title: Coexistence of lung cancer and immunoglobulin G4-related lung disease in a nodule: a case report.
abstract: BACKGROUND
  Immunoglobulin G4-related disease is characterized by infiltration of immunoglobulin G4-positive plasmacytes in various organs. The radiological findings of lung involvement of immunoglobulin G4-related disease include hilar and mediastinal lymphadenopathies, thickness of bronchovascular bundles, peribronchovascular consolidation, and lung nodules. Although a pathological approach is needed to diagnose immunoglobulin G4-related disease, it is ordinarily diagnosed by biopsy from one lesion even if there are multiple lesions. We reported a rare case of the coexistence of immunoglobulin G4-related disease and lung cancer in the same lung nodule.
  
  
  METHODS
  A 72-year-old Japanese man visited our hospital for evaluation of a nodular shadow in the middle lobe of his right lung that was seen on chest radiograph and computed tomography scan. An abdominal computed tomography scan showed a tumefactive lesion in his anterior sacral spine. Blood examinations revealed high serum immunoglobulin G4 concentration at 346 mg/dl, renal dysfunction, and anemia. He underwent right upper lobectomy and regional lymph node dissection. Pathologic findings of the lung nodule showed lepidic pattern adenocarcinoma with infiltration of immunoglobulin G4-positive plasma cells and obliterative phlebitis.
  
  
  CONCLUSIONS
  To date, there have been only few reports on the coexistence of immunoglobulin G4-related disease and lung cancer; here, we report such a rare case. Histologic examination should be considered in cases of suspicious immunoglobulin G4-related disease appearing in a lung nodule.
authors.affiliation: Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tashiro
authors.affiliation: Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan. takahak@cc.saga-u.ac.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Komiya
authors.affiliation: Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Sueoka-Aragane
mesh_terms: D000230:Adenocarcinoma / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications* / Q000000981:diagnostic imaging / Q000276:immunology / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008175:Lung Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology; D000072078:Positron Emission Tomography Computed Tomography; D013902:Radiography, Thoracic; D003074:Solitary Pulmonary Nodule / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D007074:Immunoglobulin G
keywords: IgG4-related disease; Lung cancer; Lung nodule