Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease classified as idiopathic interstitial pneumonia. High resolution computed tomograph (HRCT) and histologic examination of open lung biopsy are tools to recognise a subset of patients IPF with interstitial pulmonary fibrosis, i.e.the usual interstitial pneumonia (UIP). HRCT increases the level of diagnostic confidence of UIP and is used for quantification of the disease extent. Surgical lung biopsy allows to distinguish UIP from other processes that mimic IPF and is recommended in patients suspected IPF. The aim of this study was to compare the degree morphologic patterns with HRCT images, and to investigate the usefulness of histopathology and HRCT in order to estimate the prognosis. All in all, 14 symptomatic patients: 8 with UIP and 6 with IPF entered this retrospective analysis. The HRCT examination was based on a 3 point scale: 1/ ground glass pattern (ggp) more extensive than reticular pattern (rp); 2/ ground glass pattern of equal intensity with reticular pattern; 3/ grond glass pattern more extensive than reticular pattern. The diagnosis of UIP was made separately with a high and low degree of confidence based on HRCT appearance. Lung biopsy specimens were staged according to the morphologic pattern into: early, late and mixed UIP. The clinical re-assessment based on HRCT and/or pathology reports and patients follow up formed the final diagnosis of UIP in 12/14 patients. In one patient a desquamative interstitial pneumonia was confirmed, and one patient showed features of non-specific chronic interstitial lung disease. A correlation between the histopathologic features and HRCT images was found in 58% (7 out of 12 patients) with UIP. These patients presented grade 2 or 3 HRCT patterns and were properly sampled for histologic examination, which confirmed more advanced stages of the disease. The discrepancy between more advanced morphologic pattern and less advanced HRCT grade occurred in 2 /12 patients, and was caused by non representative lung biopsy samples. Inadequate site or size of lung biopsy samples for UIP caused a discordance in three other patients. The clinical extent, rate of progression and response to applied therapy of UIP patients varied markedly and made the correlation between clinical progression of the disease and HRCT or histopathologic findings difficult. We conclude that for an accurate diagnosis and optimal management of UIP patients, the histologic examination is valuable. However, it is highly dependend on proper lung biopsy sampling. HRCT scanning is a reliable method for UIP diagnosis especially in more advanced stages and can replace an open lung biopsies in typical UIP cases.
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