Figure 2.

Inflammatory myofibroblastic tumor. 2a: Spindle cell lesion with more regular pattern than in 1a, myxoid degeneration, vessels similar to granulation tissue, infiltration with inflammatory cells (HE ×200). 2b: Lack of atypia in tumor cells, resembling regular myofibroblasts (HE ×400). 2c: Diagnostic expression of ALK-1 immunoperoxidase (×400). 2d: Low proliferation (Ki67), less 10% (immunoperoxidase ×400). 2e: Relapse tumor, sharply confined surfaced with intact epithelium (HE ×40). 2f: Higher cellularity, no myxoid changes, less inflammatory cells, but mild atypia in the relapse (HE ×400).