All originate from epidermis.
| Feature | Basal Cell Carcinoma (BCC) | Cutaneous squamous Cell Carcinoma (SCC) | Melanoma |
|---|---|---|---|
| Classic Look | ”Pearly” papule with telangiectasias; often has central ulceration. | Erythematous, scaly patch or nodule; often ulcerated or crusted. | Asymmetric, pigmented lesion with irregular borders & color. ABCDEs. |
| Cell of Origin | Basal cells of the epidermis. | Keratinocytes in the stratum spinosum. | Melanocytes |
| Location | Sun-exposed areas (esp. face, nose). | Sun-exposed areas (face, lower lip, hands). | Sun-exposed areas (back in men, legs in women). |
| Precursor | De novo. | Actinic keratosis, chronic wounds (e.g., burn scar). | Dysplastic nevus or de novo. |
| Pathology | Peripheral palisading of basaloid cells. | Keratin pearls & intercellular bridges. | Atypical melanocytes. |
| Behavior | Locally invasive; rarely metastasizes. | Low metastatic risk, but ↑ in immunosuppressed pts. | High metastatic potential; prognosis based on Breslow depth. |