The Changes in the Trend of Thyroid Cancer incidence for Korean Population: Consecutive 10 Years Analysis (2004-2013) / 대한두경부종양학회지

Background/Objectives@#To analyze changes in the incidence of thyroid cancer for Korean population using big data from the National Health Insurance Service.Materials & Methods: Sample cohort database between January 2004 and December 2013 with 1,000,000 cases for each year was enrolled in this study. Thyroid cancer incidence was analyzed by sex, age and by region. Public health insurance payment was used to reflect socioeconomic status. @*Results@#The incidence of thyroid cancer in Korea increased for 10 years annually. There are 3 times increasing in the incidence rate of thyroid cancer from 2004, 0.03% to 2013, 0.09%. The sex ratio in the incidence rate of thyroid cancer was male : female = 1:7.2 in 2004 and male : female = 1:3.6 in 2013 that suggest decreased gap between the sex ratio. Between 2004 and 2010, the incidence rates of those in their 40s were found to be the highest, whereas the incidence rates for those in their 50s were found to be highest from 2011 and thereafter. Every year the high socioeconomic status group showed a higher incidence of thyroid cancer than low socioeconomic status group. Some specific region showed continuous high incidence of thyroid cancer, not all city and state. @*Conclusion@#The incidence rate of thyroid cancer for 10 years had special feature by sex, age, socioeconomic status and especially by region. This results will be a barometer for further epidemiologic study about the incidence of thyroid cancer for Korean population

The Changes in the Trend of Thyroid Cancer incidence for Korean Population: Consecutive 10 Years Analysis (2004-2013) / 대한두경부종양학회지

Background/Objectives@#To analyze changes in the incidence of thyroid cancer for Korean population using big data from the National Health Insurance Service.Materials & Methods: Sample cohort database between January 2004 and December 2013 with 1,000,000 cases for each year was enrolled in this study. Thyroid cancer incidence was analyzed by sex, age and by region. Public health insurance payment was used to reflect socioeconomic status. @*Results@#The incidence of thyroid cancer in Korea increased for 10 years annually. There are 3 times increasing in the incidence rate of thyroid cancer from 2004, 0.03% to 2013, 0.09%. The sex ratio in the incidence rate of thyroid cancer was male : female = 1:7.2 in 2004 and male : female = 1:3.6 in 2013 that suggest decreased gap between the sex ratio. Between 2004 and 2010, the incidence rates of those in their 40s were found to be the highest, whereas the incidence rates for those in their 50s were found to be highest from 2011 and thereafter. Every year the high socioeconomic status group showed a higher incidence of thyroid cancer than low socioeconomic status group. Some specific region showed continuous high incidence of thyroid cancer, not all city and state. @*Conclusion@#The incidence rate of thyroid cancer for 10 years had special feature by sex, age, socioeconomic status and especially by region. This results will be a barometer for further epidemiologic study about the incidence of thyroid cancer for Korean population

Surgical Treatment Guidelines for Patients with Differentiated Thyroid Cancer: The Korean Association of Thyroid and Endocrine Surgeons (KATES) Guidelines Taskforce / 대한내분비외과학회지

No abstract available.

Effect of a Low Iodine Diet vs. Restricted Iodine Diet on Postsurgical Preparation for Radioiodine Ablation Therapy in Thyroid Carcinoma Patients

PURPOSE: The radioiodine ablation therapy is required for patients who underwent a total thyroidectomy. Through a comparative review of a low iodine diet (LID) and a restricted iodine diet (RID), the study aims to suggest guidelines that are suitable for the conditions of Korea. MATERIALS AND METHODS: The study was conducted with 101 patients. With 24-hour urine samples from the patients after a 2-week restricted diet and after a 4-week restricted diet, the amount of iodine in the urine was estimated. The consumed radioiodine amounts for 2 hours and 24 hours were calculated. RESULTS: This study was conducted with 47 LID patients and 54 RID patients. The amounts of iodine in urine, the 2-week case and 4-week case for each group showed no significant differences. The amounts of iodine in urine between the two groups were both included in the range of the criteria for radioiodine ablation therapy. Also, 2 hours and 24 hours radioiodine consumption measured after 4-week restrictive diet did not show statistical differences between two groups. CONCLUSION: A 2-week RID can be considered as a type of radioiodine ablation therapy after patients undergo a total thyroidectomy.

