Total Thyroidectomy is the treatment of choice for patients with MTC because of high incidence of multi-centricity, the more aggressive course and RAI therapy usually being not effective.
The central compartment nodes are frequently 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.
Similarly patient with tumors larger than 1 cm should undergo ipsilateral prophylactic modified radical neck dissection, because greater than 60% of these patients have nodal metastases. If ipsilateral nodes are positive, a contralateral node dissection should be performed.
In case of locally recurrent or metastatic disease, tumor debulking is advised, not only to ameliorate symptoms of flushing and diarrhoea, 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.
Chemotherapy is not effective.
If patients with MTC are found to have pheochromocytonta, this must be operated first.
Treatment of other thyroid malignancies is as follows :-
Papillary Thyroid Carcinoma (PCT)
High-risk tumors or bilateral tumors
- Total thyroidectomy (or near total thyroidectomy).
Low risk
- The treatment is controversial.
- Conservative approach advocates hemithyroidectomy (lobectomy+ isthmusectomy). More radical approach advocates total thyroidectomy (or near total thyroidectomy). - Schwartz Sx is in favour of radical approach.
(High and Low risk decided by any one of the many classification systems)
If enlarged lymph nodes are found
- Modified radical neck dissection is done of the affected side.
When patients are found to have a minimal papillary thyroid carcinoma in a thyroid specimen removed for other reasons,unilateral thyroid lobectomy and isthmusectomy is usually considered to be adequate treatment, unless the tumor has evidence of angio invasion, multifocality, or positive margins.
Follicular Thyroid Carcinoma (FTC)
FNA biopsy is unable to distinguish benign follicular lesions from follicular carcinomas therefore, preoperative diagnosis of cancer is difficult unless distant metastases are present.
Patients diagnosed by FNA biopsy as follicular lesions should undergo thyroid lobectomy + isthmusectomy (because at least 80% of these patients will have benign adenomas).
The resected lobe is subjected to histology (intraoperative frozen –section examination, though usually not helpful should be performed in high risk cases).