Figure 3

Immunohistochemical findings and fluorescence in situ hybridization (FISH) studies. The spindle cells were positive for vimentin (A), α-smooth muscle actin (B), and anaplastic lymphoma kinase-1 (ALK-1) (C) (immunohistochemistry staining × 200). (D) FISH studies demonstrated rearrangements of the ALK gene with split of the red and green signals (arrows) in the spindle cells.