**Core Concept**
The lacrimal gland is a compound racemose gland that produces tears to moisten and protect the eye. Epithelial tumors of the lacrimal gland are rare and can be benign or malignant. The most common type of epithelial tumor of the lacrimal gland is a type of benign tumor.

**Why the Correct Answer is Right**
Pleomorphic adenoma, also known as benign mixed tumor, is the most common epithelial tumor of the lacrimal gland. It is a benign neoplasm that arises from the epithelial cells of the gland and can cause enlargement of the gland, leading to symptoms such as tearing, redness, and vision changes. The tumor is characterized by its ability to contain a mixture of epithelial and mesenchymal tissues, such as cartilage, bone, and myxoid matrix. This unique combination of tissues gives the tumor its pleomorphic nature.

**Why Each Wrong Option is Incorrect**
**Option A:** Adenoid cystic carcinoma is a malignant tumor that can arise from the salivary glands, but it is much less common than pleomorphic adenoma in the lacrimal gland.

**Option C:** Squamous cell carcinoma is a type of malignant skin cancer that can occur on the eyelid, but it is not typically associated with the lacrimal gland.

**Option D:** Non-Hodgkin's lymphoma is a type of cancer that affects the immune system and can occur in the orbit, but it is not the most common epithelial tumor of the lacrimal gland.

**Clinical Pearl / High-Yield Fact**
Pleomorphic adenoma of the lacrimal gland is often referred to as a "benign tumor," but it can still cause significant morbidity if left untreated. Early detection and surgical excision are essential to prevent recurrence and preserve vision.

**Correct Answer:**
✓ Correct Answer: B. Pleomorphic adenoma