Abstract
Fifteen cases diagnosed as follicular carcinoma of the thyroid at the department in a past 14-year period were reevaluated, and it was found that eleven cases out of them satisfied the diagnosis criteria for follicular carcinoma. Except for 2 cases associated with papillary carcinoma, follicular carcinoma of the thyroid represented 6.4% (9/141 cases) of all malignant tumors of the thyroid. In this study nine cases were clinicopathologically studied. Their ages ranged from 32 to 72 years old, with a mean of 52.1. There were one man and 8 women. Their clinical courses were observed during one years and 5 months to 11 years. In the same period distant metastasis was noted in only 2 cases which already had bone metastasis at the first visit to the hospital. Operative procedures included total thyroidectomy or subtotal thyroidectomy with modified neck dissection in 5 cases, lobectomy with lymph node dissection (I_??_IV) in one case, and lobectomy in one case. For the bone metastasis in the 2 cases excision of the 6th thoracic vertebral body or removal of the right pelvis was performed in each case, respectively. Bone metastasis cases had a tumor with diameter of 5.2cm in average versus 2.8cm in non-metastasis cases. Histopathologically vascular invasion was observed in 44.4%i (4/9 cases) and capsular invasion in 88.9% (8/9). All cases with metastatic lesion revealed significant vascular invasion and invasion into the thick capsule. There was no significant difference in histologic differentiation (well or poorly differentiated type) between patients groups with and without metastasis.
