title: False positive accumulation in 18F fluorodeoxyglucose positron emission tomography scan due to sarcoid reaction following induction chemotherapy for lung cancer.
abstract: We present a case of lung cancer that showed false positive accumulation in an 18F fluorodeoxyglucose positron emission tomography (FDG-PET) scan following induction chemotherapy for suspected metastasis and progression of malignancy. A 66-year-old man was diagnosed with squamous cell carcinoma in the lung, classified as clinical stage IIIA (T2N2M0), and underwent induction chemotherapy. An FDG-PET scan prior to chemotherapy demonstrated accumulation only in the tumor, whereas following treatment it revealed a strong accumulation not only in the tumor, but also in the supraclavicular lymph nodes, which indicated lymph node metastasis. The patient underwent a biopsy of the right supraclavicular lymph node and mediastinoscopy, after which all dissected lymph nodes showed sarcoid reactions and no tumor cells were found pathologically. We concluded that when evaluating the effect of induction chemotherapy for malignancy, a sarcoid reaction might lead to the false positive accumulation of FDG.
authors.affiliation: Department of Surgery, El, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Maeda
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Ohta
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Hirabayashi
authors.forename: Hikaru
authors.initials: H
authors.lastname: Matsuda
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008171:Lung Diseases / Q000139:chemically induced / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000188:drug therapy; D008297:Male; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012507:Sarcoidosis / Q000139:chemically induced / Q000175:diagnosis* / Q000000981:diagnostic imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18