[Localized Amyloidosis Involving the Nasal Cavity]

Amyloidosis is a disease characterized by deposits of abnormal protein known as amyloid in various organs and tissues. It can be classified into systemic or localized forms, the latter of which is less frequent. Deposition of amyloidogenic monoclonal light chains leads to the most common type of this disease called light-chain (AL) amyloidosis. (18)F-FDG positron emission tomography/ computed tomography hybrid imaging (FDG-PET/ CT) demonstrates tracer uptake usually in all patients with localized amyloidosis as opposed to the systemic form.

Herein, we present a case of an otherwise healthy 56-year-old women diagnosed with a nasal polyp on the right side. The biopsy results were consistent with amyloidosis. FDG-PET/ CT imaging revealed a pathological, metabolically active lesion measuring 11 × 9 mm with a maximum standardized uptake value (SUV(max)) of 3.47. No other distant pathological changes were identified. After a radical resection, the patient has been regularly followed-up with clinical and imaging methods (MRI, FDG-PET/ CT), both of which repeatedly showed normal findings with disease-free survival of 27 months. Thus, FDG-PET/ CT imaging plays an important role not only for obtaining the right diagnosis but also in the follow-up of patients after surgical resection. In accordance with the literature, this case report confirms that FDG-PET/ CT imaging holds promise as an auxiliary method for distinguishing between localized and systemic forms of amyloidosis.