Figure 2. (a): Low-power photomicrograph of the tumour showing cells arranged in fascicles and a haphazard pattern with an oedematous 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 oeosinophils (H&E 200×). (c): Immunostain for ALK-1 on D5F3 Ventana platform showing diffuse nuclear reactivity in 100% of the tumour cells with myofibroblastic differentiation. (d): Immunostain for SMA showing cytoplasmic reactivity in cells with myofibroblastic differentiation.