In chronic sinusitis imaging, which condition must be ruled out because it can underlie persistent symptoms?

• A. Allergic rhinitis
• B. Foreign body or cancer
• C. Viral URI
• D. Bacterial infection

Answer: (B)

When symptoms of chronic sinusitis persist despite standard treatment, imaging is used to look for an underlying obstructive lesion rather than simple mucosal inflammation. The most important conditions to rule out are a foreign body and a mass or cancer in the nasal/sinus passages, because both can continuously block drainage pathways and keep symptoms going. A foreign body may cause unilateral obstruction and recurrent infections that don’t fully resolve with typical therapy, while a tumor can present with unilateral obstruction, nosebleeds, or facial swelling and requires biopsy and oncologic management. In contrast, allergic rhinitis, viral URI, and bacterial infection can cause sinus symptoms but are less likely to explain persistent, imaging-detectable obstruction without a mass or foreign body. So identifying a foreign body or cancer is essential to explain why symptoms persist and to guide appropriate treatment.