**Question:** A biopsy of an enlarged salivary gland from an individual with Sjogren's syndrome is most likely to histologically reveal an extensive infiltrate of

A. Lymphocytes
B. Neutrophils
C. Eosinophils
D. Plasma cells

**Correct Answer:** .

**Core Concept:** Sjogren's syndrome is a chronic autoimmune disorder characterized by lymphocytic infiltration of exocrine glands, leading to decreased gland function and dryness of the eyes and mouth.

**Why the Correct Answer is Right:** In Sjogren's syndrome, the salivary gland biopsy demonstrates a characteristic lymphocytic infiltrate, mainly composed of T cells and B cells. This infiltrate is responsible for the destruction of acinar cells and the subsequent decrease in salivary gland function. Among the given options, lymphocytes are the most relevant cells for this process, making lymphocytes the correct answer.

**Why Each Wrong Option is Incorrect:**

B. Neutrophils: These are the primary cells involved in acute inflammatory processes, not chronic ones like Sjogren's syndrome.

C. Eosinophils: Eosinophils are primarily involved in allergic and parasitic infections, which are not relevant to Sjogren's syndrome.

D. Plasma cells: Although plasma cells are involved in antibody production, they are not the primary cells causing gland damage in Sjogren's syndrome. Lymphocytes play a more significant role in the destruction of acinar cells.

**Clinical Pearl:**

A biopsy of an enlarged salivary gland from an individual with Sjogren's syndrome is most likely to histologically reveal an extensive infiltrate of lymphocytes, highlighting the importance of lymphocytic infiltration in the pathogenesis of the disease. This knowledge is crucial for establishing an accurate diagnosis and understanding the progression of the disease.