Basal cell carcinoma (BCC), sometimes referred to as a "rodent ulcer" due to its potential to cause local tissue destruction if left untreated, is the most common form of skin cancer. Here's a brief overview:

 What is Basal Cell Carcinoma?
- **Definition:** BCC originates in the basal cells, which are found at the bottom of the epidermis (the outermost layer of the skin).
- **Appearance:** It often appears as a small, shiny bump or a flat, scar-like lesion. The color can vary, but it's commonly flesh-colored, pink, or black.
- **Growth:** These cancers grow slowly and usually do not spread (metastasize) to other parts of the body, but they can grow deep into local tissues if not treated.

Symptoms:
- A new growth on the skin, especially in sun-exposed areas like the face, ears, neck, shoulders, or back.
- A sore that doesn't heal, might bleed, or develop a crust.
- A shiny, skin-colored bump that's translucent with visible blood vessels.
- A flat, scaly, reddish patch with a raised border.

 "Rodent Ulcer":
- The term "rodent ulcer" stems from the way the cancer can eat away at the skin and underlying tissue, somewhat reminiscent of a rodent gnawing. This term, however, is more historical and less used in modern medical literature.

Treatment:
- **Surgery:** Excision or Mohs surgery (which is very effective for BCC because it allows for the removal of cancer layer by layer while sparing healthy tissue).
- **Other Methods:** Radiation therapy, topical treatments, or photodynamic therapy for certain cases.

### Prevention:
- **Sun Protection:** Use sunscreen, wear protective clothing, avoid midday sun, and seek shade.
- **Regular Check-ups:** Especially for those with a history of skin cancer or significant sun exposure.

### Diagnosis:
- **Biopsy:** A sample of the skin is taken and examined under a microscope to confirm BCC.