At low magnification, one can see the pointed or blunt finger-like papillary projections lined by pseudostratified columnar epithelium and enclosing delicate fibroascular stroma.

• 低倍镜下，可见其表面呈绒毛状或细乳头状突起。肿瘤表面覆盖一层假复层柱状上皮，包绕着纤维血管基质。