Localized Sinonasal Amyloidosis

Abstract

Localized amyloidosis involving the nasal mucosa is rare, with only 38 published cases reported to date. We report a case of amyloidosis localized to the sinonasal tract. A 61-year-old man presented with a 1-year history of left-sided nasal obstruction. Endoscopic examination and computed tomography revealed the presence of a nasal mass originating from the left inferior turbinate. The patient subsequently underwent an examination under anesthesia and an excision biopsy of the nasal mass. Histology confirmed amyloidosis with no immunospecific stains. Systemic amyloidosis testing was negative, leading to a diagnosis of localized sinonasal amyloidosis of nonamyloid A (AA) subtype. To our knowledge, this is the second reported case of non-AA subtype of the sinonasal tract. The patient was managed conservatively and is currently under close follow-up.

Keywords: amyloidosis; localized; nasal; nasopharyngeal; sinonasal.

Figure 1.

A, Axial CT image showing the mass originated from the posterior aspects of the left inferior turbinate, extending into the postnasal space. B, Coronal CT image: the opacification in the left maxillary sinus was a simple retention cyst not an extension of the tumor. There are also subtle reactive bone changes within the left inferior turbinate and lateral wall as compared to the contralateral side. C, Axial magnetic resonance imaging (MRI) T2-weighted image shows soft tissue density mass in the left maxillary sinus, which is hyperintense postcontrast enhancement and is seen closely abutting the left inferior turbinate extending posteriorly into the nasopharynx. D, Coronal MRI T1-weighted image shows soft tissue density mass in the left maxillary sinus, which is isointense to the adjacent skeletal muscle.

Figure 2.

A, Amyloid on Congo red (×100) showing red stain of the amorphous eosinophilic material. B, Apple-green birefringence under high-intensity cross-polarized light (×100).