Fig. 2.

(a) Low power photomicrograph of the tumor showing cells arranged in fascicles as well as haphazard pattern with edematous background and admixed inflammatory cells. (b) High power picture showing spindle cell population exhibiting myofibroblastic differentiation with mild to moderate nuclear pleomorphism, finely dispersed chromatin and moderate to abundant cytoplasm. The inflammatory cells are rich in plasma cells with lymphocytes and few eosinophils (H&E 200x). (c) Immunostain for ALK-1 showing nuclear reactivity in cells with myofibroblastic differentiation. (d) Immunostain for SMA showing cytoplasmic reactivity in cells with myofibroblastic differentiation.