Nasopharyngeal amyloidoma: report of three cases and review of the literature

Abstract

Background: Nasopharyngeal amyloidoma is a rare, locally aggressive tumor that has been reported in the English literature in only 38 cases to date, most of which were in the form of case reports. The present study was aimed to summarize the characteristics of this rare tumor, with the goal of providing new insights for diagnosis and treatment.

Materials and methods: We report three cases of nasopharyngeal amyloidoma diagnosed in our hospital following comprehensive medical examination and review the current literature on all cases of nasopharyngeal amyloidoma from PubMed. The journey of nasopharyngeal amyloidoma, including presentation, diagnostics, surgeries, and follow-up was outlined.

Results: None of the three patients had systemic amyloidosis. CT and nasal endoscopy showed irregular masses obstructing the nasopharyngeal cavity. Congo red staining confirmed the deposition of amyloid, and immunohistochemical analysis showed that the amyloid deposition was the AL light chain type. Through literature review, we found that nasopharyngeal amyloidoma most commonly occurred in individuals over the age of 40, patients usually had a good prognosis after complete tumor resection; however, there were still cases of recurrence, and unresected patients were at risk of progression to systemic amyloidosis. The efficacy of radiotherapy and chemotherapy was currently uncertain.

Conclusion: Early clinical and pathological diagnosis is crucial, and surgical intervention is the primary treatment option for this disease. Although patients usually have a favorable prognosis, long-term monitoring is necessary to detect potential relapses and initiate timely intervention.

Keywords: Amyloidosis; Congo red; Localized amyloid; Nasopharyngeal.

Fig. 1

Serum immunofixation electrophoresis was performed on Cases 2 and 3. In both cases, monoclonal immunoglobulins were not detected

Fig. 2

Routine scan, enhanced CT and nasal endoscopy images of three patients. The CT scan revealed low-density, flaky shadows in the nasopharyngeal cavity, with uneven density and an unclear boundary. The enhanced scan displayed mild enhancement and partial non-enhancement. The nasal endoscopy revealed an irregular, gray-red mass obstructing the nasopharyngeal cavity, accompanied by a rough mucosal surface

Fig. 3

HE and Congo red staining of amyloidoma. Under a light microscope (4 ×), amyloid appears as a uniform pink amorphous substance, the same areas exhibit Congo red staining, resulting in a typical brick-red appearance color. Under a polarized light microscope, Congo red-stained slides exhibit a characteristic birefringent apple green color. Additionally, Case 2 demonstrates local cartilage hyperplasia and calcification, as indicated by the red arrow

Fig. 4

The IHC results of amyloid proteins in 3 cases. IHC staining showing κ and λ light chains immunoglobulin expression in amyloid material and nearby plasma cells (200 ×)