**Core Concept**
Mikulicz's disease is a rare autoimmune disorder characterized by the infiltration of granulocytes into the lacrimal and salivary glands, leading to their enlargement and dysfunction. This condition is often associated with other autoimmune diseases, such as rheumatoid arthritis and thyroiditis.

**Why the Correct Answer is Right**
Mikulicz's disease is caused by the abnormal production of autoantibodies that target the secretory cells of the lacrimal and salivary glands. This leads to the infiltration of granulocytes, including lymphocytes and plasma cells, into the glands, resulting in their enlargement and dysfunction. The condition is often associated with the presence of rheumatoid factor and other autoantibodies.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately describe the primary characteristic of Mikulicz's disease.
**Option B:** This option is incorrect as it is a symptom of Mikulicz's disease, not its primary characteristic.
**Option C:** This option is incorrect as it is a different condition altogether.

**Clinical Pearl / High-Yield Fact**
Mikulicz's disease is often associated with other autoimmune diseases, such as rheumatoid arthritis and thyroiditis, and may present with symptoms such as dry eyes and mouth, and swelling of the lacrimal and salivary glands.

**Correct Answer: B. Enlargement of lacrimal and salivary glands.**