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Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia and Granulomatous Inflammation Mimicking High-Grade Malignancy on FDG-PET/CT Joyce Hsu, BS,* Leo Jia, BA,* Darko Pucar, MD, PhD,† Hadyn Williams, MD,† and Jayanth Keshavamurthy, MD‡ Abstract: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare form of preinvasive lung lesion associated with indolent carcinoid tumor formation. This disease is characterized by multiple small pulmonary nodules with low SUVmax on 18F-FDG PET. Biopsy and immunohistochemical staining for neuroendocrine markers confirm diagnosis. There is no consensus for treatment, which typically involves surgical excision or management of symptoms with steroid-based therapies. We report an unusual case of DIPNECH colocalizing with necrotizing granulomatous inflammation mimicking high-grade aggressive malignancy on FDG-PET and a typical case of DIPNECH for comparison with low FDG avidity. Key Words: DIPNECH, FDG-PET, necrotizing granulomatous inflammation (Clin Nucl Med 2017;42: 47–49)
Received for publication June 1, 2016; revision accepted September 12, 2016. From the *School of Medicine, and †Nuclear Medicine Section, and ‡General/ Cardiothoracic Radiology Section, Department of Radiology & Imaging, Medical College of Georgia, Augusta University, Augusta, GA. Conflicts of interest and sources of funding: none declared. Correspondence to: Darko Pucar, MD, PhD, Department of Radiology & Imaging, Medical College of Georgia, Augusta University, 1120 15th St, BA-1411, Augusta, GA 30912. E-mail:
[email protected]. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0363-9762/17/4201–0047 DOI: 10.1097/RLU.0000000000001438
REFERENCES 1. Wirtschafter E, Walts AE, Liu ST, et al. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia of the lung (DIPNECH): current best evidence. Lung. 2015;193:659–667. 2. Moore W, Freiberg E, Bishawi M, et al. FDG-PET imaging in patients with pulmonary carcinoid tumor. Clin Nucl Med. 2013;38:501–505. 3. Erasmus JJ, McAdams HP, Patz EF Jr, et al. Evaluation of primary pulmonary carcinoid tumors using FDG PET. AJR Am J Roentgenol. 1998;170: 1369–1373. 4. Kayani I, Conry BG, Groves AM, et al. A comparison of 68Ga-DOTATATE and 18F-FDG PET/CT in pulmonary neuroendocrine tumors. J Nucl Med. 2009;50:1927–1932. 5. Tatci E, Ozmen O, Gokcek A, et al. 18F-FDG PET/CT rarely provides additional information other than primary tumor detection in patients with pulmonary carcinoid tumors. Ann Thorac Med. 2014;9:227–231. 6. Krüger S, Buck AK, Blumstein NM, et al. Use of integrated FDG PET/CT imaging in pulmonary carcinoid tumours. J Intern Med. 2006;260:545–550. 7. Bertino EM, Confer PD, Colonna JE, et al. Pulmonary neuroendocrine/carcinoid tumors. Cancer. 2009;115:4434–4441. 8. Gorshtein A, Gross DJ, Barak D, et al. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and the associated lung neuroendocrine tumors. Cancer. 2012;118:612–619.
Clinical Nuclear Medicine • Volume 42, Number 1, January 2017 Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
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Clinical Nuclear Medicine • Volume 42, Number 1, January 2017
FIGURE 1. Intense uptake in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) colocalized with necrotizing granulomatous inflammation. A 68-year-old never-smoker woman with chronic dry cough had a 1.6 1.6-cm intensely avid nodule (SUVmax = 14) on FDG-PET, suggestive of aggressive malignancy. Anterior FDG-PET MIP (A) shows focal intense uptake (arrow) in the right middle lung lobe (B, transaxial PET/CT; C, coronal PET/CT; D, transaxial CT, lung window). Biopsy with synaptophysin immunohistochemical staining and subsequent pathology report confirmed DIPNECH colocalized with necrotizing granulomatous inflammation, explaining high FDG avidity.
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Clinical Nuclear Medicine • Volume 42, Number 1, January 2017
Granulomatous Inflammation PET/CT
FIGURE 2. Mild uptake in typical DIPNECH without associated granulomatous inflammation. A 74-year-old woman who also presented with a dry cough was found to have multiple spiculated pulmonary nodules throughout both lungs on anterior FDG-PET MIP (A) after incidental findings on CTA indicated further workup (B, transaxial PET/CT; C, coronal PET/CT; D, transaxial CT, lung view). Biopsy of a 1.3-cm nodule in the right upper lobe (SUVmax = 1.4) confirmed diagnosis of DIPNECH. The most active conglomerate of nodules was in the right lower lobe with SUVmax = 2, activity ranging from lung background to blood pool. Similar presentations involving multiple small (
