PAX8 discriminates ovarian metastases from adnexal tumors and other cutaneous metastases.

BACKGROUND

The distinction of metastatic ovarian carcinoma from other metastatic carcinomas and primary adnexal lesions in the skin is often difficult. PAX8 is a transcription factor that plays a critical role in development of the Müllerian system and has been shown to be a useful discriminatory marker between ovarian and breast carcinomas. Identification of ovarian cutaneous metastases may be of benefit in patients with familial breast-ovarian carcinoma syndrome.

METHODS

PAX8 immunohistochemical analysis was performed on 24 cases of metastatic adenocarcinomas to the skin and compared with 7 cases of primary adnexal lesions and also compared with p63 immunohistochemical staining results. Patients with metastatic adenocarcinomas had clinically documented primary malignancies, and patients with primary adnexal carcinomas had no known history of another adenocarcinoma.

RESULTS

Cutaneous ovarian and renal cell carcinoma metastases (2/2 and 8/8, respectively) showed positive nuclear expression of PAX8. PAX8 immunohistochemical staining in primary adnexal and other cutaneous metastases was completely negative (0/7 and 0/16, respectively). The p63 expression profile supported the distinction between adnexal and metastatic adenocarcinomas.

CONCLUSIONS

Although cutaneous ovarian metastasis is a rare phenomenon, the prognosis is extremely poor. PAX8 expression is a useful marker that effectively discriminated metastatic ovarian carcinomas from metastatic breast carcinomas and primary adnexal tumors.