Pathology of the Skin: Burns and Skin Cancer

Pathology of the Skin

Classification and Severity of Burns

Burns are injuries to the skin caused by heat, chemicals, electricity, or radiation. They are classified based on their depth and the extent of tissue damage. Accurate classification is essential for determining treatment and prognosis.

• First-degree burns: Affect only the epidermis. Symptoms include redness, mild pain, and no blistering. Healing occurs within a few days without scarring.

• Second-degree burns: Involve the epidermis and part of the dermis. Symptoms include redness, pain, swelling, and blistering. Healing may take several weeks and can result in some scarring.

• Third-degree burns: Destroy both the epidermis and the entire dermis, potentially affecting underlying tissues. The area may appear white, charred, or leathery, and sensation is often lost due to nerve damage. These burns require medical intervention and often result in significant scarring.

Estimating Burn Severity: The severity of a burn is also determined by the total body surface area (TBSA) affected. The "Rule of Nines" is commonly used for adults, dividing the body into sections, each representing approximately 9% (or multiples thereof) of the TBSA.

• Mild burns: Less than 10% TBSA (adults)

• Moderate burns: 10–20% TBSA

• Severe burns: More than 20% TBSA, or burns involving critical areas (face, hands, feet, perineum)

Example: A second-degree burn covering the entire right arm (approximately 9% TBSA) would be considered mild to moderate, depending on the patient's age and overall health.

Types of Cancerous Skin Tumors

Skin cancer is the abnormal growth of skin cells, often due to ultraviolet (UV) radiation exposure. There are three main types of cancerous skin tumors, each with distinct characteristics and risks.

• Basal cell carcinoma (BCC): The most common and least dangerous type. Originates in the basal cells of the epidermis. Appears as a pearly or waxy bump, often on sun-exposed areas. Rarely metastasizes but can cause local tissue destruction if untreated.

• Squamous cell carcinoma (SCC): Arises from squamous cells in the epidermis. Presents as a firm, red nodule or a flat lesion with a scaly, crusted surface. Has a higher risk of spreading (metastasizing) than BCC, especially if not treated early.

• Malignant melanoma: The most dangerous form of skin cancer. Develops from melanocytes (pigment-producing cells). Appears as a new or changing mole with irregular borders, multiple colors, and asymmetry. High potential for metastasis and requires prompt treatment.

Example: A patient with a rapidly growing, irregularly pigmented lesion on the back should be evaluated for melanoma, which is aggressive and can spread quickly.