Role of Ultrasonography in Differential Diagnosis of Thyroid Nodules

PURPOSE: High-resolution ultrasound is a safe and costeffective method of identifying and characterizing thyroid nodules, and also for guiding aspiration cytology. But differentiating malignancy from the more frequently occurring benign thyroid nodules has proved challenging as there may be significant overlap in their sonographic appearance. The purpose of this study was to correlate the sonographic characteristics of thyroid nodules with the pathologic results after thyroidecotmy, and to establish the relative importance of these features for predicting the risk for malignancy. METHODS: We reviewed 516 thyroid nodules in 413 patients who underwent thyroidectomy between August 2003 and May 2005, after routine preoperative ultrasound. The following sonographic characteristics of the nodules were evaluated and we determined their sensitivity, specificity and positive predictive value: shape, margin, presence of halo, echo structure, internal echo, echogenicity, calcification and the type of vascularization. RESULTS: Of the 516 nodules, 327 were malignant nodules and 189 were benign nodules. The nodule size ranged from 5 to 80 mm at the greatest dimension (mean: 20.6 mm). The shape, margin, absence of halo, echo structure, and echogenecity showed statistically significant differences between the benign and malignant nodules in this study. Microcalcifications had low sensitivity but high specificity (13.1% vs 98.9%, respectively). Various combinations of features that have been suggested to be significant predictors of malignancy were also analyzed. The presence of all features was 100% specific for malignancy. According to the receiver operating characteristic curve, the best point for not over-looking malignancy is 2.5. At greater than this point, fine needle aspiration cytology is needed. CONCLUSION: This study has shown that ultrasonography is useful for differentiating between benign and malignant thyroid nodules and it can provide the proper indications for aspiration cytology.

Multimodal Therapeutic Approach in Anaplastic Thyroid Cancer / 대한내분비외과학회지

PURPOSE: Anaplastic thyroid cancer (ATC) is a rare but highly aggressive neoplasm with a dismal prognosis. However, a few patients survive for a long time after treatment. We tried to identify prognostic factors of this disease and analyzed treatment outcomes in patients with ATC. METHODS: We reviewed the medical records of 15 patients diagnosed with ATC in our institution between 1988 and 2003. The survival was compared by the Kaplan-Meier logrank test using SPSS program. RESULTS: The female-to-male ratio was 1.5:1 (9 women and 6 men), and the mean age at diagnosis was 63.9 years (range, 44~91). The mean tumor size was 6.3 cm (range, 4~10 cm). Extrathyroidal invasion was present in 12 cases and distant metastasis at diagnosis was present in 6 cases. Surgery was performed in 8 cases. Radiotherapy was used for 10 cases and chemotherapy for 5 cases. The mean overall survival time of the 15 patients was 237 days (range, 28~717 days). The 6~, 12~, 18~ and 24~ month survival rates were 33%, 26%, 13% and 0%. No association was found between survival and presenting symptoms, age, gender, tumor size, previous goiter history, extrathyroidal invasion, distant metastasis, surgery, radiotherapy or chemotherapy. A significantly better outcome was observed in patients received triple modality treatment (surgery, radiotherapy and chemotherapy) than in those received single or dual modality treatment (P=0.05). CONCLUSION: Although most patients with ATC had a poor prognosis, a multimodal approach including surgery, radiotherapy and chemotherapy, might improve survival.

Risk Factors and Prognosis of Recurrent Thyroid Cancer / 대한내분비외과학회지

PURPOSE: Differentiated thyroid cancer is known to be one of cancers which have a favorable prognosis and long-term survival resulting from slow growth of tumor and late distant metastasis. Patients are nearly cured of thyroid cancer after first operation. But, some of those have high risk factors of recurrence. Practically it has been reported that 20% of those have recurrence of cancer and 50~60% of patients died of recurrence. We analyzed factors involving to recurrence after initial treatment, frequency and site of recurrence, disease-free interval, and results of treatment. Based on this information, we investigated therapeutics to decrease the rate of recurrence and prognostic factors to expect death. METHODS: 1803 patients were primarily operated for thyroid cancer in Kyungpook National University Hospital between 1985 and 2003. Among the cases, we reviewed the clinical records of 124 patients (6.9%) who had recurrent thyroid cancer. We analyzed the difference in frequency of recurrence on the basis of sex, age, histologic types, risk groups, and lymph node metastases when they had a first operation. The correlation between these factors and mortality rate was analyzed statistically by using Chi-square test and Fisher's exact probability test. RESULTS: Post-operative recurrence of thyroid cancer was highly observed in over 40 years old at first operation (8.4% vs. 4.9%), men (17.1% vs. 3.9%). Similarly, in the case of medullary or poorly-differentiated thyroid cancers, the groups of patients with high-risk (12.3% vs. 3.9%) or with lymph node metastases (13.5% vs. 3.7%) have high frequency of recurrence. Among the 124 patients, 53.3% cases have regional recurrence sites and 20.1% have local, 17.7% distant metastases, and 1.6% combined locoregional. The number of patients who died of recurrent cancer was 32 of 124 cases. Major cause of the death was distant metastases. In the case of 104 patients who had recurrent differentiated thyroid cancer, significant prognostic indicators of low survival rates are age greater than 45 years, neck dissection at second operation and distant metastases. CONCLUSION: In order to decrease the rate of local and regional recurrence in thyroid cancer, we conclude that complete resections of thyroid tissue and cervical lymph nodes have to be operated specially in the group with high-risk. Although adjacent organs are infiltrated, active treatment should be carried out. The treatment of most medullary or poorly-differentiated thyroid cancers which result in the death of distant metastases still remains to be studied.