Slow Progressing Localized Tumor Like Pharyngeal Mass: What Is Your Diagnosis?

Introduction: Amyloidosis is an idiopathic disorder characterized by the extracellular deposition of normally soluble proteins in an abnormal fibrillar form. Pharyngeal involvement is rare.

Case summary: 24 years old man consulted for chronic bilateral nasal obstruction, associated with upper dysphagia to solids. Nasal endoscopy found multiples masses involving the the pharynx. A cervical computed tomography (CT) scan of the neck had shown tissular heterogeneous process infiltrating the walls of the nasopharynx, oropharynx: soft palate, and the anterior wall of the hypopharynx. A direct laryngoscopy under general anesthesia was realized. The anatomopathological examination of the hypopharyngeal biopsy sample found amorphous acellular interstitial deposits, marked by Congo red, showing yellow-green apple birefringence under polarized light. Immunohistochemistry diagnosed type AL amyloidosis. The amyloidosis assessment to rule out systemic involvement showed no abnormalities. The patient did well over the next several months, but recurrence of the pharyngeal amyloid tumor necessitated additional conservative endoscopic excisions in the 7 months follow up.

Discussion: Amyloidosis in the head and neck is a rare and benign condition that usually takes the form of localized amyloidosis, Pharyngeal involvement is rare. Clinical symptomatology and imaging are poorly specific for pharyngeal involvement, macroscopically, the diagnosis is anatomopathological. Given the rarity of this disease, it is essential to rule out systemic involvement. Amyloid tumors in the pharynx are difficult to treat and commonly recur despite surgical excision.