title: Unusual False-Positive Mesenteric Lymph Nodes Detected by PET/CT in a Metastatic Survey of Lung Cancer.
abstract: Positron emission tomography/computed tomography (PET/CT) is a credible diagnostic modality for detecting primary and metastatic malignancy. PET/CT sometimes shows false positives and negatives, which make clinical diagnosis difficult. A 42-year-old man who had undergone right upper lobectomy for lung cancer 1 year previously had PET/CT for a metastatic survey of the lung. The lung cancer was stage IB (pT2N0M0) bronchioloalveolar carcinoma. PET/CT showed massive (18)F-fluorodeoxyglucose (FDG) uptake in the mesenteric lymph nodes. Because the mesentery is an unusual site of metastasis, the patient was under watchful observation. Another PET/CT after 6 months still showed FDG uptake in the same location, with a slightly increased standard uptake value. A systemic survey was performed, but it did not reveal any malignancies or inflammatory diseases. Eventually, the patient underwent probing laparoscopic surgery. For complete resection of the lymph nodes, laparoscopic ileocecal resection was performed. Histologically, the resected lymph nodes showed reactive lymphadenitis. Glucose transporter 1 immunostainings of the lung cancer and the lymph node were positive and partially positive, respectively. Although PET/CT is a powerful diagnostic modality, clinical interpretation of unusual results is difficult.
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kamiyama
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sakamoto
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Niwa
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Ishiyama
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kojima
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Michitoshi
authors.initials: M
authors.lastname: Goto
authors.affiliation: Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tomiki
authors.affiliation: Department of Human Anatomical Pathology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Nakamichi
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Shiaki
authors.initials: S
authors.lastname: Oh
authors.affiliation: Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Suzuki
keywords: False positivity; Lymph node; Non-small cell lung cancer; Positron emission tomography