Fig. 2
Cytomorphology of epithelioid mesothelioma cells and tissue fragments in effusions. The tissue fragments sometimes show gaps or windows (a, b), and occur both as spheres with smooth surfaces (c, d) and in berry-like clusters with scalloped surfaces (e, f). The tissue fragments may contain acidophilic extracellular matrix cores, also known as collagen or basement membrane cores (g, h), which with MGG become strongly acidophilic, similar to the extracellular granular material that can be seen in the background (see also f and fig. 1), indicating large amounts of hyaluronan. a, c, e, g Pap stain. b, d, f, h MGG stain. Scale bar = 50 μm.