**Core Concept:** Call-Exner bodies are intracytoplasmic granules found in certain types of tumors, specifically in granulosa cell tumors of the ovaries. They are composed of calcium oxalate and are an important diagnostic feature for these tumors.

**Why the Correct Answer is Right:** Granulosa cell tumors are a type of sex cord-stromal tumor that originates from the cells surrounding the ovarian follicles. Call-Exner bodies are formed due to the accumulation of calcium oxalate crystals within the tumor cells. These bodies are absent or rare in other ovarian tumors, distinguishing granulosa cell tumors from other ovarian lesions which may also contain calcium oxalate, like some dermoid cysts or endometriosis.

**Why Each Wrong Option is Incorrect:**

A. **Option A:** Granulosa cell tumors are not the only ovarian tumors containing calcium oxalate. Dermoid cysts can also have intracytoplasmic calcium oxalate crystals, but the absence of Call-Exner bodies in these cases helps to differentiate between granulosa cell tumors and dermoid cysts.

B. **Option B:** Ovarian endometriosis may contain calcium oxalate crystals, but the presence of Call-Exner bodies in granulosa cell tumors is a crucial distinguishing feature.

C. **Option C:** Some ovarian tumors may contain calcium oxalate crystals, but the presence of these bodies is not a defining feature for any specific tumor type.

D. **Option D:** Although some ovarian tumors may have calcium oxalate crystals, the specific combination of these crystals with the characteristic histopathological features of granulosa cell tumors is what distinguishes them from other ovarian lesions.

**Clinical Pearl:** The presence of Call-Exner bodies in granulosa cell tumors is an essential diagnostic clue that aids in differentiating these tumors from other ovarian lesions, particularly dermoid cysts and endometriosis.

**Correct Answer:** Option D (Some ovarian tumors may have calcium oxalate crystals, but the specific combination of these crystals with the characteristic histopathological features of granulosa cell tumors is what distinguishes them from other ovarian lesions, particularly dermoid cysts and endometriosis.