Interstitial Lung Disease Is Applicable to Tissue Microarray Analysis with Spiral Tissue Microarray Technique
R Ohsawa, T Tanaka, S Shimizu, Y Kashima, S Tominaga, T Hori, J Fukuoka. Toyama University Hospital, Toyama, Japan
Background: Interstitial lung disease (ILD) is a histologically heterogenous disease and composed of multiple combinations of histopathology. Unlike neoplastic disease, key findings of ILD is often a mixture of multiple histological events such as lymphocytic infiltration, epithelial reaction, fibrosis and vascular injury. Due to its uneven histological distribution, application to TMA study has been considered to be difficult. We have recently developed a novel tissue microarray (TMA) technique named Spiral TMA (S-TMA). S-TMA block can be constructed by embedding multiple reeled thick-cut specimens vertically to a designed recipient block. Its two biggest advantages are to cover tissue heterogeneity and skip damaging donor blocks. We created both conventional TMA (c-TMA) and S-TMA of ILD cases, and investigated if S-TMA can reasonably cover histological variations of ILD.
Design: Twenty five cases with ILD in the lobectomy specimen performed against primary lung cancer at Toyama University were collected. S-TMA was constructed with 100 micron thick sections of the blocks. c-TMA with 2mm cores was also constructed. Areas including best histology were carefully selected by a trained pathologist. Presence of bronchiolar epithelia, large pulmonary arteries (PA), lymphocytic infiltration, type II epithelia, airspace filling macrophage and fibrosis was examined in S-TMA, c-TMA, and whole HE slides of original blocks. Large PA was defined with presence of both internal and outer elastic layers which were confirmed by EVG staining. The degree of fibrosis was also confirmed by EVG staining.
Results: Areas seen in S-TMA ranged from 1.4 to 2.8mm2 (mean 2.04mm2), while those in c-TMA was always 3.14mm2. Each finding seen in S-TMA/c-TMA/whole original slides was as follows. Bronchiolar epithelia, 16/14/25; Large PA, 20/22/25; lymphocytic infiltration, 13/4/24; type II epithelia, 21/8/25; Airspace filling macrophages, 20/20/24 and fibrosis, 24/24/25.
Conclusions: S-TMA covered more of histological variations in ILD than c-TMA. Application of S-TMA on ILD cases may contribute accelerating upcoming molecular-expression studies in the area of ILD.
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 240, Monday Morning