To the Editor.—The panel, "Carcinoma of the Thyroid" (Arch Surg 110:783-789, 1975), was interesting and stimulating. But I should like to add an important diagnostic tool not mentioned by the members of the panel. In decision-making for choice of strategy and treatment, I have found it very useful to take a fine-needle aspiration biopsy specimen from the thyroid. The biopsy is performed after the scintigraphy, which is used as guidance in localizing non-active thyroid tissue. With fine-needle biopsy we can identify differentiated thyroid carcinoma and thyroid adenoma. We also can get support for our clinical diagnosis of nodular nontoxic colloid goiter and often can verify the diagnosis of chronic thyroiditis. Our surgical tactics according to the thyroid gland are as follows: thyroid carcinoma (papillary, follicular, medullary), total thyroidectomy; anaplastic carcinoma and sarcoma, cytology makes it possible to start radiotherapy immediately; thyroid adenoma (microfollicular, oxyphilic, embryonal, trabecular), hemithyroidectomy; nodular nontoxic