RESUMEN
OBJECTIVE@#To raise clinical awareness of carcinoembryonic antigen(CEA) increased as initial manifestation of medullary thyroid cancer(MTC) and explore the diagnosis and treatment.@*METHOD@#Clinical data of 2 cases CEA increased as the initial presentation of MTC were retrospectively analyzed and clinical manifestations of the disease, diagnosis, treatment were also discussed by literature reviewing.@*RESULT@#Two patients received thyroid ipsilateral lobe total resection, MTC was confirmed by intraoperative frozen pathology, re-total resection of the contralateral lobe and bilateral VI lymph node dissection were performed. Lymph nodes had no metastasis confirmed by pathological frozen examination. CEA returned to normal within 2 months after surgery. No tumor recurrence and metastasis were found after follow-up for 3 to 24 months.@*CONCLUSION@#CEA increased as the initial presentation MTC was rare and clinical identification of CEA increased disease should be taken into account the MTC as possible. Total thyroidectomy and bilateral VI lymph node dissection was the main surgical treatment for it.