Basal cell carcinoma (BCC) is a common, locally invasive, keratinocyte cancer (also known as nonmelanoma cancer). It is the most common form of skin cancer. BCC is also known as rodent ulcer and basalioma. Patients with BCC often develop multiple primarytumours over time.
Who gets basal cell carcinoma?
Risk factors for BCC include:
Age and sex: BCCs are particularly prevalent in elderly males. However, they also affect females and younger adults
Other risk factors include ionising radiation, exposure to arsenic, immune suppression due to disease or medicines, and use of some other medicines such as hydrochlorothiazide.
What causes basal cell carcinoma?
The cause of BCC is multifactorial.
Most often, there are DNAmutations in the patched (PTCH) tumour suppressor gene, part of hedgehog signalling pathway.
These may be triggered by exposure to ultraviolet radiation.
Various spontaneous and inherited gene defectspredispose to BCC.
What are the clinical features of basal cell carcinoma?
BCC is a locally invasive skin tumour. The main characteristics are:
Slowly growing plaque or nodule
Skin coloured, pink or pigmented
Varies in size from a few millimetres to several centimetres in diameter
Spontaneous bleeding or ulceration.
BCC is very rarely a threat to life. A tiny proportion of BCCs grow rapidly, invade deeply, and/or metastasise to local lymph nodes.
Types of basal cell carcinoma
There are several distinct clinical types of BCC, and over 20 histological growth patterns of BCC.
Nodular BCC
Most common type of facial BCC
Shiny or pearly nodule with a smooth surface
May have central depression or ulceration, so its edges appear rolled
Blood vessels cross its surface
Cystic variant is soft, with jelly-like contents
Micronodular, microcystic and infiltrative types are potentially aggressive subtypes
Also known as nodulocystic carcinoma
Nodular basal cell carcinoma
Nodular basal cell carcinoma
Nodular basal cell carcinoma
Nodular basal cell carcinoma
Superficial BCC
Most common type in younger adults
Most common type on upper trunk and shoulders
Slightly scaly, irregular plaque
Thin, translucent rolled border
Multiple microerosions
Basal cell carcinoma
Superficial basal cell carcinoma
Superficial basal cell carcinoma, face
Superficial basal cell carcinoma, back
Morphoeic BCC
Usually found in mid-facial sites
Waxy, scar-like plaque with indistinct borders
Wide and deep subclinical extension
May infiltrate cutaneous nerves (perineural spread)
Also known as morpheic, morphoeiform or sclerosing BCC
Morphoeic basal cell carcinoma
Morphoeic basal cell carcinoma
Morphoeic basal cell carcinoma
Morphoeic basal cell carcinoma
Basosquamous carcinoma
Mixed basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)
Infiltrative growth pattern
Potentially more aggressive than other forms of BCC
Also known as basosquamous carcinoma and mixed basal-squamous cell carcinoma
Some typical superficial BCCs on trunk and limbs are clinically diagnosed and have non-surgical treatment without histology.
What is the treatment for primary basal cell carcinoma?
The treatment for a BCC depends on its type, size and location, the number to be treated, patient factors, and the preference or expertise of the doctor. Most BCCs are treated surgically. Long-term follow-up is recommended to check for new lesions and recurrence; the latter may be unnecessary if histology has reported wide clear margins.
Excision biopsy
Excision means the lesion is cut out and the skin stitched up.
Most appropriate treatment for nodular, infiltrative and morphoeic BCCs.
Should include 3 to 5 mm margin of normal skin around the tumour.
Very large lesions may require flap or skin graft to repair the defect.
Pathologist will report deep and lateral margins.
Further surgery is recommended for lesions that are incompletely excised.
Targeted therapy refers to the hedgehog signalling pathway inhibitors, vismodegib and sonidegib. These drugs have some important risks and side effects.
How can basal cell carcinoma be prevented?
The most important way to prevent BCC is to avoid sunburn. This is especially important in childhood and early life. Fair skinned individuals and those with a personal or family history of BCC should protect their skin from sun exposure daily, year-round and lifelong.
Stay indoors or under the shade in the middle of the day.
Oral nicotinamide (vitamin B3) in a dose of 500 mg twice daily may reduce the number and severity of BCCs.
What is the outlook for basal cell carcinoma?
Most BCCs are cured by treatment. Cure is most likely if treatment is undertaken when the lesion is small.
About 50% of people with BCC develop a second one within 3 years of the first. They are also at increased risk of other skin cancers, especially melanoma. Regular self-skin examinations and long-term annual skin checks by an experienced health professional are recommended.
Kim JY, Kozlow JH, Mittal B, Moyer J, Olencki T, Rodgers P. Guidelines of care for the management of basal cell carcinoma. J Am Acad Dermatol. 2018 Mar;78(3):540–59. doi: 10.1016/j.jaad.2017.10.006. PubMed
Loranger N, Mirza FN, Lee T, et al. Combined topical 5-fluorouracil and calcipotriene effectively treats superficial keratinocyte carcinomas: A retrospective cohort study from 2 academic centers. J Am Acad Dermatol. 2025;92(3):610-612. Pubmed