The prophylactic effects of gabapentin on postoperative sore throat after thyroid surgery / 대한마취과학회지

BACKGROUND: Postoperative sore throat (POST) is considered a usual complication after tracheal intubation, especially, thyroid surgery. Gabapentin is a widely studied multimodal perioperative drug, which can be used to treat acute postoperative pain. The primary endpoints of this study was a reduction of the incidence of POST at rest and during the swallowing movements after thyroid surgery. And the second endpoints was a reduction of the intensity of the POST after thyroid surgery. METHODS: Seventy-one patients that underwent elective thyroid surgery received either gabapentin (Neurontin(TM) 600 mg) or placebo, orally, one hour before anesthesia. The VAS scores and incidences of POST and adverse effects were determined at 1 hr, 6 hr, 12 hr, and 24 hr after surgery at rest and during swallowing movement. RESULTS: The gabapentin group (N = 36) showed a lower incidence of POST than the placebo group (N = 35) (47% vs. 78%, P = 0.038), and had significant lower VAS score at 6 and 24 hours after surgery in the resting state. However, during the movement, no intergroup differences were found in terms of the incidence of POST (83% vs. 91%, P = 0.305) or VAS score. Furthermore, no significant difference was observed between the two groups, in adverse effects. CONCLUSIONS: Gabapentin (Neurontin(TM) 600 mg) administered 1 hr before anesthesia reduced the intensity and incidence of POST during the resting state without a significant adverse event, during the 24 hr after thyroid surgery. However, gabapentin did not reduce the intensity and incidence of POST during the swallowing movement.

Follicular Variant of Papillary Thyroid Carcinoma: Clinical Features and Surgical Strategy

PURPOSE: The follicular variant of papillary thyroid carcinoma (FVPTC) is difficult to diagnose and there is continuous debate regarding the optimal extent of surgery. METHODS: One hundred sixty three patients (17 male, 146 female; mean age 43.3 years), who underwent a thyroidectomy with a final diagnosis of FVPTC were divided into the total thyroidectomy group (Group I, n=74) and the less- than total thyroidectomy group (Group II, n=89). The two groups were compared with respect to the various clinicopathological characteristics. The mean follow up duration was 64.9 months (13~247 months). RESULTS: Group I showed a significantly higher sensitivity than Group II for the diagnosis. The age of the patients in Group I was significantly older than those in Group II. The frequency of multifocality, capsular invasion, and the incidence of a cervical lymph node metastasis were significantly higher in Group I. Therefore, Group I had a higher proportion of stage III and IV. The percentage of high risk patients according to the AMES (Age, distant Metastasis, Extent of primary tumor, and tumor Size) category and MACIS (distant Metastasis, Age, Completeness of primary surgical resection, extrathyroidal Invasion, and tumor Size) score was significantly higher in Group I. However, there was a similar rate of locoregional recurrence, distant metastasis, and survival in the two groups. CONCLUSION: When a diagnosis of FVPTC is made preoperatively or intraoperatively, definitive thyroid cancer surgery can be applied using the corresponding extent of surgery for an ordinary papillary thyroid carcinoma. However, if no definitive diagnosis is made, then a less-than total thyroidectomy is recommended as the initial surgery, and a complete thyroidectomy is reserved only for high-risk patients.

Huge Cavernous Hemangioma of the Thyroid Gland / 대한내분비외과학회지

Cavernous hemangioma is a benign congenital vascular malformation that can affect any part of the body. However, primary hemangioma of the thyroid gland is extremely rare with only six cases reported in the literature. We report here on a case of a cavernous hemangioma of the thyroid gland in a 66-year-old man. Magnetic resonance imaging (MRI) showed a huge exophytic mass measuring 17 cm, which had replaced the left lobe of the thyroid. The histologic examination of the surgical specimen revealed a huge cavernous hemangioma.

Giant Parathyroid Adenoma in the Posterior Mediastinum / 대한내분비외과학회지

An ectopic hyperfunctioning parathyroid gland is a wellknown cause of failure of an initial surgical procedure for primary hyperparathyroidism. Primary hyperparathyroidism, which is usually asymptomatic, occasionally presents with a hyper-parathyroid crisis. Techniques for preoperative localization are of great importance to prevent or minimize negative exploration and the possible need for future additional exploratory surgery. Surgical resection is the only way of managing mediastinal parathyroid adenoma. Without removal of the involved parathyroid glands, severe hypercalcemia will progress to multisystem organ failure affecting the gastrointestinal, cardiac, renal and cerebral functions, with the mortality rate approaching 100%. We describe a patient with hyperparathyroidism that was caused by a large posterior mediastinal parathyroid adenoma.

