Fig. 4

Immunohistochemical features of the tumor. The acinic component was negative for ER (A, EnVision, 200×). Collagen type IV (B, EnVision, 200×) staining revealed the absence of basement membrane around the neoplastic glands and solid nests and the presence of capillaries. And α1-antitrypsin (AAT) (C, EnVision, 200×), lysozyme (LYS) (D, EnVision, 200×), Epithelial membrane antigen (EMA) (E, EnVision, 200×), CK (AE1/AE3) (F, EnVision, 200×), S100 (G, EnVision, 200×), and GATA3 (H, EnVision, 200×) were expressed merely in the acinic component, but their expression was absent in the high-grade lesion. Cyclin D1 (I, EnVision, 400×) showed diffuse expression, and the Ki-67 labeling index (J, EnVision, 200×) was 95% in the high-grade lesion. Vimentin (K, EnVision, 200×) showed diffusely positive expression, and p53 (L, EnVision, 400×) staining was approximately 80% positive in the high-grade area