title: Asymptomatic tracheal MALT lymphoma discovered on spirometric findings presenting with elevated respiratory resistance.
abstract: BACKGROUND
  Central airway obstruction (CAO) may be caused by various etiologies. However, conventional chest X-rays are rarely diagnostic for patients with CAO.
  
  
  METHODS
  We here described a 64-year-old asymptomatic female with tracheal mucosa-associated lymphoid tissue lymphoma discovered on spirometric findings during a complete physical examination. The plateau of forced expiratory flow was consistent with CAO. A decreased peak expiratory flow rate was noted at least 3 years before the diagnosis, and was attributed to an insufficient effort by the patient. Impulse oscillometric measurements, which were taken during quiet breathing and were effort-independent, suggested elevated respiratory resistance. These abnormalities completely disappeared after radiation therapy.
  
  
  CONCLUSIONS
  The addition of impulse oscillometry to spirometry may be useful for screening CAO in routine health examinations.
authors.affiliation: Division of Pulmonary Medicine, National Hospital Organization National Kochi Hospital, 1-2-25 Asakuranishimachi, Kochi, 780-8077, Japan. naoki_kadota.usa@kta.biglobe.ne.jp.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kadota
authors.affiliation: Department of Clinical Investigation, National Hospital Organization National Kochi Hospital, 1-2-25 Asakuranishimachi, Kochi, 780-8077, Japan. shinoharat@kochi2.hosp.go.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Shinohara
authors.affiliation: Division of Pulmonary Medicine, National Hospital Organization National Kochi Hospital, 1-2-25 Asakuranishimachi, Kochi, 780-8077, Japan. machidah@kochi2.hosp.go.jp.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Machida
authors.affiliation: Kochi Kenshin Clinic, 2-4-36 Chiyori-cho, Kochi, 780-0806, Japan. nackdoct@hotmail.com.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nakanishi
authors.affiliation: Kochi Kenshin Clinic, 2-4-36 Chiyori-cho, Kochi, 780-0806, Japan. chanachan@poppy.ocn.ne.jp.
authors.forename: Fumie
authors.initials: F
authors.lastname: Suehiro
authors.affiliation: Department of Pathology, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan. toda@fmed.jp.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Toda
authors.affiliation: Department of Pathology, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan. yoshino@md.okayama-u.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshino
authors.affiliation: Division of Pulmonary Medicine, National Hospital Organization National Kochi Hospital, 1-2-25 Asakuranishimachi, Kochi, 780-8077, Japan. fogushi@kochi.hosp.go.jp.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Ogushi
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D000403:Airway Resistance; D058070:Asymptomatic Diseases; D001706:Biopsy; D001999:Bronchoscopy; D005260:Female; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000532:radiotherapy; D008875:Middle Aged; D011237:Predictive Value of Tests; D013147:Spirometry; D014057:Tomography, X-Ray Computed; D014134:Tracheal Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000532:radiotherapy; D016896:Treatment Outcome