Laryngeal presentation of systemic apolipoprotein A-I-derived amyloidosis

To study the clinical and pathological characteristics of two patients with laryngeal apolipoprotein A-I (apoA-I)-derived (AApoAI) amyloidosis with the apolipoprotein A-I variants Leu174Ser and Leu178Pro, respectively. The latter variant has not been associated with amyloid before.

Descriptive report of two patients who presented with laryngeal amyloid presumed to be of localized AL type, but in who further assessments demonstrated systemic amyloidosis.

The larynx was examined by videolaryngostroboscopy. The voice was analyzed with the GRBAS system, phonation times, and phonetography. Laryngeal biopsies were stained with Congo red and analyzed immunohistochemically. Organ function was assessed and tissue involvement by amyloid further determined by rectal biopsy, abdominal fat tissue aspirate, and serum amyloid P component scintigraphy.

The appearance of the laryngeal amyloid was unusual in both patients, occurring as small, irregular floppy proliferations affecting the borders of both vocal folds. Amyloid was stained with antibodies to apoA-I and not with antibodies to immunoglobulin light chains. The 45-year-old woman with the previously described amyloidogenic apoA-I Leu174Ser variant had possible involvement by amyloid in joints, peripheral nerves, and heart. Whereas in the 67-year-old man with apoA-I Leu178Pro there was a clinical suggestion of autonomic and cardiac amyloid and histological corroboration of systemic amyloidosis in abdominal fat.

Laryngeal symptoms may be the presenting feature of hereditary systemic AApoAI amyloidosis, and comprehensive investigations including apoA-I genotyping are warranted in patients who present with apparently localized laryngeal amyloidosis. The distinctive appearance of the amyloidotic vocal folds described here may further signal the possibility of hereditary AApoAI type.