Section 14.3: Skin Neoplasms & Burn Management

Why This Matters for the PANCE

The recognition of neoplastic skin lesions and the management of acute burns are highly tested clinical concepts on the PANCE. Clinicians must quickly differentiate benign lesions from basal cell carcinoma, squamous cell carcinoma, and malignant melanoma, select appropriate biopsy techniques, and execute acute burn resuscitation protocols.

Basal Cell Carcinoma (BCC)

Basal cell carcinoma is the most common skin cancer worldwide.

• Pathophysiology and Risk Factors: BCC arises from cells in the basal layer of the epidermis, driven by intense, intermittent ultraviolet (UV) radiation. It is slow-growing, locally invasive, and destructive to surrounding tissue ('rodent ulcer') but has an extremely low rate of metastasis (<0.1%).
• Clinical Presentation: Presents as a nodular lesion (pearly, translucent papule with rolled borders and overlying telangiectasias that bleeds easily) or a superficial lesion (erythematous, scaly plaque).
• Clinical Management: Standard surgical excision (4 mm margins) is first-line for low-risk trunk/extremity lesions. Mohs micrographic surgery is indicated for high-risk cosmetic or functional areas (face, nose, ears, scalp, hands, feet) to maximize tissue preservation and cure rates.

Squamous Cell Carcinoma (SCC)

Squamous cell carcinoma is the second most common skin malignancy.

• Pathophysiology and Risk Factors: SCC arises from atypical epidermal keratinocytes and is linked to cumulative lifetime UV radiation. Risk factors include chronic immunosuppression (e.g., organ transplant recipients), chemical exposure, and chronic wounds or burn scars (Marjolin ulcer). SCC has a higher rate of metastasis (2-5%) than BCC, especially when located on the lower lip or ear.
• Clinical Presentation: Presents as a firm, erythematous, hyperkeratotic nodule or plaque with a rough, scaly surface that frequently ulcerates and bleeds easily.
• Precursor Lesion: Actinic keratosis (AK) is a gritty, 'sandpaper-like' premalignant papule treated with cryotherapy or topical 5-fluorouracil (5-FU) field therapy.
• Clinical Management: Wide local surgical excision (4-6 mm margins) is first-line. Mohs micrographic surgery is preferred for high-risk lesions or facial locations.

Malignant Melanoma

Malignant melanoma is a highly aggressive tumor arising from melanocytes. It is the leading cause of death from skin disease.

• Clinical Recognition (The ABCDE Criteria): Asymmetry, Border irregularity, Color variation, Diameter (>6 mm), and Evolving (most sensitive sign of malignancy).
• Diagnostic Workup: Suspected melanoma requires a complete excisional biopsy with narrow margins (1-3 mm) extending to the subcutaneous tissue. Shave biopsy is contraindicated as it may slice through the lesion and prevent accurate Breslow depth measurement.
• Prognosis and Staging: Breslow Thickness (vertical depth in millimeters) is the single most important prognostic factor. Sentinel lymph node biopsy (SLNB) is indicated for thickness >=0.8 mm or with ulceration, evaluating for occult regional lymph node metastasis.
• Clinical Management: Wide local excision with margins determined by Breslow thickness (ranging from 0.5-1 cm for melanoma in situ to 2 cm for tumors >2 mm thick). Systemic immunotherapy (e.g., pembrolizumab) is used for advanced stage disease.

Burn Management

Burn assessment and fluid resuscitation are critical, life-saving competencies.

• Classification of Burn Depth:
  • Superficial (1st degree): Epidermis only (e.g., sunburn). Red, dry, painful, blanching. No blisters.
  • Superficial Partial-Thickness (2nd degree): Epidermis and papillary dermis. Red, wet/weeping, blisters, extremely painful, blanching.
  • Deep Partial-Thickness (2nd degree): Epidermis and reticular dermis. Yellow/white, dry, variable pain (reduced sensation), non-blanching.
  • Full-Thickness (3rd degree): Entire dermis. Waxy white, brown, or leathery black. Dry and completely painless (nerves destroyed). Non-blanching.
  • 4th Degree: Extends to subcutaneous tissue, muscle, fascia, and bone. Charred, painless.
• Rule of Nines (Adults): Head and Neck (9%), Each Upper Extremity (9%), Anterior Trunk (18%), Posterior Trunk (18%), Each Lower Extremity (18%), Perineum/Genitalia (1%).
• Fluid Resuscitation (The Parkland Formula): Indicated for partial- and full-thickness burns involving >=15-20% TBSA.
  • Formula: 4 mL x Weight (kg) x % TBSA Burned (excluding 1st-degree burns).
  • Administration: Give 50% of the calculated volume within the first 8 hours from the time of injury (not arrival). The remaining 50% is infused over the next 16 hours. Use Lactated Ringer's.
  • Monitoring: Urine output is the gold standard for adequacy. The goal is 0.5 to 1.0 mL/kg/hour in adults (30-50 mL/hour).

Skin Neoplasms and Burn Classifications Table

Classic PANCE Traps and Clinical Pearls

• Avoid Shave Biopsy for Melanoma: Excisional biopsy with 1-3 mm margins is required, NOT a shave biopsy, which can shear the specimen and make Breslow thickness unmeasurable.
• The Parkland Time Trap: Give half of the fluid within 8 hours from the time the burn occurred, not from when the patient arrived at the emergency department.
• Exclude 1st Degree Burns from Fluid Calculations: Sunburns (erythema without blisters) do not cause the systemic capillary leak associated with deeper burns. Do not include superficial (1st degree) burns when calculating the % TBSA.