Fig. 2.

(A) A well-demarcated tumor composed of basaloid lobules surrounded by a pseudocapsule in the deep dermis (H&E, ×40). (B) Distinctive 'cell balls' of pale cells with peripheral condensation (H&E, ×200). (C) Keratinous microcysts (arrow) are located in the eccentric part of the cell ball. The tumor cells extending from lobules make anastomosing strands or buds (H&E, ×400). (D)The peripheral rim of the cell balls were prominently stained with anti-CK5/6, whereas the centrally located pale 'cell balls' expressed weaker staining with anti-CK5/6 (avidin-biotin complex, ×200)