Differential Diagnosis for Chronic Sinus Infections

Given the patient's symptoms and CT findings, the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Chronic sinusitis due to anatomic variation (concha bullosa): The presence of a concha bullosa, which is an air-filled cavity within the turbinate bone, can obstruct normal sinus drainage and ventilation, leading to chronic sinus infections. The fact that the ostiomeatal units are patent and there is minimal maxillary and ethmoid sinus disease suggests that the anatomic variation might be the primary cause.

• Other Likely Diagnoses

  • Allergic fungal sinusitis: Although the CT shows minimal sinus disease, allergic fungal sinusitis could still be a consideration, especially if the patient has a history of allergies. The concha bullosa might contribute to the accumulation of fungal elements.
  • Bacterial sinusitis: Chronic bacterial infection could be a contributing factor, especially if the patient has had recurrent infections. The concha bullosa might predispose the patient to bacterial colonization.

• Do Not Miss Diagnoses

  • Sinus cancer or other neoplasms: Although rare, any chronic infection or anatomic abnormality could potentially harbor or be associated with a neoplasm. It's crucial to rule out malignancy, especially in a 71-year-old patient.
  • Invasive fungal sinusitis: This is a potentially life-threatening condition that requires prompt diagnosis and treatment. The presence of a concha bullosa and chronic infections might increase the risk.

• Rare Diagnoses

  • Primary ciliary dyskinesia: A rare genetic disorder that affects the motility of cilia and can lead to chronic sinusitis among other respiratory issues. The patient's age and chronic nature of the infections make this less likely but still a consideration.
  • Wegener's granulomatosis (Granulomatosis with Polyangiitis): A rare autoimmune disorder that can cause chronic sinusitis, among other systemic symptoms. The lack of other systemic symptoms or specific findings on the CT makes this less likely.