Possible Estrogen Dependency in the Pathogenesis of Branchial Cleft Cysts

Figure 4

Immunohistological staining (20x). (a) Nuclear expression of estrogen receptor alpha in the basal and middle layer of the squamous epithelium lining a branchial cleft cyst arising in a pregnant female patient. (b) Strong nuclear expression of Ki-67 (40x) in the entire basal layer as well as focal expression in the middle layer of the epithelium (arrow).

(a)

(b)