Follicular thyroid carcinoma.

Follicular carcinomas are rare thyroid malignancies that are difficult to diagnose preoperatively. Fine needle aspiration is an excellent diagnostic tool and should be the initial step in managing the solitary thyroid nodule. Follicular carcinoma cannot be diagnosed with certainty by cytologic features alone; the diagnosis rests on the histologic findings of blood vessel or tumor capsule invasion. Surgical resection is the primary option for treatment. The extent of thyroidectomy for optimal survival outcome has not been determined scientifically. The outcome is excellent in minimally invasive follicular carcinoma with lobectomy and isthmusectomy; it is difficult to argue that total thyroidectomy is necessary. In a low risk prognostic group, for tumors other than minimally invasive carcinoma, lobectomy and isthmusectomy or total thyroidectomy can be justified. However, if total thyroidectomy can be done safely with a minimum of complications, then it has definite advantages for staging, postoperative surveillance, treatment, and possibly a lower recurrence rate and better survival rate. For all patients at high risk of recurrence, total thyroidectomy is preferred.