Spine Metastases as the Initial Sign of Differentiated Thyroid Carcinoma: Two Case Reports / 대한내분비외과학회지

Bone metastases as the first manifestation of thyroid carcinoma are extremely rare. Interestingly, evaluation at appropriate initials and proper treatment will lead to satisfactory long-term survival. We report here on two such cases; the patients presented with back pain and fine needle aspiration cytology of spine lesion revealed a metastatic carcinoma. A wide excision of the bone lesion was carried out and the histopathology was consistent with features of metastatic carcinoma of the thyroid. The management of thyroid carcinoma and the subsequent bone metastases is reviewed and the controversial points are highlighted.

Surgical Aspects of Subacute Thyroiditis / 대한내분비외과학회지

PURPOSE: Subacute thyroiditis (SAT) is an uncommon, self-lemiting inflammatory disorder. If clinicians cannot rule out thyroid cancer in SAT patients with a thyroid nodule, surgical management can be considered. This study was performed to review the clinical characteristics of patients who were treated surgically for SAT presenting with thyroid nodule. METHODS: We retrospectively reviewed the clinical features of 14 cases who underwent an operation for SAT with a thyroid nodule between January 1986 and May 2006 at our institution. RESULTS: There were 3 male and 11 female patients, with a mean age of 47 years. All patients underwent surgical management prior to 1998. Twelve patients had thyroidal pain, 6 had viral prodromal symptoms, and 5 had hyperthyroidisms. Preoperative erythrocyte sedimentation rates (ESRs) (n=4) were elevated in 3 patients. Decreased uptake of radioiodine was reported in all 6 patients for whom scans were performed (n=6). Fine needle aspiration biopsy (FNAB) was performed in 4. In this study, the operative indications were clinically indeterminate thyroid nodule (n=14); lobectomy in 8, lobectomy with partial thyroidectomy in 2, lobectomy with near total thyroidectomy in 2, and bilateral total thyroidectomy in 2. Hoarseness occurred in one patient. CONCLUSION: SAT is usually managed clinically, but patients presenting with an indeterminate thyroid nodule will require surgical management even though they may have more benign characteristics. Most surgeons have to wait for the results of frozen biopsy because limited resectioning can be performed if the results are benign.

Treatment of Mediastinal Lymph Node Metastases in Differentiated Thyroid Carcinoma

PURPOSE: In case of well-differentiated thyroid carcinoma, a mediastinal lymph node metastasis is extremely rare, but can be life threatening due to its proximity to the vital organs. The consequence of radical extirpation must be balanced against the issues of tumor control, survival outcomes, functional morbidity, and the sequelae of an excessive surgical resection. The aim of this study was to clarify the clinicopathological characteristics, treatment and outcomes of patients with mediastinal lymph node metastasis in differentiated thyroid carcinoma. METHODS: Nineteen consecutive differentiated thyroid carcinoma patients with a mediastinal lymph node metastasis between June 1998 and Feb. 2004 were included in this study. All the patients underwent a trans-sternal mediastinal lymph node dissection in addition to thyroid cancer surgery. The median follow-up was 40.7 months (range, 18~97). RESULTS: The mean age was 49 years (range 31~72 years) with a male-to-female ratio of 8: 11. The surgical treatment included 11 cases of an upper mediastinal lymph nodes dissection via a partial sternotomy and 7 cases of a whole mediastinal lymph nodes dissection via a total longitudinal sternotomy. In 6 cases, the combined resection of the involved organ was added. Major postoperative complications occurred in two patients, one with leakage from a tracheoesophageal fistula and the other with a pulmonary embolism. During the follow-up period, local recurrences in the lateral cervical nodes were observed in 5 cases. The 5 year overall survival and 5 year disease-free survival were 90.5% and 63.6%, respectively. There was only one surgical mortality. CONCLUSION: These results suggest that the prognosis for mediastinal lymph node metastasis in differentiated thyroid carcinoma can be improved by an aggressive mediastinal node dissection and the appropriate thyroid cancer surgery.

