This study aimed to compare the expression of lymphoid enhancer factor 1 (LEF1) and β-catenin in basal cell adenoma (BA), desmoid-type fibromatosis (DF), and pancreatic solid pseudopapillary neoplasm (SPN) to evaluate their diagnostic utility in tumors associated with the WNT/β-catenin signaling pathway harboring the mutation of CTNNB1 gene 3 exon. The gene discussed is LEF1; the disease is desmoid tumor.