Commonest cancer in burn scar is –
**Core Concept**
The formation of cancer in burn scars is a well-documented phenomenon known as Marjolin's ulcer, which occurs due to the malignant transformation of chronic epithelial hyperplasia in previously damaged skin. This process is thought to be influenced by repeated cycles of inflammation, wound healing, and tissue repair.
**Why the Correct Answer is Right**
The development of Marjolin's ulcer is often associated with squamous cell carcinoma (SCC), which is the most common type of cancer to arise in burn scars. This is likely due to the prolonged exposure of the damaged skin to UV radiation and chronic inflammation, leading to genetic mutations and uncontrolled cell growth. SCC is a type of epithelial cancer that originates from the squamous cells of the skin, which are particularly susceptible to malignant transformation in the setting of chronic injury.
**Why Each Wrong Option is Incorrect**
**Option A:** Basal cell carcinoma (BCC) is also a type of skin cancer, but it is less common in burn scars compared to SCC. While BCC can occur in areas of sun-damaged skin, it is not typically associated with the development of Marjolin's ulcer.
**Option B:** Melanoma is a type of skin cancer that arises from melanocytes, but it is relatively rare in burn scars. The risk factors for melanoma are distinct from those of SCC, and it is not typically associated with the development of Marjolin's ulcer.
**Option C:** Merkel cell carcinoma is a rare type of skin cancer that is often associated with sun exposure, but it is not typically seen in burn scars. While it can occur in areas of sun-damaged skin, it is not the most common type of cancer to arise in burn scars.
**Clinical Pearl / High-Yield Fact**
It's essential for clinicians to be aware of the risk of Marjolin's ulcer in patients with burn scars, particularly if the scar has been present for an extended period. A high index of suspicion and regular follow-up are crucial in the early detection and management of this potentially life-threatening condition.
**Correct Answer:** C. Squamous cell carcinoma.