A patient with a draining sinus tract (fistula) that has been present for over 1 year is biopsied. What type of cells would be MOST prominent in the tissue?

Correct answer: D. Monocytes/Macrophages

• A. Mast cells are involved in allergic (Type I hypersensitivity) reactions — not the dominant cell in chronic fistulas.
• B. Eosinophils are elevated in allergic reactions and parasitic infections — not chronic odontogenic fistulas.
• C. Neutrophils predominate in ACUTE inflammation — a fistula present for 1 year is chronic.
• D. Correct. Chronic inflammation is characterized by monocytes (which differentiate into macrophages in tissues). Macrophages are the dominant phagocytic cell in chronic inflammatory responses. A fistula present for 1 year is chronic — macrophages/monocytes are the predominant cell type.