Differentiated Thyroid Carcinoma Presenting Distant Metastses as a Initial Sign

PURPOSE: Distant metastases, as the initial sign of a differentiated thyroid carcinoma, are extremely rare. The clinical characteristics for such cases remain to be established. This study was performed to characterize the clinical presentation, treatments, and outcome in such patients. METHODS: Between January 1986 and February 2005, of 4,525 differentiated thyroid cancer patients, 18 presented with distant metastases as the initial sign (0.4%). These comprised of 6 men and 12 women, with a median age of 49 years (range 9~66). Of the 18 patients, 8 (44.4%), 7 (38.9%), and 3 (16.7%) disclosed symptoms from lung, bone, and brain (16.7%) metastases, respectively. The median follow-up was 92 months, ranging from 18 to 198. RESULTS: The symptoms included cough and sputum (n=5), hemoptysis (n=2) and a lung mass (n=1) from lung metastases, back pain (n=3), a palpable mass (n=2) and a pathologic fracture (n=2) from bone metastases, as well as a headache with nausea (n=3) in all cases with brain metastases. The sites of metastases were the lung only in 7 (38.9%), bone only in 7 (38.9%) and multi-organ in 4 (22.2%). The histological diagnoses were a papillary carcinoma in 10 and a follicular carcinoma in 8. All patients underwent a total thyroidectomy followed by therapeutic radio-iodine therapy (RAI) and TSH suppressive treatment. For the metastatic lesions, aggressive treatment modalities, including surgical resection (n=9), external beam radiation (n=11), gamma-knife surgery (n=1) and a combination of these, were performed. The 10 year overall and disease-free survivals were 91.7 and 51.4%, respectively. There was only one disease-related death (1.6%). Tumor multiplicity (p=0.023) and multi-organ metastasis (p=0.009) were significant predictors of a poor prognosis. CONCLUSION: Clinical symptoms, history, physical examination, imaging studies and histological confirmation of distant metastatic lesions are important in the initial diagnostic approach. Even though distant metastasis presented as the initial sign, a 10-year disease-free survival rate of 50% was obtained. Radical resection of primary and metastatic lesions combined with high dose RAI treatment and/or external irradiation lead to long-term survival.

The Significant Predicting Factors Influencing Lateral Neck Node Metastasis in Papillary Thyroid Carcinoma

PURPOSE: A lateral neck node metastasis is common in patients with papillary thyroid carcinoma. If a preoperative diagnosis is not made or is uncertain, an intraoperative biopsy for a frozen examination should be considered. The aims of this study were to evaluate the factors predicting a lateral neck node metastasis and to suggest guidelines for an intraoperative neck node biopsy. METHODS: From March 2003 to January 2006, 79 patients (7 males, 72 females) with 89 intraoperatively biopsied lateral neck nodes were enrolled in this study. The median age was 45 years. Among these patients, two or more lateral neck nodes were biopsied intraoperatively in 9 patients and one node was biopsied in the others. The clinicopathological features and radiological findings were reviewed. RESULTS: Among the 79 patients with 89 lateral neck nodes, 25 patients with 26 lateral neck nodes (29%) showed a metastasis. Univariate analysis revealed the computed tomography (CT) findings of lateral neck nodes such as a longitudinal size >1 cm (P=0.001), postcontrast Hounsefield Unit (HU) >110 (P2 cm (P=0.008), extracapsular invasion (P=0.005) had significant impact on a lateral neck node metastasis. Multivariate analysis revealed a longitudinal size >1 cm (P=0.039), postcontrast HU >110 (P110 HU were the most important factors. CONCLUSION: The most significant factors influencing lateral neck node metastasis were multifocal, bilateral, large size (2 cm < or = ), extracapsular invasion of the primary tumor, and the CT findings of lymph nodes such as a large longitudinal size (1 cm < or =), necrosis, the absence of hilum, irregular margin and increased postcontrast HU (110 < or =).

