A 45-year-old white female presented a polypoid nodule in the vulva, one year after she was operated on for breast cancer. Histologic examination showed a poorly differentiated carcinoma that closely resembled the primary breast tumor. Eight similar cases have been previously described in the literature. This very rare event should be differentiated from primary adenocarcinoma of the mammary-like glands of the vulva. The recognition of such a lesion as primary or metastatic is very important, since it greatly influences management and prognosis.