Primary amyloidosis presenting as an isolated mediastinal mass: diagnosis by fine needle biopsy.

Intrathoracic amyloidosis affecting the lungs or mediastinum is rare, and mediastinal lymphadenopathy in the absence of pulmonary involvement is even more rare. The case history is presented of a previously healthy man who developed nodular mediastinal amyloidosis without pulmonary involvement. Diagnosis was made by percutaneous fine needle biopsy.