Basal Cell Carcinoma
A slow-growing, locally destructive skin cancer caused by sun exposure, typically appearing as a pearly bump on the face.
Emergency Management: Massive hemorrhage from a neglected, deeply ulcerating BCC invading a major artery (extremely rare).
Basal cell carcinoma (BCC) is the most common type of skin cancer, arising from the basal layer of the epidermis and its appendages. It is locally invasive, destructive, and slow-growing, with extremely low rates of metastasis.
Detailed Overview
BCC is primarily caused by cumulative ultraviolet (UV) light exposure, making it most common on sun-exposed areas like the head and neck. It frequently presents as a pearly papule with telangiectasias or a non-healing ulcer. While rarely fatal, untreated BCC can cause extensive localized tissue destruction and significant cosmetic deformity.
Epidemiology & Demographics
The most common malignancy in humans. Incidence increases with age. Highest prevalence in fair-skinned individuals (Fitzpatrick skin types I and II) with a history of chronic sun exposure.
Etiological Mechanism
Ultraviolet radiation (UVB > UVA) causing DNA damage and mutations in the PTCH1 gene (Hedgehog signaling pathway).
Primary Causes
Chronic and intermittent sun exposure, artificial tanning bed use, ionizing radiation, arsenic exposure.
UV radiation induces thymidine dimers and mutations in tumor suppressor genes (e.g., TP53, PTCH1). Loss of PTCH1 function leads to unregulated activation of the Hedgehog signaling pathway via SMO (Smoothened), causing uncontrolled proliferation of basal keratinocytes.
Diagnostic Criteria & Guidelines
Diagnosis requires a shave, punch, or excisional skin biopsy demonstrating basaloid tumor cells with peripheral palisading and peritumoral clefting (retraction artifact) on histopathology.
Standard surgical excision with 4-mm margins for low-risk tumors on the trunk/extremities. Mohs micrographic surgery is first-line for high-risk tumors (face, hands, large size, morpheaform subtype) to ensure 100% margin clearance while sparing healthy tissue.
Second-Line & Adjunctive Therapy
Electrodesiccation and curettage (ED&C) for small, superficial/nodular BCCs on low-risk areas. Topical 5-Fluorouracil 5% cream BID for 3-6 weeks or Imiquimod 5% cream 5 times/week for 6 weeks for superficial BCCs.
Surgical & Procedural Management
Mohs micrographic surgery: tumor excised in stages, with complete 360-degree microscopic margin control intraoperatively.
Patient Counseling & Advice
Explain that while BCC rarely spreads, it requires complete removal to prevent local destruction. Patients with one BCC have a 30-50% risk of developing another non-melanoma skin cancer within 5 years.
Follow-Up & Monitoring Schedule
Total body skin examination every 6 to 12 months by a dermatologist to screen for recurrences and new skin cancers.
Preventive Strategies
UV protection (sunscreen, hats, shade). Avoid indoor tanning beds.
Excellent. Cure rate is >99% with Mohs surgery for primary BCCs. Mortality is exceedingly rare.