Nationwide retrospective observational study of idiopathic dendriform pulmonary ossification: clinical features with a progressive phenotype.

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.

Correlation among the indices of high-resolution computed tomography, pulmonary function tests, pulmonary perfusion scans and exercise tolerance in cases of chronic pulmonary emphysema.

BACKGROUND: Mismatched distribution of pulmonary blood flow is a common characteristic in emphysematous patients. But few reports have mentioned the relationships between the morphological changes in the lungs as assessed by high-resolution computed tomography (HRCT), pulmonary blood flow (PBF) scan and the indices of exercise tolerance. We investigated these relationships. OBJECTIVE: Pulmonary function tests (PFT), HRCT, single photon emission computed tomography ((99m)SPECT) and treadmill exercise tests were performed on emphysematous patients, and the correlations between these examinations were studied. METHODS: We evaluated 20 patients (M 18, F 2, age 66 +/- 8.0 years). CT evaluation was performed according to the grade of emphysematous change. (99m)SPECT was performed to evaluate mismatched PBF by the score method. The better flow of the middle lobe was selected to be the standard lobe for the basic PBF. That score was set to 1 when the blood flow was below 60 or above 140%. PBF between 60 and 140% was scored as 0. RESULTS: FEV(1 )(r = 0.648, p = 0.002) and VC (r = 0.767, p = 0.001) correlated significantly with Vdot;O(2) peak. FEV(1) (r = 0.667, p = 0.0018) correlated significantly with anaerobic threshold (AT). CT grade did not correlate with PBF mismatch score (r = 0.266, p = 0.3376). %Vdot;O(2 )peak did not correlate with CT grade (r = -0.467, p = 0.0689) or with mismatch PBF score (r = -0.327, p = 0.2377). CONCLUSIONS: HRCT and (99m)SPECT were advantageous for detecting the progression of disease and emphysematous changes. However, the severity of anatomical emphysematous changes did not necessarily correlate with the indices of exercise tolerance and pulmonary function tests.