18F-FDG-PET-CT with Little Value in Different Diagnosis between Pulmonary Malignancy and Amyloidosis

Abstract

Pulmonary amyloidosis is rare and is often misdiagnosed due a lack of general awareness of the condition. The role of PET-CT in the differential diagnosis between pulmonary amyloidosis and lung malignant tumors is still unclear. Herein, we describe a 61-year-old Chinese woman who presented with a right lower lobe pulmonary nodule, and right hilar and mediastinal lymph nodes shadows. On PET-CT examination, the patient was found to have right lower lung malignant lesions with multiple right hilar and mediastinal lymph node metastases. She was diagnosed with nephrotic syndrome with a history of pathologic type of amyloidosis over the previous two months. After performing right thoracotomy, a histopathologic diagnosis of pulmonary amyloidosis was made. The patient has done well postoperatively, showing no local recurrence in the lung or deterioration of her condition in a 12-month follow-up period. The pathology of nephrotic syndrome in patients with amyloidosis led to the diagnosis of systemic amyloidosis being made in this patient. From this case, combined with the domestic and international literature, we conclude that PET-CT is of little value for the different diagnosis between pulmonary amyloidosis and lung malignant tumors.