The recent prevalence of ultrasound-guided fine-needle aspiration biopsy has resulted in a marked increase in the number of patients with papillary microcarcinoma (maximum diameter,

We describe an accurate and simple method of diagnosing thyroid nodules by the modified technique of ultrasound-guided fine needle aspiration biopsy (UG-FNAB). An Aloka SSD 2000 focus type scanner (Aloka Co., Tokyo, Japan) equipped with a 10-MHz mechanical sector probe and a 7.5-MHz convex probe was used. First, a clear picture of the thyroid gland was taken with the use of the 10-MHz probe to determine the abnormalities. Then, a 7.5-MHz probe (1.5 x 0.8 cm of surface area) was used to guide the needle perpendicularly to the neck. This method enabled us to obtain samples from nodules greater than 5 mm. We applied this technique to 1000 patients who had uncertain diagnosis by the conventional method of FNAB. The advantages of this method are as follows: (i) The use of a small probe (7.5 MHz) is most important, since a needle can be inserted by watching the monitor without an assistant. (ii) The biopsy site can be chosen precisely. (iii) Small thyroid cancers, i.e., 5 mm cancer, can be biopsied without any difficulty. (iv) A life-threatening anaplastic carcinoma can be diagnosed at an early stage. (v) An intraglandular metastasis to the opposite lobe can be detected. (vi) Cystic carcinoma, difficult to diagnose by FNAB, can be diagnosed accurately. This method is highly recommended for all clinicians who are currently doing FNAB.

The fate of benign thyroid nodules has been unknown because there has been no study in this regard. We re-examined 134 patients with thyroid nodules who had had benign aspiration biopsy cytology 9 to 11 years ago. The thyroid gland was palpated by the same two thyroidologists throughout the study. Ultrasonography, fine-needle aspiration biopsy (FNAB), and ultrasound-guided FNAB were employed to examine the nature of nodules of 9 to 11 years' duration. Patients (n = 61) who had nodules difficult to palpate (small nodules), multiple nodules, or cystic nodules with papillomatous proliferation underwent ultrasound-guided FNAB; patients (n = 55) having a distinctly palpable single nodule underwent usual FNAB. None of the patients received any medical or surgical treatment. There were 86 single nodules, 14 multiple nodules, and 34 cystic nodules on the first examination. These benign nodules were reexamined for changes in size and cytology 9 to 11 years later. The most striking finding was a decrease in size or disappearance of the nodule in 42% to 79% of benign nodules. About 92% of nodules remained benign without changing cytologic classification. Only one case (0.9%) previously regarded as benign turned out to be malignant; this nodule grew in size compared with the previous examination. Among single and multiple nodules, 21% to 23% of the nodules increased in size; however, most patients with enlarged nodules (86%) showed the same class 2 cytology as before. Our present study indicates that biopsy-proved benign thyroid nodules remain benign over a prolonged period. Thus no medical or surgical treatment is required so long as the nodules do not grow.

Multiple endocrine neoplasia (MEN) type 2B is a clinically distinct entity among the autosomal dominant MEN 2 syndromes. Most patients with MEN 2B carry a germline mutation (M918T) of the RET proto‐oncogene, while a few carry A883F. We examined a patient with MEN 2B, but without M918T or A883F, and her relatives. Here, we report the presence in this patient of 2 germline mutations, V804M and Y806C in the same allele. While the novel Y806C was inherited from her father, its carriers (her father and brother) was not affected by MEN 2. In contrast, V804M was a de novo mutation, that has been reported in patients with familial medullary thyroid carcinoma. Combinations of mutations of the RET proto‐oncogene may cause oncogenic activities different from those of single mutations.

Ultrasonography is the most useful tool for detection and evaluation of thyroid nodules. In this study, we present our classification system for ultrasonographic evaluation, which has been routinely performed since 1995. Of 1244 nodules identified by ultrasonography in 900 patients, 1145 nodules demonstrating adequate specimens on fine-needle aspiration biopsy were enrolled in the study. We stratified these nodules into classes 1 to 5 with intermediate steps of 0.5 for classes 2 to 5. Nodules classified as 3.5 or greater were evaluated as malignant, those classified as 3 were evaluated as borderline, and those classified as 2.5 or lower were evaluated as benign. Of 233 nodules evaluated as malignant, 179 (76.8%) were cytologically confirmed as malignant. Furthermore, 145 of 159 nodules (91.2%) classified as 4 or greater were cytologically diagnosed as carcinoma. Of 710 nodules evaluated as benign, 683 (96.1%) were cytologically confirmed as benign. Two hundred fifty-five nodules of 210 patients were surgically resected and pathologically examined. In this series, the positive predictive value of ultrasonographic evaluation of malignancy was 97.2%. These findings suggest that our classification system is simple and useful to facilitate ultrasonographic evaluation of thyroid nodules.