TY - JOUR T1 - Nationwide retrospective observational study of idiopathic dendriform pulmonary ossification: clinical features with a progressive phenotype JF - BMJ Open Respiratory Research JO - BMJ Open Resp Res DO - 10.1136/bmjresp-2022-001337 VL - 9 IS - 1 SP - e001337 AU - Yasuhiko Nishioka AU - Yuko Toyoda AU - Ryoko Egashira AU - Takeshi Johkoh AU - Yasuhiro Terasaki AU - Akira Hebisawa AU - Kinya Abe AU - Tomohisa Baba AU - Yuji Fujikura AU - Etsuo Fujita AU - Naoki Hamada AU - Tomohiro Handa AU - Yoshinori Hasegawa AU - Koko Hidaka AU - Takeshi Hisada AU - Shu Hisata AU - Chisato Honjo AU - Kazuya Ichikado AU - Yoshikazu Inoue AU - Shinyu Izumi AU - Motoyasu Kato AU - Takumi Kishimoto AU - Masaki Okamoto AU - Keisuke Miki AU - Masamichi Mineshita AU - Yutaro Nakamura AU - Susumu Sakamoto AU - Masaaki Sano AU - Yoshikazu Tsukada AU - Mari Yamasue AU - Yoshimi Bando AU - Sakae Homma AU - Koichi Hagiwara AU - Takafumi Suda AU - Naohiko Inase Y1 - 2022/09/01 UR - http://bmjopenrespres.bmj.com/content/9/1/e001337.abstract N2 - Background Diffuse pulmonary ossification is a specific lung condition that is accompanied by underlying diseases. However, idiopathic dendriform pulmonary ossification (IDPO) is extremely rare, and the clinical features remain unclear. In this study, we aimed to report the clinical characteristics of IDPO.Methods We conducted a nationwide survey of patients with IDPO from 2017 to 2019 in Japan and evaluated the clinical, radiological, and histopathological findings of patients diagnosed with IDPO.Results Twenty-two cases of IDPO were identified. Most subjects (82%) were male, aged 22–56 years (mean (SD), 37.9 (9.1)) at diagnosis. Nearly 80% of the subjects were asymptomatic, and the condition was discovered during a medical check-up. However, 36% of the subjects showed a decline in forced vital capacity (%FVC) predicted <80% at diagnosis. The typical radiological features of high-resolution CT (HRCT) are calcified branching structures that are predominantly distributed in the lower lung fields without any other conspicuous finding. Histopathological analysis also showed dendriform ossified lesions from the intraluminal areas to interstitial areas. Notably, during the follow-up period of 20 years, disease progression was found in 88% on HRCT and more than 50% on pulmonary function tests (FVC and/or forced expiratory volume in 1 s). Two cases with rapid decline of 10% /year in %FVC predicted were observed.)) at diagnosis. Nearly 80% of the subjects were asymptomatic, and the condition was discovered during a medical check-up. However, 36% of the subjects showed a decline in forced vital capacity (%FVC) predicted <80% at diagnosis. The typical radiological features of high-resolution CT (HRCT) are calcified branching structures that are predominantly distributed in the lower lung fields without any other conspicuous finding. Histopathological analysis also showed dendriform ossified lesions from the intraluminal areas to interstitial areas. Notably, during the follow-up period of 20 years, disease progression was found in 88% on HRCT and more than 50% on pulmonary function tests (FVC and/or forced expiratory volume in 1 s). Two cases with rapid decline of 10% /year in %FVC predicted were observed.Conclusions IDPO develops at a young age with gradually progressive phenotype. Further research and long-term (>20 years) follow-up are required to clarify the pathogenesis and clinical findings in IDPO.All data relevant to the study are included in the article or uploaded as online supplemental information. ER -