Greater pulmonary fibrosis percentage measured by computer-aided detection at preoperative CT is an independent predictor of worse disease-free survival in patients with lung cancer. BackgroundInterstitial lung abnormalities (ILAs) are present at CT in about 10% of individuals undergoing lung cancer screening. The relationship between histologic findings of ILAs and their influ...

The presence of a lung lesion is common in microscopic polyangiitis (MPA), and interstitial lung disease (ILD) can lead to a poor prognosis. Although myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) are often present in patients with MPA, patients with ILD and MPO-ANCA positivity but without other manifestations of systemic vasculitis have also been reported. Therefore, the possible association between MPO-ANCA, MPA, and idiopathic ILD remains unclear. This problematic matter has influenced the treatment strategy of MPO-ANCA-positive ILD patients without systemic vasculitis. Clinicians should undertake treatment with careful consideration of the four major causes of death in MPO-ANCA-positive ILD: acute exacerbation of ILD, progressive lung fibrosis, infectious comorbidities, and diffuse alveolar hemorrhage. Further, clinicians need to carefully judge whether inflammation or fibrosis is the dominant condition with reference to the patient’s clinical domain and radiopathological lung features. Recently, anti-fibrotic agents such as nintedanib and pirfenidone were shown to be effective in treating various etiologies associated with ILD and have thus led to the widening of treatment options. In this review, the clinical characteristics, radiopathology, prognosis, and therapeutic options in patients with MPO-ANCA-positive ILD are summarized using limited information from previous studies.

Pleuroparenchymal fibroelastosis (PPFE) is characterized by fibrosis involving the pleura and subpleural lung parenchyma, predominantly in the upper lobes. As PPFE appears to occur in patients with heterogeneous etiologies, the disease course is thus also heterogenous, with some patients showing rapid progression while others have slow progression. Therefore, it is very difficult to predict prognosis with PPFE. Needless to say, this problematic matter has influenced the treatment strategy of PPFE patients. In fact, until now no evidence has been shown for use in creating an appropriate management algorithm for PPFE. We speculate that “uncoordinated breathing” is the most important reason for dyspnea in PPFE patients. Because monitoring of physique and not just pulmonary function and radiological evaluation is also very important, particularly in PPFE patients, this review focused on the characteristics of PPFE through an overview of previous studies in this field, and we proposed an algorithm as precision medicine based on the current evidence. Multiple views by the pulmonologist are needed to standardize a clinical algorithm that is necessary to correctly assess PPFE patients under the premise of maintenance of physique by providing appropriate nutritional care and pulmonary rehabilitation.

Chronic obstructive pulmonary disease (COPD) is a major comorbid disease of Mycobacterium avium complex pulmonary disease (MAC-PD). Emphysema is one of the main pathological findings in COPD, a risk factor for chronic pulmonary aspergillosis (CPA), and is associated with poor prognosis. We aimed to clarify the effect of emphysema on mortality in MAC-PD. We retrospectively analyzed 203 patients with MAC-PD at The Jikei Daisan Hospital between January 2014 and December 2018. We investigated the mortality and CPA development rates after MAC-PD diagnosis in patients with or without emphysema. Multivariate Cox proportional hazards regression analysis showed the following negative prognostic factors in patients with MAC-PD: emphysema (hazard ratio [HR]: 11.46; 95% confidence interval [CI]: 1.30-100.90; P = 0.028); cavities (HR: 3.12; 95% CI: 1.22-7.94; P = 0.017); and low body mass index (<18.5 kg/m²) (HR: 4.62; 95% CI: 1.63-13.11; P = 0.004). The mortality and occurrence of CPA were higher in MAC-PD patients with than without emphysema (log-rank test, P < 0.0001 and P < 0.0001). Our study findings showed that emphysema detected by computed tomography was associated with an increased risk of CPA development and mortality in MAC-PD.

Background and purpose: Idiopathic dendriform pulmonary ossification (DPO) is mostly asymptomatic, and detected incidentally in lung CT. There have been no reports on the precise CT–pathologic correlation and the prevalence of idiopathic DPO. This study aimed to clarify the histological background and prevalence of idiopathic DPO. Materials and methods: Sixteen patients with histologically confirmed idiopathic DPO (12 men and 4 women; mean age, 38.8 years; range 22–56 years) were identified in a nationwide epidemiological survey. Local HRCT findings of pre-biopsy examinations, such as branching, round, linear structures with or without high attenuation were compared side by side with histological findings. The attenuation of branching, round, and linear structures was classified into three-point levels on bone window images (width, 2500 HU; level, 500 HU). Furthermore, we collected continuous pulmonary CT images of 8111 cases for checking up metastasis from extrathoracic malignancy at a single institution, and evaluated the prevalence of interstitial lung abnormalities (ILAs) and DPO. Results: In all 16 cases, branching (n = 15, 93%), round (n = 5, 31%), or linear (n = 5, 31%) structures were identified, histologically corresponding to dendriform ossification and cicatricial organizing pneumonia (OP)/fibrosis. Histologically, ossification was confirmed in all the 16 patients. However, in two cases, a highly attenuated structure could not be detected on the pre-biopsy CT of the same area. Regarding the prevalence of idiopathic DPO, 283 (3.5%) of 8111 patients had ILAs, of which a total of 26 (0.3% of all cases, 9.2% of ILAs cases) had DPO. Conclusion: Idiopathic DPO showed linear or branching structures with or without high attenuation on CT, corresponded to ossification, cicatricial OP/fibrosis. DPO was seen in 9.2% of ILAs cases. Idiopathic DPO is one of pathologic phenotypes of ILAs.