SMN1 and inflammatory myofibroblastic tumor: In this case, immunohistochemical staining was positive for SMA (Fig. 4B), partially positive for desmin, and positive for KP-1 (Fig. 4C), but negative for CD34, CK (AE1/AE3), and CK (CAM5.2), with an MIB-1 index of <10% (Fig. 4D) and ALK positivity (Fig. 4E), confirming the diagnosis of IMT (Table 1).