Prominent Features of Basal Cell Carcinoma
Basal cell carcinoma (BCC) presents with diverse clinical and histological features, with the most prominent characteristics being nodular, cystic, superficial, morpheaform (sclerosing), keratotic, and pigmented variants, which infiltrate tissues through three-dimensional subclinical finger-like outgrowths that remain contiguous with the main tumor mass. 1
Clinical Presentations
Common Clinical Variants:
- Nodular BCC: Most common form, presenting as waxy, translucent papules or nodules, often with ulceration and telangiectasia 2
- Superficial BCC: Appears as scaly, pink to red-brown patches, predominantly on the trunk 3
- Morpheaform/Sclerosing BCC: Presents as indurated, scar-like plaques with poorly defined borders
- Pigmented BCC: Contains melanin, can be confused with melanoma
- Cystic BCC: Presents with cystic components
- Keratotic BCC: Shows keratinization
Key Dermoscopic Features:
- Shiny white to red areas (100% of superficial BCCs)
- Erosions (78.6%)
- Short fine telangiectasias (66.6%)
- Leaf-like areas (16.6%)
- Arborizing telangiectasias (14.3%)
- Blue-gray globules (14.3%)
- Large blue-gray ovoid nests (4.7%) 3
Histopathological Features
Common Histological Subtypes:
- Nodular BCC: Well-circumscribed nests of basaloid cells with peripheral palisading
- Superficial BCC: Buds of basaloid cells attached to the undersurface of the epidermis
- Morpheaform/Infiltrative BCC: Thin strands of tumor cells embedded in dense fibrous stroma
- Micronodular BCC: Small tumor nests similar to nodular BCC but smaller and more widely dispersed
- Basosquamous (metatypical): Shows features of both BCC and squamous cell carcinoma 1
Aggressive Histological Features:
- Perineural invasion
- Perivascular invasion
- Infiltrative growth pattern
- Morpheaform/sclerosing pattern
- Micronodular pattern
- Basosquamous features 1
Risk Factors Influencing Prognosis
Tumor-Related Factors:
- Size: Larger tumors have higher recurrence risk
- Location: Central face, especially around eyes, nose, lips, and ears (H-zone) have higher recurrence risk
- Clinical margin definition: Poorly defined lesions have higher recurrence risk
- Histological subtype: Aggressive subtypes have higher recurrence risk
- Perineural/perivascular involvement: Higher recurrence risk
- Previous treatment failure: Recurrent lesions have higher risk of further recurrence 1
Patient-Related Factors:
- Immunosuppression
- History of radiation at the site
- Genetic predisposition (e.g., Gorlin's syndrome)
- Fair skin types I and II 1
Diagnostic Approach
Clinical Diagnosis:
- Enhanced by good lighting and magnification
- Dermatoscope may be helpful in some cases 1
Biopsy Techniques:
- Punch biopsy
- Shave biopsy
- Excisional biopsy 1
When to Biopsy:
- When clinical doubt exists
- When patients are being referred for subspecialty opinion
- When histological subtype may influence treatment selection and prognosis 1
Treatment Considerations
Treatment selection should be based on:
- Tumor size and location
- Histological subtype
- Definition of clinical margins
- Previous treatment history
- Patient factors (age, medical condition, preferences)
- Preservation of function and cosmetic outcome 1, 4
Treatment Options:
- Surgical excision: Standard for most BCCs, with 4-mm clinical margins for low-risk tumors
- Mohs micrographic surgery: Recommended for high-risk BCCs
- Curettage and electrodesiccation: May be considered for low-risk tumors in non-terminal hair-bearing locations
- Topical 5-fluorouracil: Useful for superficial BCCs when conventional methods are impractical 1, 5
Important Clinical Caveat
BCC metastasis is extremely rare, with morbidity primarily resulting from local tissue invasion and destruction, particularly on the face, head, and neck. The slow growth rate means recurrences may be diagnosed beyond 5 years following treatment, necessitating long-term follow-up 1.