DAY 2 — CASE 13 (Chronic fistula): A patient has a chronic fistula with a photograph and radiograph. What is the clinical diagnosis of the soft tissue lesion?

Correct answer: C. Parulis

• A. Fibroma is a firm, pink, non-bleeding reactive lesion from local irritation — not associated with a draining sinus tract.
• B. Pyogenic granuloma is a vascular reactive lesion often associated with trauma or hormonal changes — appears as a red, bleeding nodule. It is NOT the lesion at a sinus tract opening.
• C. A PARULIS (gum boil) is the clinical soft-tissue finding associated with a chronic draining sinus tract from a periapical or periodontal abscess. It appears as a raised, pink-red papule/nodule on the attached gingiva or alveolar mucosa at the opening of the sinus tract. When a chronic fistula is present with a sinus tract opening on the gingiva, the soft tissue swelling is called a parulis.
• D. Peripheral ossifying fibroma arises from the gingiva, often interdentally — not the diagnosis for a sinus tract opening.