Heterogeneous 68Ga–Prostate-Specific Membrane Antigen Uptake in the Left Upper Abdomen: Mesenchymal Tumor A 50-year-old man with recently diagnosed prostate adenocarcinoma was referred for whole-body 68Ga–prostate-specific membrane antigen (PSMA) PET/CT scan for staging. Apart from some nonspecific findings, 68Ga-PSMA PET/CT revealed large soft tissue mass in the left upper abdomen showing heterogeneous tracer uptake. Histological examination of the mass was interpreted as gastrointestinal/extragastrointestinal stromal tumor by pathologists. Prostate-specific membrane antigen is considered specific for prostate cancer cells, although PSMA activity has been described in many other benign or malign conditions. That is why PSMA uptake in uncommon locations for prostate cancer metastasis must be considered for second malignancies or other benign conditions. Received for publication May 23, 2019; revision accepted July 23, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Funda Aydin, MD, Department of Nuclear Medicine, Akdeniz University Hospital, H Bloc, Ground Floor, Pinarbaşi District, Konyaalti, Antalya 07058, Turkey. E-mail: afunda@akdeniz.edu.tr. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Renal Metastasis From Neuroblastoma Shown on MIBG Imaging A 6-year-old girl with high-risk neuroblastoma underwent a 123I-MIBG scan to monitor the disease status. In addition to the known lesion in the right retroperitoneal region, there were additional foci of increased activity in the right upper quadrate of the abdomen, which were not typical bowel activity. SPECT/CT images located the activity in the cortex of the lower pole of the right kidney, which was partially calcified. Subsequent biopsy confirmed neuroblastoma metastasis to the right kidney, which is extremely rare. Received for publication August 15, 2019; revision accepted August 19, 2019. Conflicts of interest and sources of funding: This work was partially supported by a fund from Beijing Municipal Administration of Hospitals Incubating Program(grant PX2016023). None declared to both authors. Correspondence to: Zhe Wen, MD, PhD, Department of Nuclear Medicine, Beijing Shijitan Hospital, Capital Medical University, No. 10 Tieyi Road, Haidian District, Beijing 100038, People's Republic of China. E-mail: wenzhedr@foxmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Ectopic Corticotropin-Releasing Hormone–Secreting Pancreatic Neuroendocrine Tumor: Excellent Response of Liver Metastases to Peptide Receptor Radionuclide Therapy as Demonstrated by: 68: Ga-DOTATOC and: 18: F-FDG PET/CT Imaging Ectopic Cushing syndrome secondary to corticotropin releasing hormone (CRH)–secreting tumors or CRH and adrenocorticotropin hormone cosecreting tumors is extremely rare. We report here the case of a 54-year-old man who experienced CRH-secreting pancreatic neuroendocrine tumor causing Cushing syndrome, initially detected by SSTR (somatostatin receptor) scintigraphy, then significantly progressed with multiple liver metastases, demonstrating significantly increased SSTR expression on 68Ga-DOTATOC PET/CT and a “mismatch” imaging pattern on 18F-FDG PET/CT. The patient underwent peptide receptor radionuclide therapy with 177Lu/90Y-DOTATOC and demonstrated excellent response to the treatment. Received for publication July 19, 2019; revision accepted August 17, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Jingjing Zhang, MD, PhD, Theranostics Center for Molecular Radiotherapy and Precision Oncology, Zentralklinik Bad Berka, Robert-Koch-Allee 9, 99437 Bad Berka, Germany. E-mail: jingjing.zhang@zentralklinik.de. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Isolated Nasal Metastasis From Renal Cell Carcinoma 9 Years After Nephrectomy Seen on FDG PET A 56-year-old man presented with intermittent epistaxis. Nasopharyngoscope revealed a hemorrhagic mass occupying the left nasal cavity. The patient had a history of renal clear cell carcinoma. 18F-FDG PET/CT was performed to evaluate the potential lesions systematically. PET/CT images showed low to moderate activity in the region of nasal cavity and paranasal sinuses. No abnormal uptake of 18F-FDG was observed in the rest of the body. Eventually, the mass was pathologically proved to be metastatic renal clear cell carcinoma. Received for publication May 30, 2019; revision accepted August 21, 2019. Y.Y. and Z.Z. contributed equally to this work and shared joint first authorship. Conflicts of interest and sources of funding: none declared. Correspondence to: Zhuzhong Cheng, MD, PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, No. 55, Section 4, South People's Rd, Chengdu 610041, People's Republic of China. E-mail: chengzhuzhong@163.