title: F-18-fluorodeoxyglucose positron emission tomography-guided sampling of mediastinal lymph nodes in the diagnosis of cardiac sarcoidosis.
abstract: Histologic proof of granulomatous inflammation is prerequisite for the diagnosis of cardiac sarcoidosis (CS). Because of the limited sensitivity of endomyocardial biopsy (EMB), confirmation of sarcoidosis often has to be acquired from extracardiac biopsies. We set out to review our experience of F-18-fluorodeoxyglucose positron emission tomography (F-18-FDG PET) in guiding extracardiac tissue biopsies in suspected CS. We included in this work 68 consecutive patients with proved CS who had undergone cardiac F-18-FDG PET with (n = 57) or without whole-body imaging as part of initial diagnostic evaluation. Their hospital charts, imaging studies, and diagnostic biopsies were reviewed in retrospect. Whole-body PET images showed extracardiac foci of abnormally high F-18-FDG uptake in 39 of 57 patients, of whom 38 had involvement of mediastinal lymph nodes (MLN). Parallel F-18-FDG uptake was found in other lymph nodes (n = 10), lungs (n = 9), liver (n = 3), spleen (n = 2), and thyroid gland (n = 1). Adding the mediastinal findings at cardiac PET without whole-body imaging, abnormal F-18-FDG uptake in MLN was found in totally 43 of the 68 patients with CS (63%). Histology of systemic sarcoidosis was known at presentation of cardiac symptoms in 8 patients. Of the 60 patients with missing histology, 24 patients underwent mediastinoscopy for sampling of PET-positive MLN, most often (n = 20) after nondiagnostic EMB; microscopy revealed diagnostic noncaseating granulomatous inflammation in 24 of the 24 cases (sensitivity 100%). In the remaining 36 patients, sarcoidosis histology was confirmed by EMB (n = 30), by biopsy of lungs (n = 2) or peripheral lymph nodes (n = 2), or at autopsy (n = 1) or post-transplantation (n = 1). In conclusion, MLN accumulate F-18-FDG at PET in most patients with CS and provide a highly productive source for diagnostic biopsies either primarily or subsequent to nondiagnostic EMB.
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland. Electronic address: piia.simonen@hus.fi.
authors.forename: Piia
authors.initials: P
authors.lastname: Simonen
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Lehtonen
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Riina
authors.initials: R
authors.lastname: Kandolin
authors.affiliation: Department of Nuclear Medicine, HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Schildt
authors.affiliation: Department of Nuclear Medicine, HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Suvi
authors.initials: S
authors.lastname: Marjasuo
authors.affiliation: Heart Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Miettinen
authors.affiliation: Heart Center, Turku University Hospital, Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Airaksinen
authors.affiliation: Heart Center, Turku University Hospital, Turku, Finland.
authors.forename: Tapani
authors.initials: T
authors.lastname: Vihinen
authors.affiliation: Heart Hospital, Tampere University Hospital, Tampere, Finland.
authors.forename: Suvi
authors.initials: S
authors.lastname: Tuohinen
authors.affiliation: Heart Hospital, Tampere University Hospital, Tampere, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Haataja
authors.affiliation: Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Kupari
mesh_terms: D009202:Cardiomyopathies / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012507:Sarcoidosis / Q000175:diagnosis*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18