Clear cell carcinoma of the gynecologic tract has been defined in terms of
its clinical and histologic features; however, its immunophenotypic profile
has not been fully characterized. Seventeen cases of primary clear cell ca
rcinoma from various sites within the female genital tract (11 ovary, 5 ute
rus, 1 vagina) were analyzed by immunohistochemistry. These turners were as
sessed for the expression of cytokeratin 7 (CK7), cytokeratin 20 (CK20), lo
w and high molecular weight cytokeratins (CAM5.2 and 34 beta E12, respectiv
ely), carcinoembryonic antigen (CEA), Leu-MI, vimentin, estrogen receptor (
ER), progesterone receptor (PR), bcl-2, p53, HER-2/neu, and CA-125. The cha
racteristic immunoprofile for all sites was positivity fur CK7, CAM5.2, 34
beta E12, CEA, Leu-Ml, vimentin, bcl-2, p53, and CA-125; variably positivit
y for ER and HER-2/neu; and negativity for CK20 and PR. For comparison, two
cases of urologic clear cell carcinoma (1 bladder, I urethra) were also st
udied, and their profile was found to be similar to the gynecologic cases.
Aside from minor differences, clear cell carcinoma appears to have the same
immunophenotype regardless of whether it originates in the endometrium, ov
ary, or genitourinary tract. Much of its profile is similar to other gyneco
logic adenocarcinomas, but some of the markers studied may be useful in the
differential diagnosis of this tumor.