**Core Concept**
Popcorn calcification refers to a specific type of dystrophic calcification seen in certain types of breast lesions, particularly phyllodes tumors. This type of calcification is characterized by small, popcorn-like calcified particles within the tumor tissue.

**Why the Correct Answer is Right**
Popcorn calcification is a hallmark feature of phyllodes tumors, which are rare, biphasic tumors consisting of both epithelial and stromal components. The calcification is thought to occur due to the degeneration of the stromal component, leading to the formation of calcium deposits. This type of calcification is often seen on mammography or ultrasound and can help differentiate phyllodes tumors from other types of breast lesions.

**Why Each Wrong Option is Incorrect**
**Option A:** While calcifications can be seen in fibroadenomas, they are typically linear or rim-like, not popcorn-like.
**Option B:** Ductal carcinoma in situ (DCIS) is a type of breast cancer that can cause calcifications, but they are typically punctate or linear, not popcorn-like.
**Option C:** Fibrocystic changes can cause calcifications, but they are typically scattered and not organized in a popcorn-like pattern.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that popcorn calcification is a specific type of calcification that can help identify phyllodes tumors, which are often benign but can be locally aggressive. When interpreting mammograms or ultrasound images, keep in mind that popcorn calcification is a key feature of phyllodes tumors.

**Correct Answer:** C.