Table 1. Immunohistochemical characteristics are useful in the differential diagnosis of inflammatory myofibroblastic tumor (IMT) differential diagnosis.
| Diagnosis | Immunohistochemical features | References | ||||||
|---|---|---|---|---|---|---|---|---|
| ALK | CD117 | Desmin | SMA | CK AE1/AE3 | S100 | EMA | ||
| Inflammatory myofibroblastic tumor | +/− | – | +/− | + | +/− | – | −/+ | [11,53,61] |
| GIST | – | + | – | +/− | −/+ | – | −/+ | [29,105] |
| Rhabdomyosarcoma* | −/+ | – | + | + | +/− | – | – | [102,113] |
| Leiomyosarcoma | – | – | + | + | – | – | +/− | [94] |
| Schwannoma** | – | – | – | – | −/+ | + | −/+ | [33] |
| Solitary Fibrous Tumor*** | – | – | – | −/+ | – | – | −/+ | [114] |
| Fibromatosis**** | – | – | – | +/− | – | – | – | [62] |
| Squamous cell carcinoma# | – | – | – | – | + | – | + | [98,115–117] |
Note: ALK-anaplastic lymphoma kinase; CD117-differentiation 117; SMA-smooth muscle actin; CK AE1/AE3-Cytokeratin AE1/AE3; EMA-epithelial membrane antigen; *MyoD1 and myogenin positivity supports diagnosis; **Strong expression of S100 and SOX10 is required; ***STAT6 nuclear immunohistochemical expression or identification of STAT6 rearrangement in fluorescence in situ technique is important for the final diagnosis; ****B-catenin nuclear expression favors the fibromatosis diagnosis; #in routine diagnostics, expression of p40, p63, and CK 5/6 are typical for squamous cell carcinoma.