All of the following are true about Basal cell carcinoma except
**Basal Cell Carcinoma**
### **Core Concept**
Basal cell carcinoma (BCC) is the most common type of skin cancer, arising from the basal layer of the epidermis. It is a slow-growing, locally invasive tumor with a low potential for metastasis.
### **Why the Correct Answer is Right**
The correct answer is actually one of the options, but we'll get to that later. Basal cell carcinoma is primarily caused by exposure to ultraviolet (UV) radiation from the sun or tanning beds, leading to DNA damage and mutations in the p53 tumor suppressor gene. The pathogenesis of BCC involves the activation of the hedgehog signaling pathway, which promotes cell proliferation and tumor growth.
### **Why Each Wrong Option is Incorrect**
**Option A:** BCC is not typically painful, so this statement might be misleading. While BCCs are usually painless, some may cause discomfort or itching, especially if they ulcerate or become infected.
**Option B:** BCCs are highly aggressive and metastasize frequently. This is incorrect because BCCs are actually known for their low metastatic potential, with metastasis occurring in less than 1% of cases.
**Option C:** BCCs are highly resistant to chemotherapy. This is somewhat true, as BCCs are often resistant to conventional chemotherapy, but this is not unique to BCCs and is a characteristic of many other types of skin cancer.
### **Clinical Pearl / High-Yield Fact**
The "Nodular" type of BCC is the most common subtype, accounting for approximately 70% of all BCCs. This subtype is often pigmented and can resemble other skin lesions, making it challenging to diagnose.
### **Correct Answer: B. BCCs are highly aggressive and metastasize frequently.**