<s>[INST] context: Pheochromocytoma must be operated on first.
These tumors are generally (>50%) bilateral. Total thyroidectomy is the treatment of choice for patients with MTC because of the high incidence of multicentricity, the more aggressive course, and the fact that 131I therapy usually is not effective.
Central compartment nodes frequently are involved early in the disease process, so that a bilateral central neck node dissection should be routinely performed.
In patients with palpable cervical nodes or involved central neck nodes, ipsilateral or bilateral, modified radical neck dissection is recommended.
The role of prophylactic lateral neck dissection is controversial.
However, in patients with tumors >1 cm, ipsilateral prophylactic modified radical neck dissection is recommended because >60% of these patients have nodal metastases.
If ipsilateral nodes are positive, a contralateral node dissection should be performed.
In the case of locally recurrent or metastatic disease, tumor debulking is advised not only to ameliorate symptoms of flushing and diarrhea, but also to decrease risk of death from recurrent central neck or mediastinal disease.
External beam radiotherapy is controversial, but is recommended for patients with unresectable residual or recurrent tumor.
There is no effective chemotherapy regimen.
Radiofrequency ablation done laparoscopically appears promising in the palliative treatment of liver metastases >1.5 cm.
In patients who have hypercalcemia at the time of thyroidectomy, only obviously enlarged parathyroid glands should be removed.
The other parathyroid glands should be preserved and marked in patients with normocalcemia, as only about 20% of patients with MEN2A develop HPT.
When a normal parathyroid cannot be maintained on a vascular pedicle, it should be removed, biopsied to confirm that it is a parathyroid, and then autotransplanted to the forearm of the nondominant arm.
Total thyroidectomy is indicated in RET mutation carriers once the mutation is confirmed.
The procedure should be performed before age of 5 years in MEN2A patients and before age 1 year old in MEN2B patients.
Central neck dissection can be avoided in children who are RET -positive and calcitonin-negative with a normal ultrasound examination.
When the calcitonin is increased or the ultrasound suggests a thyroid cancer, a prophylactic central neck dissection is indicated. [/INST] question: Treatment of Medullary Carcinoma thyroid: | options: A: Surgery and Radiotheryapy B: Radiotherapy and Chemotherapy C: Surgery only D: Radioiodine ablation | answer: C </s>