Microscopic examination of a tumor shows Call-Exner bodies. They are seen in:
**Core Concept**
Call-Exner bodies are a characteristic histological feature of granulosa cell tumors, which are a type of sex cord-stromal tumor. These structures are formed by the accumulation of small fluid-filled spaces around a central blood vessel, giving them a distinctive appearance under microscopic examination.
**Why the Correct Answer is Right**
Call-Exner bodies are formed as a result of the accumulation of fluid within the tumor stroma, which is thought to be related to the secretion of glycosaminoglycans by the tumor cells. This fluid accumulation creates small, fluid-filled spaces that surround a central blood vessel, giving the appearance of a "rosette" or "flower-like" structure. The presence of Call-Exner bodies is a key diagnostic feature of granulosa cell tumors, which are often seen in the ovary.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Call-Exner bodies are not typically seen in fibrothecomas, which are a type of sex cord-stromal tumor that lacks these characteristic structures.
**Option B:** This option is incorrect because Call-Exner bodies are not typically seen in Brenner tumors, which are a type of ovarian tumor that consists of transitional epithelial cells.
**Option C:** This option is incorrect because Call-Exner bodies are not typically seen in clear cell carcinomas, which are a type of ovarian epithelial tumor that is characterized by the presence of glycogen and mucin.
**Clinical Pearl / High-Yield Fact**
The presence of Call-Exner bodies on microscopic examination is a key diagnostic feature of granulosa cell tumors, which are often seen in young women and can be associated with estrogen production.
**Correct Answer:** D.