Reticular opacity-to-ground glass opacity ratio: one or greater Reticular opacities: in the immediate subpleural lung, often associated with honeycombing and traction bronchiectasis, with peripheral and lower lobe predominance, is considered a very good differentiating feature from patients with NSIP and concurrent emphysema 2 Those with less than 5% honeycombing may pose diagnostic difficulty as differentiation from NSIP on imaging can be impossible however, these still follow similar prognosis as other UIP patients 2 It mainly reflects the stage and severity of the disease. In general, UIP can be divided into two groups, those with 5% honeycombing. Honeycombing: particularly if it involves more than 5% of the lung parenchyma, is highly specific for UIP. When describing imaging features, the term UIP pattern is often used, which has specific diagnostic criteria on HRCT 16. The positive predictive value of CT in the diagnosis of UIP is high and ranges from 70-100% 1. Similar to the pathology specimen, cross-sectional imaging also reveals heterogeneity, with patchy areas of fibrosis alternating with areas of normal lung 5. Usually, due to the more extensive involvement of the lower lobes, the major fissure is shifted inferiorly which is best seen on the lateral chest radiograph. While chest radiographs can be even normal in patients with very early disease, in advanced disease, it may show decreased lung volumes and basal fine to coarse reticulation. In practice, the diagnosis is usually made in a multidisciplinary approach involving chest physicians, radiologists and pathologists with expertise in interstitial lung disease 12. Medications/drug toxicity: amiodarone lung Mixed connective tissue disease: either a UIP or NSIP pattern 4Īsbestos-related interstitial lung disease: asbestosis 1 Polymyositis/ dermatomyositis: a UIP, NSIP, or c ryptogenic organizing pneumonia pattern 4 Systemic sclerosis (scleroderma): either a UIP or NSIP (more common) pattern 4 Rheumatoid arthritis: UIP is considered to be the dominant pattern in those with rheumatoid arthritis who have concurrent interstitial lung disease 3 These would include:Ĭonnective tissue disorders (CTD associated UIP): falls under the broader spectrum of connective tissue disorder interstitial lung disease (CTD-ILD) UIP pattern of interstitial lung disease can be seen in idiopathic pulmonary fibrosis or secondary to underlying systemic diseases. Inflammation is absent or mild and mostly limited to the areas of honeycombing 1-12. The distribution of UIP characteristically is with an apicobasal gradient with basal and peripheral (subpleural) predominance, although it is often patchy. Honeycombing, particularly if it involves more than 5% of the lung volume, is an almost 100% specific finding. On a typical biopsy, there are areas of normal lung alternating with interstitial fibrosis and honeycombing. The histological diagnosis of UIP is based on temporal and spatial heterogeneity, which is the identification of fibrotic lesions at different stages (fibroblastic infiltrates, mature fibrosis, and honeycombing) within the same biopsy specimen and architectural distortion.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |