Pathologic basis of the sonographic differences between thyroid cancer and noninvasive follicular thyroid neoplasm with papillary-like nuclear features

Ultrasonography is pivotal in triage thyroid biopsy in the era after the identification of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). This pictorial essay illustrates the pathologic basis of the sonographic features that distinguish NIFTP from thyroid cancers. In this study, we present the correlations of ultrasonography to ×1 histopathology to assess shape and margin characteristics. Markedly hypoechoic nodules correlate to microfollicular/solid nodules, while isoechoic/hyperechoic thyroid nodules correlate to normofollicular/macrofollicular nodules. The ultrasound findings of NIFTP and minimally invasive encapsulated thyroid cancers are similar. Both are well-circumscribed, oval-to-round nodules with regular margins. Blurred or microlobulated margins indicate infiltrating tumors, while lobulated margins are characteristic of expansile tumors. Overtly invasive encapsulated tumors are characterized by oval-to-round nodules with irregular or lobulated margins. The ultrasound findings for infiltrative thyroid cancers show at least one of the following malignant features: marked hypoechoicity, taller-than-wide shape, microcalcifications, and blurred or microlobulated margins.

Thyroid Ultrasound: Change of Inter-observer Variability and Diagnostic Performance after Training

PURPOSE: To investigate and compare inter-observer variability and diagnostic performance of thyroid ultrasound (US) between a faculty member and observing residents. MATERIALS AND METHODS: From October 2007 to June 2009, 18 residents underwent training in thyroid US section. Group 1 included 8 residents that were trained for the first time and group 2 included 10 residents that were trained for the second time. US features of nodules were recoded according to the composition, echogenicity, margin, calcifications, shape, and final assessment by a faculty member and residents, respectively. Following a discussion, a faculty member performed fine needle aspiration. Then, the inter-observer variability and diagnostic performance between a faculty member and residents were investigated and compared for US. RESULTS: In group 1, agreement for composition in resident 1, calcification for residents 5 and 6, and shape for resident 4 were slight, moderate, moderate, and moderate, respectively. In group 2, agreement for composition in residents 1 and 10 were moderate. Substantial or greater agreement was observed more frequently in group 2 than 1. The diagnostic performances for both the faculty and residents were high and not statistically different. CONCLUSION: Agreement for US features between a faculty and residents as well as diagnostic performance were high. Moreover, diagnostic performance of residents that underwent training a second time of training was higher than residents that underwent training only once.

Ultrasound-Guided Fine-Needle Aspiration Biopsy in Infracentimetric Thyroid Nodules

PURPOSE: The aim of this study is to determine the efficacy of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) of thyroid nodules that are equal to or less than 1 cm at the maximum diameter. MATERIALS AND METHODS: The US-FNABs performed on thyroid nodules from March to August 2009 were included in this study. We retrospectively evaluated the cytopathologic results as well as any complications associated with the procedure. RESULTS: Of the 241 thyroid nodules (range: 0.1 - 1.0 cm, mean size: 5.8 mm) in 184 patients (female: male = 164:20, mean age: 49.0 years, age range: 18 - 77 years old), the incidence of an inadequate sample was 14.1% (34/241) for the US-FNABs. Eighty six nodules were surgically removed in 62 patients, of which 15 were confirmed to be benign nodules and 71 were confirmed to be malignant nodules. The number of true positive, false positive, true negative and false negative results for US-FNAB were 59, 0, 10 and 3%, respectively, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 95.2%, 100%, 100%, 76.9% and 95.8%, respectively. All the false negative cases were less than 3 mm at the maximal diameter. There were no serious complications in all the patients. CONCLUSION: US-FNAB was effective for the cases of thyroid nodule under 1 cm at the maximal diameter. However, a false negative result of US-FNAB should be considered for the cases of very small nodules that are less than 3 mm at the maximal diameter.

Sporadic medullary thyroid carcinoma: clinical data from a university hospital

INTRODUCTION: Medullary thyroid carcinoma may occur in a sporadic (s-medullary thyroid carcinoma, 75 percent) or in a multiple endocrine neoplasia type 2 form (MEN2, 25 percent). These clinical forms differ in many ways, as s-medullary thyroid carcinoma cases are RET-negative in the germline and are typically diagnosed later than medullary thyroid carcinoma in MEN2 patients. In this study, a set of cases with s-medullary thyroid carcinoma are documented and explored. PURPOSE: To document the phenotypes observed in s-medullary thyroid carcinoma cases from a university group and to attempt to improve earlier diagnosis of s-medullary thyroid carcinoma. Some procedures for diagnostics are also recommended. METHOD: Patients (n=26) with apparent s-medullary thyroid carcinoma were studied. Their clinical data were reviewed and peripheral blood was collected and screened for RET germline mutations. RESULTS: The average age at diagnosis was 43.9 years (± 10.82 SD) and did not differ between males and females. Calcitonin levels were increased in all cases. Three patients presented values that were 100-fold greater than the normal upper limit. Most (61.54 percent) had values that were 20-fold below this limit. Carcinoembryonic antigen levels were high in 70.6 percent of cases. There was no significant association between age at diagnosis, basal calcitonin levels or time of disease onset with thyroid tumor size (0.6-15 cm). Routine thyroid cytology yielded disappointing diagnostic accuracy (46.7 percent) in this set of cases. After total thyroidectomy associated with extensive cervical lymph node resection, calcitonin values remained lower than 5 pg/mL for at least 12 months in eight of the cases (30.8 percent). Immunocyto- and histochemistry for calcitonin were positive in all analyzed cases. None of the 26 cases presented germline mutations in the classical hotspots of the RET proto-oncogene. CONCLUSION: Our cases were identified late. The basal ...

Ultrasound-guided Fine-needle Aspiration Biopsy of Thyroid Nodules: Comparison of the Pain Scale according to the Application of Local Anesthesia

PURPOSE: This study was designed to evaluate the difference in the degree of patient pain during an ultrasoundguided fine-needle aspiration biopsy (US-FNAB) with the use of a one-needle puncture for thyroid nodules with the application of local anesthesia. MATERIALS AND METHODS: We prospectively examined patients who simultaneously received US-FNAB for two thyroid nodules, for one nodule in the right lobe and one nodule in the left lobe, where the nodules were larger than 10 mm in the maximum diameter. US-FNAB with or without local anesthesia was performed with the use of a 23-guage needle in all patients. The degree of pain after performing US-FNAB was evaluated by the use of an 11-point numeric rating scale. RESULTS: For all 20 patients, US-FNAB was performed with an alternative selection of the nodules. There were 14 patients with a higher pain score where local anesthesia was administered, two patients with a higher pain score where local anesthesia was not administered and four patients with the same score where both methods were used. There was a statistically significant difference in the pain score between the use of the two methods (Wilcoxon sign rank test, p = 0.014). The mean value of the pain score was 3.1 in patients who received local anesthesia and 2.1 in patients that did not receive local anesthesia, respectively. CONCLUSION: The use of local anesthesia is not superior to the use of no anesthesia regarding pain relief if USFNAB is performed with a one-needle puncture.

The Utility of US-Guided Core-Needle Biopsy in the Diagnosis of Thyroid Nodules

Ultrasonography (US)-guided fine needle aspiration biopsy (FNAB) is widely considered to be the diagnostic technique of choice in the assessment of nodular disease of the thyroid gland. Although the accuracy of FNAB analysis approaches 95% where there is an adequate sample, non-diagnostic sampling occurs in 10-20% of cases. Additionally, equivocal pathological results are obtained in 10-30% of cases, and there are limitations in detecting subtypes of certain diseases, such as lymphoma. Generally, US-guided core needle biopsy (CNB) allows for the procurement of a large, grossly visible specimen and a more precise pathological diagnosis. Therefore, US-guided CNB is indicated in the following situations: 1) when an inadequate specimen is obtained by FNAB, 2) when FNAB yields indeterminate or inadequate information, 3) when targeting of the lesion is difficult because it is diffuse, and 4) when there is a discrepancy between the imaging findings and the FNAB results. In this article, we describe the situations in which US-guided CNB is useful for diagnosing thyroid lesions.

Ultrasound-Guided Fine-Needle Aspiration Biopsy of Multiple Thyroid Nodules

PURPOSE: To standardize the number of nodules which necessitates ultrasound-guided, fine-needle, aspiration biopsy in patients who have multiple thyroid nodules with the same sonographic characteristics as each other. MATERIALS and METHODS: From February, 2002 to March, 2004, among patients whose diagnosis was confirmed by ultrasound-guided, fine-needle, aspiration biopsy, 545 nodules of 203 patients were found in sonography with more than two thyroid nodules. Each thyroid gland nodule was classified on a score from 0 to 2 points on the basis of the following 5 characteristics: internal content, margin, echogenicity, shape and calcification in sonography. When the score of all characteristics was the same, by deciding on nodules with the same sonographic char-acteristics and with the score of at least one characteristic being different, we divided the nodules with different sonographic characteristics in a patient. By methods such as given in the preceding descriptions, patients with multiple thyroid nodules were separated into two groups: one in which all nodules had the same sonographic characteristics and another in which nodules have at least one different sonographic characteristic. Then, each pathologic result was searched for the same case and different case in each patient group. RESULTS: Among the 203 patients who were diagnosed with multiple thyroid nodules in ultrasonography, 79 patients (38.9%) had nodules with the same ultrasonographic characteristics and 124 patients (61.1%) had nodules with at least one different ultrasonographic characteristic. All 79 patients' nodules with the same ultrasono-graphic characteristics in each patient showed the same pathologic result in all cases (100.0%) and there was no case showing a different pathologic result. Otherwise, among the 124 patients' nodules with different ultrasono-graphic characteristics, each patient showed the same pathologic result in 111 (89.5%) and different pathologic result in 13 (10.5%). CONCLUSION: In patients who have multiple thyroid nodules, if a patient's nodules have the same sonographic characteristics, we can perform ultrasound-guided, fine-needle, aspiration biopsy about only one nodule and if a patient's nodules have different sonographic characteristics from each other, we must perform the biopsy for all nodules.

US Guided Fine-needle Non-suction Technique: A Useful and Comfortable Method for Thyroid Nodule

as useful as the conventional suction technique for the cytopathological evaluation of thyroid nodules.

Analysis of the Factor which Affect to Acquisiton Rate of Ultrasound-Guided Fine Needle Aspiration of Thyroid Nodules

PURPOSE: The purpose of this study is to evaluate the acquisition rate of adequate specimens in the ultrasoundguided percutaneous needle aspiration biopsy (US-PCNB) of thyroid nodules and to find the factors influencing the acquisition rate. MATERIALS AND METHODS: We conducted a prospective study in 132 patients who had a total of 215 nodules. Aspiration biopsy was performed with 21-gauge fine needles for 111 nodules (62 patients) and with 20-gauge cutting needles for 104 nodules (70 patients). We calculated the overall acquisition rate of adequate specimens of US-PCNB and compared the acquisition rates according to the kind of needle, and the size, nature and palpability of the nodules. RESULTS: The total acquisition rate of adequate specimens was 87.4%. There was no difference in the acquisition rate between the 20-gauge cutting needle and the 21-gauge needle. The acquisition rate of the solid nodules (90.2%) was higher than that of the cystic nodules (78.8%). However, the size and palpability of the nodules did not significantly affect the acquisition rate of the specimens. CONCLUSION: The acquisition rate of adequate specimens in the US-PCNB of thyroid nodules was high. The acquisition rate of the solid nodules was higher than that of the cystic nodules. However, there was no statistically significant difference in the acquisition rate according to the kind of needle, or the size and palpability of the nodules.

Ultrasound-Guided Fine Needle Aspirations of Thyroid Nodules: Assessment of Nondiagnostic Samples

PURPOSE: To determine the frequency of malignancy among the nondiagnostic specimens by ultrasound-guided, fine needle aspiration (US-FNA) and to analyze the factors which cause the nondiagnostic specimens of thyroid nodules. MATERIALS AND METHODS: Data were collected from 425 patients (58 male, 367 female) who underwent US-FNA of the thyroid nodule between February, 2002 and October, 2003. The study included 784 nodules from 425 patients. US-FNA was performed 1 to 3 times by two radiologists using a 10MHz linear probe and a 21-gauge fine needle. The percentage of total nondiagnostic specimens was obtained and the percentage of nondiagnostic specimens according to the thyroid nodule's size and nature was analyzed. Thyroid nodules were classified according to their sizes and natures. The nodules were divided by size as either 1cm or more, or less than 1cm in diameter. Each nodule was classified as cystic (pure cystic), mixed (solid portion of nodule2/3). The percentage of malignancy among nondiagnostic specimens was determined and compared to the malignancy rate among diagnostic specimens. Chi-square test and Fisher's exact test were used for statistical significance. RESULTS: Among the 784 nodules, 95 (12.1%) were nondiagnostic. The percentage of nondiagnostic specimens increased as the cystic content increased (p<0.0001). The malignancy rate of the diagnostic specimens was higher than that of the nondiagnostic specimens, but the difference was not significant. CONCLUSION: The cystic content of each nodule was the only significant predictor of nondiagnostic specimens. There was no significant difference in malignancy rate between nondiagnostic and diagnostic specimens. It is suggested that when evaluating an initially nondiagnostic US-FNA, repetitive US-FNA or follow-up USG should be performed.

Ultrasound-Guided Fine-Needle Aspiration Biopsy in Nonpalpable Thyroid Nodules: Is It Useful in Infracentimetric Nodules?

The purpose of this study was to evaluate the usefulness of an ultrasound-guided fine-needle aspiration biopsy (US-FNAB) for the evaluation and treatment planning of nonpalpable thyroid lesions, including infracentimetric nodules. One hundred and twenty one patients underwent US-FNAB for 149 non-palpable solid nodules. Sixty-five patients underwent surgery, and 84 were followed up for at least 36 months. The results of the US-FNAB correlated with the pathological findings and clinical follow-up results. The nodules ranged from 0.3 to 2 cm in diameter, with a mean of 0.8cm. Among the 149 nodules, 115 were infracentimetric and 34 were centimetric or supracentimetric in size. Of the 149 thyroid nodules, US-FNAB was true positive in 43, true negative in 90, false positive in 7 and false negative in 1. In 8 cases, the lesion was inadequately sampled. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the US-FNAB for the infracentimetric nodules were 96.9, 93.4, 86.1, 98.6 and 94.4%, and for the centimetric or supracentimetric nodules, were 100, 90.5, 85.7, 100 and 93.9%, respectively. There were no significant differences in the results between the infracentimetric and centimetric or supracentimetric nodules. In conclusion, an US-FNAB is a useful tool for determining the treatment plan of non-palpable solid thyroid nodules, even when less than 1 cm in diameter, and shows high sensitivity, specificity and accuracy.

Incidentally Found Thyroid Nodules in Women with no Previous Thyroid Disease: Its Significance

PURPOSE: To determine the prevalence of thyroid nodules discovered incidentally at ultrasonography and to reassess their significance. MATERIALS AND METHODS: During a six-month period and using a high-frequency transducer, 1033 subjects with suspected breast disease underwent a prospective study of the thyroid. We determined the prevalence of thyroid nodules according to age, and the malignancy rate. RESULTS: Focal thyroid nodules were detected in 291 women (28.2%), their prevalence increasing with age (p<0.01). The nodules, totalling 337, were single in 260 cases (89.3%) and multiple in 31 (10.7%); 271 were less than 1 cm in diameter, 53 were 1-2 cm, and 13 were more than 2 cm [mean, 7.1(range, 2-34) mm]; 126 (37.4%) were pure cysts, 62 (18.4%) were mixed, and 149 (44.2%) were solid. Of the 149 solid nodules, 139 were hypoechoic. Eighty women (with 106 nodules) underwent fine-needle aspiration bipsy, and 35 (with 45 nodules) underwent surgery. It was discovered, finally, that 29 women (2.8%) had 35 malignancies, of which 33 were papillary carcinomas and two were carcinomas which had metastasized from a breast malignancy. Eleven women (37.9%) had extrathyroidal invasion and 6 (20.7%) had cervical lymph node metastasis despite incidentaloma. CONCLUSION: The prevalence of incidentally found thyroid nodules was 28.2%. Since the malignancy rate of these was relatively high, at 10.4%, the clinical significance of this finding should be reassessed.