Localized ENT Amyloidosis – Literature Overview

Abstract

Amyloidoses from a group of disorders characterized by extracellular tissue accumulation of amorphous hyaline material. They are categorized in two main forms: systemic and localized (Zhuang YL, 2005). Localized forms involve a single organ, whereas systemic amyloidosis involves multiple organ systems. Localized forms often involve the head and neck. The aerodigestive tract is a common location, the nasopharynx or soft palate are rarely envaded (Panda NK, 2007) (Pitkaranta A, 2000). The distinction between localized and systemic disease is important because localized amyloidosis can be managed conservatively with an excellent prognosis, whereas systemic amyloidosis is associated with significant morbidity and mortality (Kyle RA, 1975). Although the pathogenesis is not completely understood, soluble protein subunits undergo a conformational change to become insoluble and aggregate in an antiparallel β-pleated sheet conformation (Panda NK, 2007). The diagnosis of amyloidosis is made based on Congo red staining on tissue biopsy which leads to apple-green birefringence on polarized microscopy (Patel A, 2002). Amyloidomas are benign tumorlike lesions consisting of localized deposits of amyloid and are the rarest form in the group of amyloidosis-related lesions (Parmar H, 2010). Amyloidosis should not be considered as a single clinical entity, but rather as a nonhomogeneous group of diseases characterized by the common presence of a fibrillar structure of linear, aggregated fibers with a cross β-pleated sheet conformation, and evidenced by x-ray diffraction. In primary amyloidosis, a monoclonal population of marrow cells produces either fragments of light chains that may be processed to form amyloid. Secondary amyloidosis is characterized by a defect in the metabolism of the precursor protein (Comenzo RL, 2006). Our objective is to study the epidemioloclinical characteristics of ENT amyloidosis and the management of those localizations.