Clinical and morphological characteristics of mediastinal lymphadenopathy in granulomatous pulmonary diseases

Abstract

The purposeof this study was to determine detection rate and clinical and morphological characteristics of mediastinal lymphadenopathy (ML) in patients with respiratory system sarcoidosis (RSS), disseminated pulmonary tuberculosis (DPT) and exogenic allergic alveolitis (EAA).Materials and Methods.Patients (n= 278) with established diagnosis RSS, DPT, EAA were investigated. The cumulative index parameters were determined, hematology test, assessments of pulmonary function, diffuse lung capacity, diffusion coefficient were performed in all patients. Computed tomography of chest organs and morphologic examination of mediastinal lymph node (LN) biopsy were performed.Results.Subjects with newly diagnosed (n= 72) and recurrent (n= 104) disease were observed among patients with RSS (n= 176). ML was observed in 95% of cases, involved bronchopulmonary, bifurcation, paratracheal and paraaortal groups; dimensions of intrathoracic LN (ITLN) were 20.0 ± 1.9 mm. Epitheliocellular granulomas (EG) without necrosis, not fusing with each other, were established morphologically; they were determined in recurrent disease course in association with background fibrosis. In patients with DPT (n= 41), subacute (n= 28) and chronic (n= 13) disease course was noted. With subacute course of DPT in 28.6% of cases, ML of paratracheal and bifurcation groups (dimensions of ITLN – 13.1 ± 0.3 mm) was observed, with chronic course – the enlargement of paratracheal and bronchopulmonary LN (7.7% of cases). EG with necrosis and tendency to fusion was verified histologically; inflammatory process involved LN capsule and could be spread to fatty tissue. In patients with EAA (n= 76), acute (n= 10), subacute (n= 38) and chronic (n= 28) disease courses were observed. With acute EAA course, hyperplasia of ITLN of bifurcation and tracheo-bronchial groups up to 13.5 ± 0.6 mm was observed in 20% of cases. Follicular hyperplasia with widening and edema of hermintative centers was observed at morphological investigation. With subacute EAA course, increased ITLN in bifurcation and broncho-pulmonary groups up to 13.6 ± 0.6 mm were observed in 46% of cases. Formation of histiocytic-macrophagal granulomas without epithelioid cells and deposit precipitation in the plasma cell aggregation areas was found at morphological evaluation. With chronic EAA, ML in broncho-pulmonary and paratracheal groups was detected in 17.8% of cases (enlargement of LN up to 11 ± 0.9 mm). The formation of diffuse and focal fibrosis and hyalinosis was noted morphologically.Conclusion.ML is observed in all granulomatous pulmonary diseases studied, however its rate and severity, composition of involved ITLN groups and character of morphological changes is different which is possible to use in diagnostics.