18F-FDG PET/CT in patients with amyloid light-chain amyloidosis: case-series and literature review

Objectives: To describe FDG-PET/CT in amyloid light-chain (AL) amyloidosis. Methods: We describe a French multicenter study which included patients with AL amyloidosis who had undergone a FDG-PET/CT during follow-up. Results: Ten patients with AL amyloidosis (median age 62 years [59–85]) were analyzed. AL amyloidosis was of λ-type in 7/10 cases (70%) and localized amyloidosis in 4/10 cases (40%). AL amyloidosis was primary in 7/10 (70%) cases and associated with Waldenstrom's macroglobulinemia (n = 2) and plasmocytoma (n = 1) in the remaining cases. Median delay between diagnosis and PET was 1 month [0–51]. PET was positive in seven (70%) patients and showed a median FDG SUV of 6.5 [4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 Kung J, Zhuang H, Yu JQ, Duarte PS, Alavi A. Intense fluorodeoxyglucose activity in pulmonary amyloid lesions on positron emission tomography. Clin Nucl Med 2003;28:975–976. Ollenberger GP, Knight S, Tauro AJ. False-positive FDG positron emission tomography in pulmonary amyloidosis. Clin Nucl Med 2004;29:657–658. Currie GP, Rossiter C, Dempsey OJ, Legge JS. Pulmonary amyloid and PET scanning. Respir Med 2005;99:1463–1464. Grubstein A, Shitrit D, Sapir EE, Cohen M, Kramer MR. Pulmonary amyloidosis: detection with PET-CT. Clin Nucl Med 2005;30:420–421. Yadav S, Sharma S, Gilfillan I. Unusual positron emission tomography findings in pulmonary amyloidosis: a case report. J Cardiothorac Surg 2006;1:32. Yoshida A, Borkar S, Singh B, Ghossein RA, Schöder H. Incidental detection of concurrent extramedullary plasmacytoma and amyloidoma of the nasopharynx on [18F]fluorodeoxyglucose positron emission tomography/computed tomography. J Clin Oncol 2008; 26:5817–5819. Seo JH, Lee SW, Ahn BC, Lee J. Pulmonary amyloidosis mimicking multiple metastatic lesions on F-18 FDG PET/CT. Lung Cancer 2010;67:376–379. Costantino F, Loeuille D, Dintinger H, Péré P, Chary-Valckenaere I. Fixed digital contractures revealing light-chain amyloidosis. Joint Bone Spine 2009;76:553–555. Tan H, Guan Y, Zhao J, Lin X. Findings of pulmonary amyloidosis on dual phase FDG PET/CT imaging. Clin Nucl Med 2010;35:206–207. Mainenti PP, Segreto S, Mancini M, Rispo A, Cozzolino I, Masone S, Rinaldi CR, et al. Intestinal amyloidosis: two cases with different patterns of clinical and imaging presentation. World J Gastroenterol 2010;16:2566–2570. Mekinian A, Ghrenassia E, Pop G, Roberts S, Prendki V, Stirnemann J, Weinmann P, Fain O. Visualization of amyloid arthropathy in light-chain systemic amyloidosis on F-18 FDG PET/CT scan. Clin Nucl Med 2011;36:52–53. Soussan M, Ouvrier MJ, Pop G, Galas JL, Neuman A, Weinmann P. Tracheobronchial FDG uptake in primary amyloidosis detected by PET/CT. Clin Nucl Med 2011;36:723–724. ]. FDG uptakes with positive PET were localized in seven patients, namely in the nasopharynx (n = 3), bronchopulmonary (n = 2), duodenal, cutaneous, bone, joint and muscular areas (n = 1, each). FDG uptakes on PET were concordant with the known organ impairment in 6/7 cases (86%) and showed unknown nasopharyngeal and mesenteric localization in one case each. PET was negative in the patient with cardiac amyloidosis and two patients with pulmonary amyloidosis. Conclusion: High FDG uptake may be present in patients with AL amyloidosis, however prospective studies are needed in order to determine the place of FDG PET in AL amyloidosis.