Amyloidosis is a disease caused by amyloid deposition in tissues or organs. According to the extent of the lesion, it can be divided into systemic amyloidosis and localized amyloidosis. Amyloidosis originating in the larynx accounts for approximately 0.5% to 1.0% of benign lesions of the larynx; such lesions are relatively rare and mostly localized. Nasopharyngeal amyloidosis combined with laryngeal amyloidosis is even rarer. We herein present a case involving a patient with amyloidosis in the nasopharynx and larynx who presented with a foreign body sensation and hoarseness in the pharynx. Electronic fiber laryngoscopy revealed a smooth neoplasm in the left nasopharynx and left vocal cord. The patient underwent surgical treatment, and the postoperative pathologic examination results suggested amyloidosis. Special staining performed using Congo red and crystal violet was positive, confirming amyloidosis. The patient recovered after surgery, and no recurrence was present at the 3- and 6-month follow-ups.

BACKGROUND: AL Amyloidosis is known to be a systemic disease affecting multiple organs and tissue while it\'s rare that patients present with gastrointestinal symptoms at first and later develop multiple-organ dysfuction. Clinical signs are not specific and the diagnosis is rarely given before performing immunofixation and endoscopy with multiple biopsies. We would like to emphasize the value of precise diagnostic process of AL amyloidosis.
METHODS: In this case report, we describe a 56-year-old man who presented with recurrent periumbilical pain for 4 months and gradually worsened over a month. After a series of tests, he was finally diagnosed with primary systemic AL amyloidosis. He was treated with a chemotherapy regimen (Melphalan, dexamethasone and thalidomide) achieving a good clinical response.
CONCLUSIONS: On account of the high misdiagnosis rate, establishing the most precise diagnosis in first time with typing amyloidogenic protein becomes increasingly vital. Although the presenting feature is usually nonspecific, AL amyloidosis ought to be considered when multiple organs are involved in a short period.