Percutaneous Ethanol Injection Therapy for Locally Recurrent Papillary Thyroid Carcinoma

PURPOSE: Percutaneous ethanol injection therapy (PEIT) has been infrequently tried to treat hepatic tumors, thyroid tumors, and primary and secondary hyperparathyroidism. We adopted this technique for treating locally recurrent papillary thyroid carcinomas. The objective of this study is to evaluate the local therapeutic efficacy, side effects and complications of the PEIT for treating locally recurrent papillary thyroid carcinomas. MATHODS: From October 2002 to September 2005, 16 papillary thyroid carcinoma patients (3 males and 13 females) with 24 histologically proven locally recurrent lesions underwent sonography-guided PEIT under local anesthesia when reoperation or other treatments were refused or contraindicated. Of the 24 nodules in 16 patients, 8 recurred in the thyroid bed, 13 recurred in the lateral neck nodes, and 3 recurred in the central neck nodes. Ethanol was injected every 3 months under sonographic guidance. The median follow-up period was 18 months (range: 7~37 months). RESULTS: All the patients tolerated the procedures well with only mild local pain. There were no major complications. Only one patient suffered from a transient vocal cord palsy. A significant decrease of tumor size was observed in all the lesions. The pre-injection diameter of the lesions ranged 5.5 to 25.0 mm (median: 9.9 mm), and this was decreased to 0 to 17 mm (median: 5.3 mm) after PEIT. Of the 4 lesions in 4 patients, the recurrent lesions disappeared completely. CONCLUSION: Our experiences suggest that PEIT appears to be an effective alternative option for treating recurrent lesions of thyroid carcinomas in the properly selected patients. A large prospective study with long-term follow-up is necessary to determine if PEIT has an impact on survival and recurrences.

Bone Metastases from Differentiated Thyroid Carcinomas

PURPOSE: Only limited information exists on the clinicopathological profiles and the treatment outcomes of bone metastases from differentiated thyroid carcinomas. Therefore the impact of treatment strategies has been inadequately investigated. The aims of this study were to evaluate the proper management and the prognostic factors that influence the long-term outcomes of patients treated for bone metastasis from differentiated thyroid carcinoma. METHODS: Twenty-two cases of bone metastases out of 3, 775 differentiated thyroid carcinomas treated at Yonsei University Medical Center between Jan. 1986 and Dec. 2004 were analyzed. The overall incidence of bone metastases from differentiated thyroid carcinomas in our series was 0.6%. There were 11 women and 11 men, with a mean age at the time of primary diagnosis of 51 years (25~71 years). The mean follow-up after diagnosis of bone metastases was 83 months (1~358 months). RESULTS: The histological diagnoses of primary tumor were 21 and 1 papillary and follicular cancers, respectively. Metastases restricted to the skeleton alone were found in 13 patients, whereas 9 patients showed associated extraskeletal distant metastases. Seventeen patients had multiple bone metastases. In 6 patients, the bone metastases were surgically removed with intention of cure. The overall survival rates at 10 years was 44.4%. From univariate log-rank survival rates analyses, capsular invasion (P=0.0014), preoperative vocal cord palsy (P=0.0097), multiple organ involvement (P=0.024) and the impossibility of surgical treatment for skeletal metastaisis (P=0.0471) were related with a poor prognosis. CONCLUSION: From the results, the survival rate was shown no significantly decline in the patients with poor prognostic factors. Therefore the therapeutic options should be individualized according to the initial clinical state and the prognostic factors. Our data also suggest that surgical resection for metastatic bone lesions and postoperative adjuvant therapy should be performed to obtain better survival rates.

Cribriform-morular Variant Papillary Carcinoma associated with Familial Adenomatous Polyposis / 대한내분비외과학회지

Cribriform-morular variant (CMV) is a rare histologic subtype of papillary thyroid carcinoma (PTC). Patients with familial adenomatous polyposis (FAP) could be associated with several comorbid diseases including thyroid cancer. Most thyroid cancers in them are PTCs, but infrequently CMV types can occur. The FAP concomitant CMV-PTCs are found predominantly in young women and reveals lower recurrence rate. Moreover, this variant shows circumscribed morphology and rarely metastasizes to node. Because the incidence of thyroid carcinoma is higher than that in general population, comprehensive evaluation of thyroid gland should be performed for the patients with FAP. Because thyroid cancer could be first manifestation of FAP, colonic screening should be considered in CMV-PTC patient. We report two cases of CMV-PTCs concurrent with FAP.

