**Core Concept**
Masquerade syndrome refers to a condition where a malignant tumor mimics a benign or non-neoplastic condition, making diagnosis challenging. In the context of ocular and orbital tumors, Masquerade syndrome is particularly relevant as it can lead to delayed or misdiagnosis, affecting treatment outcomes. The tumors associated with Masquerade syndrome often have non-specific presentations, making a high index of suspicion essential.

**Why the Correct Answer is Right**
Two common tumors associated with Masquerade syndrome are Lymphoma and Leukemia. Lymphoma, particularly non-Hodgkin lymphoma, can present as a unilateral or bilateral orbital mass, mimicking a benign condition such as thyroid ophthalmopathy or a pseudotumor. Similarly, Leukemia can infiltrate the orbit, causing a mass effect or periorbital edema, which can be mistaken for a benign condition such as a thyroid ophthalmopathy or a vasculitic process. The pathogenesis of Masquerade syndrome involves the infiltration of malignant cells into the orbital tissues, leading to a non-specific presentation that can be challenging to diagnose.

**Why Each Wrong Option is Incorrect**
* **Option A:** Not a commonly associated tumor with Masquerade syndrome.
* **Option B:** Not a tumor, but a condition that can be associated with orbital masses.
* **Option D:** Not a commonly associated tumor with Masquerade syndrome.

**Clinical Pearl / High-Yield Fact**
When evaluating a patient with an orbital mass, it is essential to consider the possibility of Masquerade syndrome, particularly if the patient has a history of systemic malignancy or is immunocompromised. A thorough history, physical examination, and imaging studies are crucial in making an accurate diagnosis.

**Correct Answer:** C.