The Carcinoembryonic Antigen as a Potential Prognostic Marker for Neuroendocrine Carcinoma of the Breast

Aim: Primary neuroendocrine carcinomas of the breast (PNCB) are very rare and tumor markers for this indication are not well defined. We aim at reporting a case and providing a marker useful for prognosis and prediction of tumor recurrence for patients with PNCB. Case Report: A 75-year-old woman presented with a slight painful lump in her left breast of more than 6 months duration. Prior to surgery, the serum level of carcinoembryonic antigen (CEA) (54.4 ng/ml; normal limit <5.0 ng/ml) was significantly elevated. Ultrasonography identified a hypoechoic lesion. Mammography revealed a hyperdense lesion with a well-circumscribed margin. The patient underwent a modified radical mastectomy with axillary lymph node dissection. Pathology showed tumor cells with neuroendocrine features, with diffuse immunopositivity for chromogranin and synaptophysin. The tumor cells were also strongly positive for progesterone and estrogen receptor, but negative for HER-2/neu expression. The CEA value gradually decreased to the normal range within one month after surgery. Neither recurrence nor distant metastasis has been detected at 20 months after surgery and hormone therapy with letrozole. The serial CEA levels were within normal limits in the follow-up period. Conclusion: The serum CEA level after surgery may be a potential marker for evaluating tumor recurrence or prognosis of patients with PNCB.