Which statement about radiographic differentiation of periapical lesions is true?

• A. Periapical abscess, granuloma, and cysts typically appear the same on radiographs.
• B. Abscesses are radiopaque.
• C. Cysts are radiolucent while granulomas are radiopaque.
• D. Radiographs can clearly distinguish all three lesions.

Answer: (A)

Radiographs can show that a lesion exists and where it sits, but they don’t reliably reveal which periapical lesion it is. The main idea here is that periapical abscess, granuloma, and cyst all tend to produce radiolucent areas around the tooth apex, so they typically look the same on X-rays. This is why radiographs alone cannot differentiate them; a definitive diagnosis requires clinical information, pulp vitality testing, how the lesion behaves over time, and sometimes histopathology or surgical findings.

Abscesses are not radiopaque; they usually appear as radiolucent areas, often with ill-defined borders from infection. Cysts and granulomas are both radiolucent on radiographs, and while a cyst may sometimes show a well-circumscribed, corticated border as it enlarges, this isn’t a foolproof differentiator.