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Assessment of Response to Neoadjuvant Chemoradiotherapy by 18F-FDG PET/CT in Patients With Locally Advanced Esophagogastric Junction Adenocarcinoma Purpose The outcome of locally advanced adenocarcinoma of the esophagogastric junction (AEG) treated with preoperative chemoradiotherapy is heterogeneous, and favorable response to this treatment is a key factor in the patient's prognosis. The aim of this study was to evaluate 18F-FDG PET/CT in assessing metabolic response in patients with AEG. Materials and Methods This prospective study evaluated all consecutive patients with potentially operable locally advanced AEG who were candidates for neoadjuvant chemoradiotherapy. PET/CT and contrast-enhanced thoracoabdominal CT were performed at baseline and 2 weeks after completion of chemoradiotherapy for response evaluation. The response rate was assessed using Response Evaluation Criteria in Solid Tumors criteria for contrast-enhanced thoracoabdominal CT and Positron Emission Tomography Response Criteria in Solid Tumors criteria for PET/CT. The regression rate was assessed using a 5-grade histopathology scoring system of the surgically resected tumor. Metastatic lesions were confirmed by histopathology examination or imaging and clinical follow-up at 6 months. Results A total of 40 cases were finally included in the study. Distant metastases were found in the baseline PET/CT in 6 of 40 cases (retroperitoneal [2] or mediastinal/hiliar [1] lymph nodes and liver [2] or bone [1] metastases) and were therefore excluded from surgery. Pathologic response correlated with the ΛSUVmax threshold of ≤45% (P = 0.033). CT response correlated well with both the baseline SUVmax (P = 0.039) and the ΛSUVmax (P = 0.001). Five-year survival curves for AEG correlated with the ΛSUVmax using a threshold of ≤45% for both progression-free and overall survival. Conclusions 18F-FDG PET/CT is useful for diagnosing nonsuspected metastasis before neoadjuvancy in potentially operable AEG. The ΛSUV correlates with pathologic response and is a long-term independent prognostic factor of survival. Received for publication July 26, 2019; revision accepted August 28, 2019. Conflicts of interest and sources of funding: This work was supported by AGAUR 2017 SGR 1150. None declared to all authors. Correspondence to: David Fuster, PhD, Department of Nuclear Medicine, Hospital Clínic, Villarroel 170, 08036 Barcelona, Spain. E-mail: dfuster@clinic.cat. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Severe Contralateral Striatal Hypometabolism in a Case of Diabetic Nonketotic Hyperglycemic Hemichorea on 18F-FDG PET/CT Brain Chorea induced by diabetic nonketotic hyperglycemia is a rare and poorly understood entity with a favorable prognosis after correction of the hyperglycemia. We present a case of elderly diabetic woman with poorly controlled blood glucose levels, presenting with choreiform movements limited to the right side. 18F-FDG PET/CT showed marked hypometabolism in the basal ganglia contralateral to the side with hemichorea. The metabolic dysfunctions lead to nonketotic hyperglycemic chorea, although poorly understood; the index case demonstrated severe glucose hypometabolism in the striatum and adds to the other reported differential diagnoses for striatal hypometabolism. Received for publication June 3, 2019; revision accepted September 1, 2019. Conflicts of interest and sources of funding: none declared. S.K.V. and S.M. contributed equally as first authors. Correspondence to: Bhagwant Rai Mittal, MD, DNB, Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, A Block, Nehru Hospital, Sector 12, Chandigarh 160012, India. E-mail: brmittal@yahoo.