Basal cell carcinoma commonly spreads by-
**Core Concept**
Basal cell carcinoma (BCC) is a type of skin cancer that originates from the basal cell layer of the epidermis. It is the most common form of skin cancer, but unlike other forms of skin cancer, BCC is generally slow-growing and rarely metastasizes to distant sites.
**Why the Correct Answer is Right**
BCC spreads through local invasion and destruction of surrounding tissues, rather than metastasis through the lymphatic or hematogenous routes. This is due to its unique histopathological characteristics, including the formation of small, irregular nests of tumor cells that invade the surrounding dermis and subcutaneous tissue. The lack of lymphatic vessels in the dermis also limits the spread of BCC, making it a locally destructive tumor.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while BCC can cause local destruction and scarring, it is not typically associated with distant metastasis.
**Option B:** This option is incorrect because BCC does not commonly spread through the bloodstream or lymphatic system, unlike other forms of cancer.
**Option C:** This option is incorrect because while BCC can invade surrounding tissues, it is not typically associated with the formation of distant metastases.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that BCC is generally slow-growing and rarely metastasizes, but it can cause significant local destruction and scarring if left untreated. Early detection and treatment are crucial in preventing disfiguring lesions and promoting a good cosmetic outcome.
**Correct Answer: D. Local invasion and destruction of surrounding tissues.**