Basal Cell Carcinoma (BCC)

BCC is a common, locally invasive malignancy of keratinocytes that very rarely metastasizes but can cause significant local tissue destruction if neglected.

Demographics:

• Typically middle-aged or older adults (peak 40–80 years).

Ethnicity:

• Over 99% of BCCs occur in White individuals in some series. BCC is less common overall in Skin of Colour (SOC), but when it does occur, it's often diagnosed late because it doesn't fit the classic pale, pearly description. Pigmented BCC is proportionally more common in SOC (e.g., twice as common in Hispanic patients compared to White patients).

UV Exposure:

• Chronic, cumulative sun exposure and history of repeated sunburns, especially in youth. Use of sunbeds.

Other Risks:

• Previous BCC/SCC, Immunosuppression (organ transplant), arsenic exposure, and genetic syndromes (e.g., Gorlin Syndrome).

Symptom History:

• Slowly enlarging lesion over months–years. May have recurrent bleeding with minor trauma ("it scabs, heals, then bleeds again") or a non-healing ulcer/sore. Usually painless.

Distribution: 

• Favours sun-exposed sites (Face: nose, cheeks, eyelids, ears, forehead; neck, upper chest, back).

SOC Note:

• Still favors sun-exposed sites, but careful inspection of less obvious areas is vital due to delayed diagnosis

Clinical Type:

• Nodular BCC (Most common)

  • Appearance: Pink/skin-coloured, shiny ("pearly") papule/nodule with fine arborising telangiectasia. May have a central ulcer ("rodent ulcer").

  • SOC Considerations: Background erythema is subtle; lesion may look more skin-coloured or brown with a shiny surface.

• Superficial BCC

  • Appearance: Thin, scaly, pink/red patch or plaque with a raised, translucent border. Often mistaken for eczema or psoriasis.

  • SOC Considerations: Erythema is subtle; lesion may appear faintly hypopigmented or brown.

• Pigmented BCC

  • Appearance: Nodular or superficial BCC with brown, blue, grey, or black pigmentation.

  • SOC Considerations: More common in darker skin types; important differential diagnosis is melanoma. Look for arborising vessels (favours BCC).

• Morpheaform BCC (Aggressive)

  • Appearance:Scar-like, waxy, indurated plaque with ill-defined borders, often skin-coloured or yellow-pink. 

  • SOC Considerations: Subtle colour and scar-like change can be easily overlooked, leading to significant destruction. 

The primary goal is complete tumour removal while preserving function and cosmesis, especially on the face.

1. Initial Steps & Risk Stratification

• Biopsy: Essential to confirm diagnosis and determine the subtype (shave, punch, or excisional biopsy).

• Risk Stratification: Categorize as Low-Risk (small, well-defined, on trunk/limbs) or High-Risk (on central face/ears/scalp, large size, aggressive histology like morpheaform, or recurrent tumours).

2. Surgical Treatments (First-Line)

• Standard Excision: Mainstay for most BCCs. Requires a 3–5 mm margin of normal skin for low-risk tumours.

• Mohs Micrographic Surgery: Gold standard for High-Risk BCCs (face, recurrent, aggressive subtypes). It is tissue-sparing with the highest cure rates (sim 99% for primary BCC).

3. Non-Surgical Therapies

Used for superficial/low-risk lesions or for poor surgical candidates.

• Curettage & Electrodesiccation (ED&C):

  • Quick and inexpensive for low-risk nodular/superficial lesions on trunk/limbs.

  • Leaves a hypopigmented, atrophic scar, which is often very noticeable in darker skin to use cautiously.

• Cryotherapy:

  • Liquid nitrogen for small superficial BCCs.

  • Leaves a permanent hypopigmented/depigmented patch, so use cautiously due to high cosmetic impact.

• Topical Imiquimod 5% cream:

  • Immune response modifier for superficial BCCs. Causes inflammation.

  • Warn about the high risk of Post-Inflammatory Dyspigmentation (light or dark marks) following the inflammatory reaction.

• Radiotherapy:

  • Used when surgery is not feasible.

  • Can cause atrophy and dyspigmentation, which are particularly visible in darker skin.

4. Ongoing Care & Considerations for SOC

• Sun Protection: Broad-spectrum SPF 30–50 daily on exposed sites, protective clothing, and avoidance of tanning beds (essential for all skin tones).

• Follow-up: High risk of developing additional skin cancers. Regular professional skin checks (at least annually) are mandatory.

• Cosmetic Counselling (SOC): Discuss up front that scars and post-inflammatory hypo-/hyperpigmentation are often more obvious and longer-lasting. Favour techniques like Mohs or surgical closures along tension lines to optimize the scar outcome.

Skinsight – Basal Cell Carcinoma (BCC):

NCBI Bookshelf – Basal Cell Carcinoma (McDaniel & Steele, 2024)

DermNet NZ – Basal Cell Carcinoma (Oakley, 2015)