Treatment of medullary thyroid carcinoma with apatinib: A case report and literature review

RATIONALE: Medullary thyroid carcinoma (MTC) is a rare type thyroid carcinoma originating from the thyroid parafollicular cells (C cells). Chemotherapy has a limited efficacy for treating persistent or recurrent MTC. PATIENT CONCERNS: A 46-year-old woman who underwent thyroidectomy for MTC in December 2007. She began experience recurring diarrhea in January 2015 and started to cough and feel shortness of breath in March 2016. DIAGNOSES: A chestcomputed tomography (CT) scan showed metastases in the bilateral lungs, pulmonary hilum, and mediastinal lymph nodes. Percutaneous biopsy of the pulmonary occupying lesions performed on March 21, 2016 indicated medullary carcinoma metastases at the right pulmonary hilum. INTERVENTIONS: This patient was treated with oral apatinib (500 mg daily). OUTCOMES: The patient's symptoms of diarrhea, coughing, and shortness of breath disappeared. CT reexaminations for efficacy assessment at 1, 2, and 3 months after the treatment indicated partial remission. Systemic migrating bone and joint pains occurred during the treatment, which were considered to be adverse events of apatinib. LESSONS: Treatment of MTC with apatinib has been shown to be effective in our case. Tyrosine kinase inhibitors (TKIs) that suppress rearranged during transfection (RET) and vascular endothelial growth factor receptor (VEGFR) should be considered as a effective therapeutic approaches.