew and ulcerated.
- Basosquamous BCC. These have the worst prognosis since behaviour is similar to that of an SCC. They can metastasize and recur and account for 1% of all non-melanoma skin cancers.
How are BCC diagnosed?
Basal cell carcinoma is diagnosed clinically using dermoscopy to examine the close-up appearance. A biopsy and histology may be done to confirm the diagnosis.
Is there a treatment for BCC?
The treatment for BCC depends on the variation.
- Cryotherapy (freezing small lesions with the use of liquid nitrogen)
- Topical imiquimod
- Topical 5 fluorouracil
- Two photodynamic therapy sessions (light treatments using a topical photosensitiser), one week apart.
- Curette (scrape) and cautery in suitable areas
- Surgical excision
- Mohs surgery (a precise surgical technique used to treat skin cancer)
- Radiation for large, inoperable lesions
Why should you treat BCC?
Basal cell carcinoma can be locally destructive and invade the underlying bone, resulting in disfiguring surgery to remove it. Chronic ulcers may also be challenging to manage, and large lesions require more significant surgeries.
Most BCCs can be cured by treatment, and it is best to treat them early. About 50% of people with BCC develop a second one, usually within three years of the first one. As this puts you at an increased risk of skin cancer, self-skin examinations and annual skin checks by your dermatologist are recommended.