**Question:** Psammoma bodies show which type of calcification:

A. Amorphous
B. Mixed
C. Radular
D. Sharply marginated

**Core Concept:**
Psammoma bodies are benign, round, calcified structures found in certain types of tumors, particularly those originating from the epithelial cells in the ovary. They are composed of calcium carbonate crystals, which can be of different types.

**Why the Correct Answer is Right:**
Psammoma bodies are formed due to the process of calcification, which can occur in three types:

1. **Amorphous calcification (Option A):** This type of calcification involves the deposition of calcium salts without a specific pattern, resulting in an irregularly shaped deposit. In the context of Psammoma bodies, amorphous calcification would be represented by randomly arranged calcium carbonate crystals without a defined structure.
2. **Mixed calcification (Option B):** This type of calcification involves the deposition of calcium salts in a mixture of different patterns, resulting in a combination of different crystal arrangements. In the context of Psammoma bodies, mixed calcification would represent a combination of different types of calcium carbonate crystal arrangements.
3. **Sharply marginated calcification (Option D):** This type of calcification involves the deposition of calcium salts within a well-defined boundary, resulting in a distinct, clearly outlined calcified deposit. In the context of Psammoma bodies, sharply marginated calcification would be represented by a distinct, clearly outlined calcium carbonate crystal arrangement within the body.

**Why Each Wrong Option is Incorrect:**
Option C (Radular calcification) is not a relevant answer. Radula is a term associated with the bivalve mollusk's radula, a ribbon-like structure used for grinding food. Therefore, this option is irrelevant to the context of Psammoma bodies.

**Core Concept:** Psammoma bodies are characteristic features of certain types of tumors, particularly those originating from the ovarian cells (termed as "serous papillary cystadenomas") or other epithelial cells. They are composed of calcium carbonate crystals.

**Clinical Pearl:** Psammoma bodies can provide valuable diagnostic information for pathologists and radiologists when assessing calcified lesions. By understanding the patterns of calcification within Psammoma bodies, they can better differentiate benign (Psammoma bodies) from malignant calcified lesions (calcified tumor cells).