Fig. 2.
a Low-power view of the initial pleural biopsy being consistent with chronic pleuritis with lymphocytic inflammation (a, HE, ×5). b High-power view of the initial pleural biopsy, highlighting a single layer of cuboidal mesothelial cells, without frank atypia at the surface of the pleura (b, HE, ×20). c Low-power view of the invasive pleural mesothelioma with infiltration of the lung parenchyma (c, HE, ×5). d, e Complete loss of MTAP in the neoplastic mesothelial cells by IHC. Retained MTAP expression in adjacent lymphocytes and stromal cells (d, e, HE, ×20).