Diffuse pulmonary ossification and its association with cicatricial organising pneumonia in idiopathic and secondary forms

• Published in: Scientific reports Vol. 15; no. 1; pp. 12442 - 13
• Main Authors: Terasaki, Yasuhiro, Nishioka, Yasuhiko, Kajimoto, Yusuke, Toyoda, Yuko, Hebisawa, Akira, Johkoh, Takeshi, Egashira, Ryoko, Hisada, Takeshi, Mineshita, Masamichi, Baba, Tomohisa, Fujikura, Yuji, Kato, Motoyasu, Ichikado, Kazuya, Inoue, Yoshikazu, Izumi, Shinyu, Hasegawa, Yoshinori, Handa, Tomohiro, Hidaka, Koko, Hisata, Shu, Honjo, Chisato, Kishimoto, Takumi, Okamoto, Masaki, Yamasue, Mari, Terasaki, Mika, Suda, Takafumi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.04.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 692/308; 692/420; 692/699; Adult; Aged; Aged, 80 and over; Bone growth; Cicatricial organising pneumonia; Cryptogenic Organizing Pneumonia - complications; Cryptogenic Organizing Pneumonia - pathology; Dendritic pulmonary ossification; Diffuse pulmonary ossification; Female; Fibrosis; Humanities and Social Sciences; Humans; Idiopathic diffuse pulmonary ossification; Japan - epidemiology; Lesions; Lung - diagnostic imaging; Lung - pathology; Lung Diseases - pathology; Lung nodules; Lungs; Male; Middle Aged; Mortality; multidisciplinary; Ossification; Ossification (ectopic); Ossification, Heterotopic - complications; Ossification, Heterotopic - diagnostic imaging; Ossification, Heterotopic - pathology; Osteogenesis; Pathogenesis; Pneumonia; Pneumonia - pathology; Science; Science (multidisciplinary); Secondary diffuse pulmonary ossification; Japan; Cicatricial organising pneumonia; Dendritic pulmonary ossification; Secondary diffuse pulmonary ossification; Diffuse pulmonary ossification; Idiopathic diffuse pulmonary ossification
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-025-95307-0

Diffuse pulmonary ossification (DiPO) is characterised by widespread ectopic bone formation in the lungs. Idiopathic DiPO (I-DiPO) poses significant diagnostic challenges and its ossification mechanism remains unclear. Cicatricial organising pneumonia (CiOP) lesions form fibrous nodules without damaging lung structure. We investigated the histopathological features of I-DiPO, focusing on the surrounding fibrosis, and compared them with those of secondary DiPO (S-DiPO). An analysis was conducted using data from a nationwide DiPO survey in Japan. The dataset included clinical, radiological, and histopathological data of patients with suspected I-DiPO. The specific patterns of ossification and fibrotic findings such as CiOP, organising pneumonia (OP), and subpleural fibrosis were identified. Eighteen and seven patients were classified as having I-DiPO and S-DiPO, respectively. I-DiPO affects younger patients, progresses slowly, commonly occurs in the lower lungs, and has a lower mortality rate. S-DiPO affects older patients, presents with widespread lung lesions, and has a higher mortality rate. CiOP lesions were found in direct continuity with or near ossified lesions in 61.1% and 71.4% of patients with I-DiPO and S-DiPO, respectively. OP, CiOP, and ossified lesions often observed in the same locations in S-DiPO. DiPO has a unique pathogenesis, with an ossification transition occurring via the CiOP lesions. These findings provide valuable insights for future diagnostic approaches and management strategies for this condition.