Unsuspected systemic amyloidosis diagnosed by fine-needle aspiration of the salivary gland: case report.

Amyloidosis of the head and neck region may represent a local amyloidoma or a manifestation of systemic disease. Involvement of major salivary glands by either primary or secondary forms of amyloidosis is very rare. We describe a case of systemic amyloidosis that initially presented as submandibular gland mass and was diagnosed by fine-needle aspiration (FNA). A 69-year-old male presented with submandibular mass. His past medical history was significant for left forearm melanoma that was excised 6 years ago and tricuspid valve endocarditis after valvular replacement 3 months prior to FNA of the submandibular gland. The patient had no symptoms or clinical and laboratory data suggestive of amyloidosis. FNA specimen showed salivary gland tissue and abundant amorphous material, which stained positive for amyloid with Congo red stain and showed typical birefringence when examined by polarized microscopy. Further workup of the patient revealed generalized amyloidosis with multiorgan involvement by the disease. This case demonstrates that FNA can be a useful technique in the diagnosis of unsuspected amyloidosis.