Fig. 2

(A) H&E staining revealed that the inner layer of the tumor cyst wall was composed of basaloid tumor cells arranged in a palisade pattern, with focal comedo necrosis observed. The tumor tissue exhibited a mixed distribution of cystic and nested patterns. The tumor cells were moderately small with a high nucleus-to-cytoplasm ratio, displaying uniform basophilic staining (×40). (B) H&E staining indicated an orderly arrangement of tumor cells. No significant tumor cells were observed within the cyst cavity, and there were no notable nodules in the cyst wall. Outside the cyst cavity, there were no signs of tumor cells exhibiting papillary projections or invasive characteristics (×100). (C–F) (Immunohistochemistry), (C) showed strong positive reactivity of CK-pan. (D) showed strong positive reactivity of p63. (E) showed strong positive reactivity of p40. (F) showed weak positive reactivity of CD117