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 64-year-old man presented with an incidental right lung mass on chest X-ray. Mediastinoscopy and lymph node biopsy confirmed amyloid, remaining asymptomatic until four years later, developing exertional dyspnoea matched by significant increase of the mass by chest radiography. Basic laboratory evaluation and immunohistochemistry was unremarkable. Immunoelectrophoresis revealed a faint immunoglobulin G (IgG) kappa band. No mass spectrometry was performed. Colonic biopsy, bone marrow aspirate, immunophenotyping and trephine were normal. 123I Serum amyloid P-component (SAP) scintigraphy showed abnormal uptake within the mass only. Computerised tomography (CT) revealed mediastinal and hilar lymphadenopathy, with a 9.5 × 6.5 × 10 cm right mediastinal mass containing fat and calcification with a radiological differential diagnosis of a teratoma. F-18 fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/CT demonstrated intermediate to high-grade uptake within the soft tissue and low-grade uptake in the fatty component (). Cardiac magnetic resonance imaging excluded cardiac involvement. Repeat core biopsy demonstrated fibrovascular tissue with focal amyloid deposition. The patient proceeded to surgical mass de-bulking for diagnosis and symptom relief and histology confirmed evidence of amyloid. The patient’s postoperative course was uneventful; no evidence of recurrence three months following surgery and marked symptomic improvement, with disappearance of the IGgk paraprotein following resection, currently planned for local consolidation radiotherapy.