CT findings in severe thoracic sarcoidosis

Abstract

Severe thoracic sarcoidosis includes manifestations with significant clinical and functional impairment and a risk of mortality. Severe thoracic sarcoidosis can take on various clinical presentations and is associated with increased morbidity. The purpose of this article was to describe the CT findings in severe thoracic sarcoidosis and to explain some of their mechanisms. Subacute respiratory insufficiency is a rare and early complication due to a high profusion of pulmonary lesions. Chronic respiratory insufficiency due to pulmonary fibrosis is a frequent and late complication. Three main CT patterns are identified: bronchial distortion, honeycombing and linear opacities. CT can be helpful in diagnosing some mechanisms of central airway obstruction such as bronchial distortion due to pulmonary fibrosis or an extrinsic bronchial compression by enlarged lymph nodes. An intrinsic narrowing of the bronchial wall by endobronchial granulomatous lesions may be suggested by CT when it shows evidence of bronchial mural thickening. Pulmonary hypertension usually occurs in patients with end-stage pulmonary disease and is related to fibrotic destruction of the distal capillary bed and to the resultant chronic hypoxemia. Several other mechanisms may contribute to the development of pulmonary hypertension including extrinsic compression of major pulmonary arteries by enlarged lymph nodes and secondary pulmonary veno-occlusive disease. Aspergilloma colonization of a cavity is the main cause of hemoptysis in sarcoidosis. Other rare causes are bronchiesctasis, necrotizing bronchial aspergillosis, semi-invasive pulmonary aspergillosis, erosion of a pulmonary artery due to a necrotic sarcoidosis lesion, necrosis of parenchymal sarcoidosis lesions and specific endobronchial macroscopic lesions.

Clinical presentations and diagnostic work-up in sarcoidosis: a series of Turkish cases (clinics and diagnosis of sarcoidosis)

“…In the present study, only in 2.4% of the patients CT was not performed. Even for the severe pulmonary sarcoidosis patients, CT scan is the most accurate technique to thoroughly assess the complications: it allows to detect them, to make clear their underlying mechanisms and subsequently to help the clinicians in their approach to the therapy and the prognosis of patients (17). In the present study, the most common CT appearance was mediastinal lymphadenomegaly, followed by nodules and reticular infiltrations.…”

“…The low frequency of diffuse fibrosis and honey combing was consisted with very low frequency of Stage IV sarcoidosis patients. In the absence of fibrosis, localized bronchiectasis may rarely develop downstream from a bronchial obstruction, secondary to either endobronchial sarcoid or extrinsic compression by enlarged nodes (17). The 3% ratio for bronchiectases may reflect that the less severe forms of disease had the predominancy in the recent series of sarcoidosis.…”

Pulmonary sarcoidosis: a case report with typical imaging features

“…Computed tomographic scan is ahead of conventional chest radiographs in depicting parenchymal, mediastinal and hilar abnormalities 10 . On CT scan, the typical features of sarcoidosis is mediastinal and/ or hilar lymphadenopathy, nodular opacities and micronodules along bronchovascular bundles, predilection for mid and upper lung zones, an axial distribution, pleural or subpleural nodules, septal and nonseptal lines, confluent nodular opacities with consolidation and groundglass opacities11.…”

Chest Computed Tomography-Based Scoring of Thoracic Sarcoidosis: Inter-rater Reliability of CT Abnormalities

“…A multitude of abnormalities can be detected [1][2][3][4], but little is known about inter-rater agreement. There appears to be good reported agreement between raters in scoring a limited number of abnormal CT findings in sarcoidosis with kappa values ranging from 0.81 to 0.89.…”