Comparison of β-Catenin and LEF1 Immunohistochemical Stains in Desmoid-type Fibromatosis and its Selected Mimickers, With Unexpected Finding of LEF1 Positivity in Scars.

Summary

β-catenin immunohistochemical stain can be useful in the diagnosis of many tumors including desmoid-type fibromatosis (DTF). Lymphoid enhancer-factor 1 (LEF1), a recently emerged marker, is part of the Wnt pathway with β-catenin but has not been studied in DTF. We performed LEF1 and β-catenin immunohistochemistry in DTF (n=26), superficial fibromatosis (n=19), sclerosing mesenteritis (n=12), gastrointestinal stromal tumor (n=17), and cutaneous scar (n=14) using tissue microarray and whole sections.  In conclusion, this study demonstrated that LEF1 may be a useful marker in the differential diagnosis of DTF in certain contexts. However, caution should be exercised since LEF1 positivity can also be seen in scars.