[Histopathological study of juvenile thyroid carcinoma].

We have examined 12 cases of juvenile thyroid carcinoma histopathologically. The characteristics uncovered of juvenile thyroid carcinoma have been summarized below. 1) The predominant histological type was a papillary carcinoma with abundant follicular components. Which was inclined to show trabecular and solid pattern. 2) The growth pattern was highly infiltrative, showing a frequent extrathyroidal extension, a wide intrathyroid spread, and a severe involvement of the lymph nodes. 3) Many psammoma bodies were observed frequently. 4) Remarkable lymphocytic infiltration was seen in the thyroid around the tumor, and in one case it resembled chronic thyroiditis. In addition, a case of a multicentric papillary carcinoma showed unusual histological features.