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Significant increases in the density and number of lymphatic vessels in pleuroparenchymal fibroelastosis
Author(s) -
Kinoshita Yoshiaki,
Watanabe Kentaro,
Ishii Hiroshi,
Kushima Hisako,
Fujita Masaki,
Nabeshima Kazuki
Publication year - 2018
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.13634
Subject(s) - lymphatic system , lymphatic vessel , pathology , medicine , lung , interquartile range , anatomy , cancer , metastasis
Aims Some investigators have detected fibrinous exudate or immature organisation in the alveolar spaces prior to the development of subpleural elastofibrosis in patients with pleuroparenchymal fibroelastosis ( PPFE ). We hypothesised that PPFE progress is associated with an impaired lymphatic drainage system, resulting in the failed resolution of intra‐alveolar exudate. The aim of this study is to investigate the pulmonary lymphatic vessels in PPFE , histologically. Methods and results We retrospectively reviewed our medical records from 1995 to 2017, and selected autopsied or surgically biopsied patients with PPFE ( n = 18), pulmonary apical cap ( n = 18), and IPF ( n = 26). We detected lymphatic endothelial cells by using immunostained specimens, calculating the percentage of lymphatic vessel area in the non‐aerated area (lymphatic vessel density) and the number of lymphatic vessels per non‐aerated area (per mm 2 ) (lymphatic vessel number). These parameters in PPFE were compared with those in apical cap, IPF , and normal lung tissue. The lymphatic vessel density in PPFE patients [2.97%; interquartile range ( IQR ) 2.61–3.86] was significantly higher than that in normal lung (0.91%; IQR 0.84–1.07), pulmonary apical cap (0.67%; IQR 0.58–0.83), and IPF (0.91%; IQR 0.68–1.25) ( P < 0.01 in any comparison). The lymphatic vessel number in PPFE was also significantly higher than that in normal lung, pulmonary apical cap, and IPF . Among PPFE patients, the increase in lymphatic vessel density was found to be correlated with the characteristic physiology of PPFE , such as a flattened chest cage on computed tomography and high residual volume/total lung capacity ratio on spirometry. Conclusions Significant increase in the density and number of lymphatic vessels is a supportive characteristic that enables the differentiation of PPFE from IPF and apical cap.