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Isolated Immunoglobulin G4–Related Disease of Nasal Septum and Maxilla: Diagnosis and Follow-up With: 18: F-FDG PET/CT Immunoglobulin G4–related disease (IgG4-RD) is a systemic inflammatory condition that can manifest in atypical locations. We present the case of a middle-aged woman presenting with isolated IgG4-RD of left maxilla and nasal septum, confirmed with 18F-FDG PET/CT. She achieved complete metabolic response with multiple pharmacologic treatment, but 1 year later, she experienced local relapse, and FDG PET/CT found new additional lesions in humeral vasculature and lungs. This case illustrates the usefulness of FDG PET/CT for initial evaluation and monitoring of IgG4-RD with unusual nasomaxillary involvement. Received for publication June 15, 2019; revision accepted September 1, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Omar Dario Rodriguez Fonseca, MD, Servicio de Medicina Nuclear, Hospital Universitario Central de Asturias, Avenida de Roma, s/n, 33011 Oviedo, Spain. E-mail: omarrodriguezfonseca@yahoo.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Multifocal Urinary Bladder Paragangliomas With Negative 68Ga-DOTATATE Uptake and Positive 123I-MIBG Uptake We report a case of an adult male patient with multifocal urinary bladder paragangliomas, which were negative on 68Ga-DOTATATE PET/CT scan, but positive on 123I-MIBG SPECT/CT scan. While the 68Ga-DOTA analog PET/CT exhibits superior performance in diagnosis and staging of pheochromocytoma and paraganglioma, our case demonstrates negative somatostatin receptor expression in this rare entity and indicates that 123I-MIBG SPECT/CT still plays a vital role in characterization of bladder paraganglioma. Received for publication July 6, 2019; revision accepted September 6, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Ming Yang, MD, 13400 E Shea Blvd, Scottsdale, AZ 85259. E-mail: yang.ming@mayo.edu. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

The Monocle Sign in FDG-PET: A Sign of Contralateral Facial Nerve Palsy We report three cases of unilateral 18F-FDG uptake in the orbicularis oculi muscle in subjects with contralateral peripheral facial nerve palsy. We argue that this asymmetric uptake pattern in fact reflects lack of metabolism on the side affected by facial nerve palsy, owing to denervation. Since the unilateral periorbital uptake resembles a monocle, we chose to call this finding the monocle sign. The monocle sign should not be confused with inflammation or tumor, but should prompt a neurological assessment for facial nerve palsy and a potential underlying disease. Received for publication May 21, 2019; revision accepted July 21, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Erika Orita, MD, PhD, Department of Nuclear Medicine, University Hospital Zurich/University of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland. E-mail: Erika.Orita@usz.ch. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Early Detection of Metastatic Prostate Cancer Relapse on 68Ga-PSMA-11 PET/CT in a Patient Still Exhibiting Biochemical Response Prostate cancer (PCa) treatment monitoring usually relies on prostate-specific antigen to detect disease progression or relapse. PET/CT with prostate-specific membrane antigen (PSMA) ligands has shown high accuracy in detecting metastatic PCa lesions and could help assess response to therapy. We describe herein the early relapse detection of a hormone-sensitive metastatic upfront PCa treated with docetaxel on 68Ga-PSMA-11 PET/CT before biochemical progression. PSMA PET/CT should be considered to monitor PCa response to chemotherapy to detect early relapse, regardless of prostate-specific antigen levels, increasing the chances of finding low-volume oligoprogressive disease. Received for publication July 16, 2019; revision accepted July 26, 2019. Contributions: Dr Plouznikoff followed up on the PET/CT scans, reviewed the patient's medical records, and drafted the manuscript. Dr Artigas acted as an expert consultant for the case and revised the manuscript. Dr Sideris and Dr Gil participated in the clinical follow-up of the patient. Dr Flamen revised the manuscript for important intellectual content. Conflicts of interest and sources of funding: N.P. is a recipient of a Detweiler Travelling Fellowship provided by the Royal College of Physicians and Surgeons of Canada. None declared for all other authors. Correspondence to: Nicolas Plouznikoff, MD, PhD, FRCPC, Service de Médecine Nucléaire, Centre Hospitalier de l'Université de Montréal, 1051 Rue Sanguinet, Montréal, Quebec, H2X 0C1, Canada. E-mail: nicolas.plouznikoff@umontreal.ca. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.