**Core Concept**
Satellite nodules are a characteristic feature of certain skin lesions, specifically basal cell carcinoma and melanoma. These nodules are smaller growths that occur around the primary tumor, often in a radial or linear pattern.

**Why the Correct Answer is Right**
The formation of satellite nodules is thought to be due to the extension of tumor cells along lymphatic vessels or through direct invasion of adjacent skin. In basal cell carcinoma, satellite nodules are often small, well-circumscribed lesions that may be pigmented or non-pigmented, whereas in melanoma, they can be larger and more irregular. The presence of satellite nodules can aid in the diagnosis and staging of these skin cancers.

**Why Each Wrong Option is Incorrect**
**Option A:** Satellite nodules are not typically seen in dermatofibromas, which are benign skin growths that usually present as single, solitary lesions.
**Option B:** While actinic keratoses can be multiple, they do not typically form satellite nodules around a primary lesion.
**Option C:** Pyogenic granulomas are vascular lesions that can be multiple, but they do not have the characteristic satellite nodule formation seen in basal cell carcinoma and melanoma.

**Clinical Pearl / High-Yield Fact**
When evaluating skin lesions, it's essential to look for features such as satellite nodules, which can be a key distinguishing characteristic between benign and malignant lesions.

**Correct Answer: C. Melanoma**