**Core Concept**
Reinke crystals are microscopic, eosinophilic, periodic acid-Schiff (PAS)-positive, and diastase-resistant structures found in the cytoplasm of certain ovarian tumors. These crystals are a key diagnostic feature of a specific ovarian neoplasm.

**Why the Correct Answer is Right**
Hilus cell tumors, also known as Leydig cell tumors, are a rare type of sex cord-stromal tumor that originate from the hilus cells of the ovary. These cells are responsible for the production of androgens, such as testosterone. Reinke crystals are a characteristic histopathological feature of Leydig cell tumors, which are composed of large, polygonal cells with abundant eosinophilic cytoplasm. The presence of Reinke crystals is a distinctive diagnostic feature that helps differentiate Leydig cell tumors from other types of ovarian tumors.

**Why Each Wrong Option is Incorrect**
**Option A:** Arrhenoblastoma, also known as Sertoli-Leydig cell tumor, is a rare type of sex cord-stromal tumor that produces androgens, but it is not typically associated with Reinke crystals. Instead, Arrhenoblastoma is characterized by the presence of tubules and rosettes.
**Option B:** Granulosa cell tumors are a type of sex cord-stromal tumor that produce estrogen, and they are not typically associated with Reinke crystals. Granulosa cell tumors are characterized by the presence of Call-Exner bodies and a trabecular pattern.
**Option C:** Dysgerminoma is a type of germ cell tumor that is not associated with Reinke crystals. Dysgerminomas are composed of large, polygonal cells with clear cytoplasm and are often associated with lymphocytic infiltration.
**Option D is the correct answer, so it is skipped.**

**Clinical Pearl / High-Yield Fact**
Reinke crystals are a distinctive feature of Leydig cell tumors, and their presence can help differentiate these tumors from other types of ovarian neoplasms. It is essential to consider the histopathological features of Leydig cell tumors, including the presence of Reinke crystals, when diagnosing ovarian tumors.

**✓ Correct Answer: D. Hilus cell tumor**