GATA3 staining in primary cutaneous apocrine cribriform carcinoma: Usefulness to differentiate it from breast cancer metastasis.

Background: Primary cutaneous apocrine cribriform carcinoma (PCACC) is a rare tumor, clinically appearing as a solitary nodule, mostly involving extremities of females and this lesion usually raises a differential diagnosis with metastatic cribriform carcinomas, especially breast cancer.

Objective: To study GATA3 expression in a series of 14 primary cutaneous cribriform carcinomas and to test its usefulness to differentiate this tumor from metastatic breast cancer.

Methods: We retrieved 14 cases with PCACC (each from a different patient) from the files of the authors. Cases were dated from 1994 to 2014. We also evaluated 6 cases of cutaneous breast cancer metastasis

Results: No PCACCs expressed GATA3. Breast cancer metastases expressed GATA3 in 100% of our studied cases.

Conclusions: Even though GATA3 expression has been reported in many benign and malignant adnexal tumors (mostly of sebaceous, follicular, and apocrine differentiation), as well as in many other neoplasms, GATA3 staining to differentiate PCACC from skin breast cancer metastasis has a high negative predictive value. A positive GATA3 staining in this context should permit one to rule out PCACC with a high level of confidence.