A 59-year-old Chinese female was referred to the chest clinic of the First Affiliated Hospital, College of Medicine, Zhejiang University (Hangzhou, China) in April 2011 due to a two-month history of cough, hemoptysis and general fatigue. A CT scan of the chest revealed a nodule in the left lower lung with mild enhancement in the lesion. The nodule progressed during the two-month follow-up period under treatment with anti-infection drugs. No other significant history was noted. The patient’s physical examination was unremarkable, and hematological and biochemical parameters were within normal limits.\nA dual phase FDG PET/CT scan was performed following six hours of fasting. FDG (5.5 MBq/kg) was injected intravenously through an antecubital vein while the patient remained at rest. Image acquisition was subsequently conducted using a Siemens Biograph 16 PET-CT scanner (Siemens Medical Solutions USA, Inc., Malvern, PA, USA). The PET/CT images revealed a 1.83×1.40 cm slightly lobulated nodule, with burr-like margins in the left lower lung, exhibiting moderately increased F-18 FDG uptake (maximum SUV of 2.6) in the initial images (1 h following the FDG injection), and more intense FDG uptake with an SUV of 3.5 (26.9% increase) in the delayed images (2 h following the injection) (). Based on the dual phase FDG PET/CT imaging findings, morphological features, contrast-enhanced chest CT imaging and medical history (progression of the nodule during the two-month follow-up period), lung malignancy was highly suspected. A percutaneous CT-guided thoracoscopic biopsy was subsequently performed. Histological examination revealed that the specimens contained amorphous, homogeneous material with a number of polyclonal plasma cells, lymphocytes and giant cells. Eosinophilic material exhibited apple-green birefringence under polarizing microscopy. Immunohistochemically, congo red staining was positive, and trichrome staining was negative, confirming the deposition of amyloid within the specimen (). Therefore, a diagnosis of primary nodular parenchymal pulmonary amyloidosis was determined, and the patient was discharged without chemotherapy and other treatment. After May 2011, the patient was followed up every 3 months and was in good clinical condition at the time of writing.
A 67-year-old male ex-smoker (>20 years) with a 30 pack-year history was investigated for morning cough and clear sputum with no constitutional symptoms and an active lifestyle. Past medical history included chronic obstructive pulmonary disease and ischaemic heart disease. External physical examination was unremarkable. Chest computed tomography (CT) showed a right middle lobe nodule which increased from 11 mm to 16 mm over six months. A positron emission tomography (PET) scan showed low radiolabeled [18F]-2-fluoro-2-deoxy-D-glucose (FDG) uptake with a standardised uptake value (SUV) max of 2.0 and no evidence of metastatic disease (). CT-guided biopsy identified eosinophilic amorphic material, which was Congo red negative, with no definitive diagnosis reached. Due to the volume increase of the suspicious lesion, a right middle lobe lobectomy was performed.