Case Report

Inflammatory Myofibroblastic Tumour of the Skull Base

Figure 2

(a) HES × 10: a dense proliferation of spindle cells, partly with an epithelioid aspect, arranged in well-organized fascicles suspended in a myxoid background and admixed with many inflammatory cells, mostly lymphocytes, plasma cells, eosinophils, and rare mast cells. (b) HES × 20: spindle cells present with few atypical features: prominent nucleolus, anisokaryosis, and modest mitotic activity. (c) immunostaining with smooth muscle actin (SMA): spindle cells present a cytoplasmic and diffuse positivity with SMA. (d) immunostaining with CD45 (antipanleukocytes) exhibits the significant lymphoplasmacytic population. FISH analysis was performed: no rearrangement for ALK-1 gene was noticed.
103646.fig.002a
(a)
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(b)
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(c)
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(d)