‘‘Quasi-Symmetric’’ FDG Avidity of Bilateral Salivary Glands in Mikulicz Disease Yielding False-Positive Staging in Lung Cancer Li-Fan Lin, MD,* Daniel HY Shen, MD, PhD,* Wen-Chiuan Tsai, MD,Þ Cheng-Han Hou, MD,* Cheng-Yi Cheng, MD, PhD,* and Ching-Yuan Chen, MDþ Abstract: A 77-year-old man with lung cancer underwent fluorodeoxyglu- cose (FDG) positron emission tomography/computed tomography (PET/ CT). Cervical FDG uptake of variable intensity was detected corresponding to enlarged masses in the bilateral parotid and left submandibular regions. We suspected metastases from primary lung cancer or coexisting salivary gland neoplasms. Histopathological examination of the FDG-avid parotid mass revealed Mikulicz disease, an uncommon autoimmune disease involv- ing the salivary glands. We present this case of Mikulicz disease with ‘‘quasi- symmetric’’ FDG avidity in the major salivary glands. We believe that salivary FDG uptake can lead to erroneous interpretation of tumor staging using PET. Key Words: Mikulicz disease, FDG PET, salivary gland, lung cancer (Clin Nucl Med 2012;37: 1102Y1104) REFERENCES 1. Even-Sapir E, Lerman H, Gutman M, et al. The presentation of malignant tumours and pre-malignant lesions incidentally found on PET-CT. Eur J Nucl Med Mol Imaging. 2006;33:541Y552. 2. Basu S, Houseni M, Alavi A. Significance of incidental fluorodeoxyglucose up- take in the parotid glands and its impact on patient management. Nucl Med Commun. 2008;29:367Y373. 3. Matsuda M, Sakamoto H, Okamura T, et al. Positron emission tomographic im- aging of pleomorphic adenoma in the parotid gland. Acta Otolaryngol Suppl. 1998;538:214Y220. 4. Okamura T, Kawabe J, Koyama K, et al. Fluorine-18 fluorodeoxyglucose posi- tron emission tomography imaging of parotid mass lesions. Acta Otolaryngol Suppl. 1998;538:209Y213. 5. Rubello D, Nanni C, Castellucci P, et al. Does 18 F-FDG PET/CT play a role in the differential diagnosis of parotid masses. Panminerva Med. 2005;47:187Y189. 6. Wang HC, Zuo CT, Hua FC, et al. Efficacy of conventional whole-body (1)F-FDG PET/CT in the incidental findings of parotid masses. Ann Nucl Med. 2010; 24:571Y577. 7. Mikulicz J. Concerning a peculiar symmetrical disease of the lacrimal and sal- ivary glands. Med Class 2 (Berliner Klin) Vochenschrift. 1937;759:165Y186: (In German). 8. Yamamoto M, Takahashi H, Sugai S, et al. Clinical and pathological character- istics of Mikulicz’s disease (IgG4-related plasmacytic exocrinopathy). Autoim- mun Rev . 2005;4:195Y200. 9. Suga K, Kawakami Y, Hiyama A, et al. F-18 FDG PET-CT findings in Mikulicz disease and systemic involvement of IgG4-related lesions. Clin Nucl Med. 2009;34:164Y167. INTERESTING IMAGE 1102 www.nuclearmed.com Clinical Nuclear Medicine & Volume 37, Number 11, November 2012 Received for publication October 17, 2011; and revision accepted June 30, 2012. From the *PET Center and Department of Nuclear Medicine; †Department of Pathology, Tri-Service General Hospital & National Defense Medical Center, 325, Cheng-Kung Road, Sec. 2, Taipei; and ‡Department of Nuclear Medicine, Buddhist Tzu-Chi Hospital, Taichung Branch, Taiwan, Republic of China. Conflicts of interest and sources of funding: none declared. Reprints: Daniel HY Shen, MD, PhD, PET Center and Department of Nuclear Medicine, Tri-Service General Hospital, 325, Cheng-Kung Road, Sec. 2, Taipei 114, Taiwan, Republic of China. E-mail: shen8484@yahoo.com. Copyright * 2012 by Lippincott Williams & Wilkins ISSN: 0363-9762/12/3711Y1102 Copyright © 2012 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.