Comparison of clinical features and prognosis in patients with cryptogenic and secondary organizing pneumonia

Abstract

Background Organizing pneumonia (OP) can be diagnosed pathologically, and cryptogenic OP (COP) and secondary OP (SOP) have been classified by cause and particular underlying context. Because it is clinically difficult to differentiate between COP and SOP, this study investigated characteristics that could distinguish between COP and SOP. Methods The medical records of patients who underwent lung biopsy for a diagnosis of OP at a single tertiary hospital from January 2016 to December 2018 were retrospectively reviewed. Results Eighty-five patients had pathologically proven OP, including 16 diagnosed with COP and 69 diagnosed with SOP. The most common cause of SOP was infectious pneumonia, observed in 57 (82.6%) of the 69 patients, followed by cancer and radiation pneumonitis. The pathogens causing infectious pneumonia were identified in 45 (65.2%) patients. There were no differences in age, sex, and lung function between the COP and SOP groups. Median body mass index was significantly lower (P = 0.030), and median time from symptom onset to hospital admission significantly shorter (P = 0.006), in the SOP than in the COP group. Fever was more common in the SOP group (P = 0.024), and CURB 65, an index of pneumonia severity, tended to be higher in the SOP group (P = 0.017). Some laboratory results differed significantly between the two groups. Lymphocyte counts in bronchoalveolar lavage (BAL) fluid were significantly higher in the COP than in the SOP group (P = 0.012). Radiologic findings showed that effusion was more common in the SOP group (P = 0.036). There were no between-group differences in steroid use, 30 day and in-hospital mortality rates, and rates of OP outcomes and recurrences. Pneumonia recurrence rate was significantly higher in SOP patients who were than were not treated with steroids (P = 0.035). Conclusions Infection is the main cause of SOP. Symptom onset is more rapid in patients with SOP than with COP. Some blood and BAL fluid test results differed significantly in the COP and SOP groups. Pleural effusion was more common in the SOP group but there were no differences in clinical course. Recurrence in patients with SOP was more common in those who were than were not treated with steroids.

Can Ultrasound and Contrast-Enhanced Ultrasound Help Differentiate between Subpleural Focal Organizing Pneumonia and Primary Lung Malignancy?

“…However, due to the long-term existence of chronic inflammation, the bronchial wall may be damaged, or the bronchiole cavity may be completely filled with inflammatory cells or liquid, resulting in the loss of the echo interface; therefore, two-dimensional ultrasound images do not show air bronchial signs. PLM shows infiltrative growth, invades and destroys the bronchial tube wall, and generally does not show air bronchial signs [ 8 , 9 ]. However, the mass compressed the tracheal cavity wall, which blocked the distal bronchus.…”

“…High-resolution computed tomography (CT) is the recommended imaging technique for the diagnosis, assessment, and follow-up of OP [ 3 ]. CT presentation of OP is polymorphous, but a few patterns have recently been recognized as being more specific to this diagnosis, such as the burr sign, lobulation sign, bronchial inflation sign, and pleural indentation sign [ 8 , 9 , 10 ]. These signs are not unique to FOP, and there are a few overlapping signs between FOP and peripheral lung malignancy (PLM) on chest CT scans [ 11 , 12 ].…”

Delayed-onset Organizing Pneumonia Emerging after Recovery from Coronavirus Disease 2019: A Report of Three Cases Diagnosed Using Transbronchial Cryobiopsy and a Review of the Literature

“…Influenza-induced SOP may occur 2-3 weeks after the onset of viral infection ( 14 ). In a study of SOP due to various causes, including infectious diseases, the median time from the onset to hospitalization was 1 week, which is significantly shorter than cryptogenic OP ( 21 ). In our cases, the manifestation of symptoms in the form of OP occurred 31-34 days after the onset of COVID-19, which seems to be longer than SOP caused by other infections.…”

Cryptogenic Organizing Pneumonia Complicated With Cutaneous Disseminated Nocardia Infection: A Case Report and Literature Review

“…Among them, solid deformation is the most common type, the CT manifestation is patchy solid deformation, which is mainly distributed under the pleura or/and along with the bronchial vascular bundle. The bronchial gas phase is seen in some parts, and both sides are common ( 17 ). The common imaging manifestations of Nocardia pneumonia are nodule/mass shadow, ground glass shadow, interlobular septal thickening, cavity, consolidation, bronchiolitis, bronchial wall thickening, mediastinal lymph node enlargement, local pleural thickening, and rare air bronchogram.…”