**Psammoma Bodies**

**Core Concept**
Psammoma bodies are small, concentrically laminated calcifications found within various types of neoplasms, particularly papillary thyroid carcinoma, serous ovarian cystadenocarcinoma, and meningiomas. These structures are formed through the accumulation of calcium and phosphate ions within the tumor cells.

**Why the Correct Answer is Right**
Psammoma bodies are characteristic features of papillary thyroid carcinoma, arising from the abnormal differentiation of follicular cells. They are formed due to the presence of apical snouts, which are microvilli-like structures that contain high concentrations of calcium and phosphate ions. The deposition of these ions leads to the formation of calcified structures, known as psammoma bodies.

**Why Each Wrong Option is Incorrect**
**Option A:** Psammoma bodies are not typically associated with this condition. However, it is essential to note that some ovarian cancers, like clear cell carcinoma, may exhibit calcifications but are not characteristically associated with psammoma bodies.

**Option B:** Psammoma bodies are indeed seen in this condition, which makes it an incorrect option. Papillary thyroid carcinoma is a classic example of a neoplasm that exhibits psammoma bodies.

**Option C:** Psammoma bodies can be seen in this condition, which makes it an incorrect option. Serous ovarian cystadenocarcinoma is a type of ovarian cancer that often exhibits psammoma bodies.

**Clinical Pearl / High-Yield Fact**
Psammoma bodies are a key feature in the diagnosis of papillary thyroid carcinoma. However, their absence does not rule out the diagnosis, as they can be seen in a small percentage of cases.

**Correct Answer: D.**