Metastasis of primitive neuroectodermal tumor to the breast

We performed mammography and sonography on a 49-year-old woman who had a mass in her left axilla that had been present for 1 month and who had undergone excision of a primitive neuroectodermal tumor (PNET) on her back 1 year before. Mammography revealed 2 adjacent, dense nodules in the left breast and enlarged lymph nodes, without a fatty hilum or internal microcalcifications, in the left axilla. Sonography showed 2 round to oval, markedly hypoechoic nodules in the left breast and enlarged, markedly hypoechoic lymph nodes, without microcalcifications, in the left axilla. We then performed sonographically guided core biopsy. Histopathologic analysis of the specimens confirmed the presence of PNET in the left breast and axillary lymph nodes. The patient was then treated with chemotherapy. To our knowledge, this report is the first to describe radiologic findings of metastasis of PNET to the breast.