Forgotten Mediastinal Goiter / 대한내분비외과학회지

Forgotten mediastinal goiter is an extremely rare disease. It is most often the consequence of the incomplete removal of a ‘ plunging’ goiter, but it can sometimes be attributed to a concomitant, unrecongnized primary mediastinal goiter which is not connected to the thyroid. A primary mediastinal goiter(autonomous intrathoracic goiter) essentially caused by an abnormal embryonic development of the thyroid gland and a thyroid gland formation located in the thorax or the mediastinum. The differential diagnosis with ordinary recurrence was based on the absence of parenchymatous or vascular connections with the cervical thyroid gland. It is fed by local intrathoracic vessels and observed in the absence of previous thyroidectomy. Nevertheless, for primary mediastinal goiter, sternum-splitting incision will be required in most cases as troublesome mediastinal bleeding may occur which is difficult to control from a cervical collar incision. In this study we report a case of forgotten mediastinal goiter and review the various diagnostic and therapeutic problems posed by the condition. A number of possible solutions that can be implemented for this diasease are identified.

Nonrecurrent Laryngeal Nerve / 대한내분비외과학회지

The nonrecurrent laryngeal nerve is a rare anomaly that may increase the risk of nerve injury during thyroid surgery. We experienced a case of nonrecurrent laryngeal nerve seen in a 35-year-old woman with adenomatous hyperplasia on her right thyroid. The nonrecurrent laryngeal nerve was incidentally found during the right thyroid lobectomy. It directly branched from the right vagus nerve and followed a transverse path parallel to the trunk of the inferior thyroid artery. The right lobectomy was performed with a careful preservation of the nerve. Postoperatively, the review of CT scan which was taken preoperatively revealed an aberrant right subclavian artery, which arose from the aortic arch and crossed behind the esophagus. To avoid an inadvertent injury to the nonrecurrent laryngeal nerve during thyroid surgery, it is important to be aware of the possibility of a nonrecurrent laryngeal nerve, particularly when an aberrant right subclavian artery is recognized preoperatively.

Actual Five-year Survival Rate of Hepatocellular Carcinoma after Curative Resection

PURPOSE: After curative resection for hepatocellular carcinoma (HCC), the five-year survival rate ranges between 30~50%; however, this might be different from the actual survival rate. The actual 5-year survival rate and prognostic factors following curative resection for HCC were analyzed. METHODS: A retrospective analysis was performed on 63 HCC patients, who had undergone curative resection, between 1998 and 1999. RESULTS: A total of 63 cases, including 53 men and 10 women, were reviewed. The median age was 49 years old. Pathologic T stage I, II, III and IV were observed in 1, 17, 38 and 7 cases, respectively. The actual 1-, 3- and 5-year survival rates were 85.7, 69.8 and 57.0%, respectively, with a median survival time of 58 months. The actual 1-, 3- and 5-year disease free survival rates were 68.1, 51.9 and 50.2%, respectively, with a median disease free survival time of 46 months. Thirty-one patients had recurrence, mostly within one year (65%), indicating a poor survival rate, with an actual 5-year survival rate of 5%. A satellite nodule, the pT stage, recurrence of tumor, time to recurrence (within one year), and presence of extrahepatic metastasis were found to be prognostic factors influencing the survival rate of HCC patients. However, microvessel invasion caused a difference in the survival rate, but without statistical significance (p=0.08). A satellite nodule, microvessel invasion and the pT stage were found to be factors influencing the disease free survival rate of HCC patients. No statistically related factors, with the exception of the pT stage, were found in a multivariate analysis. CONCLUSION: The actual 5-year survival and disease free survival rates were 57.0 and 50.2%, respectively. The time to recurrence and pT stage were found to be factors influencing the survival rate of patients with a hepatocellular carcinoma. Further advanced studies will have to be carried out for the active treatment of HCC cases with a pT stage III or IV to reduce recurrence.

Differentiated Thyroid Carcinoma in Patients Less than 20 Years of Age at Diagnosis: Clinicopathologic Characteristics and Prognostic Factors

PURPOSE: This study investigated the clinicopathological characteristics and prognostic factors in young patients with differentiated thyroid carcinoma. METHOD: Among the 3, 837 patients with DTC who were treated in the Department of Surgery at Yonsei University College of Medicine from March 1986 to March 2005, 71 patients were less than 20 years of age when diagnosed. The mean age was 14.9 years (range, 4~20 years). There were 59 females and 12 males with a mean follow-up period of 91.8 months (range, 14~205 months). RESULTS: The cause specific and the progression-free survivals at 10 years were 100% and 80.3%, respectively. Eleven patients (15%) experienced a recurrence and 1 patient showed a progression of a pulmonary metastasis at diagnosis. Compared with 39 patients older than 15, 32 patients younger than 15 years of age tended to have a higher incidence of a N1b and M1 stage, and a lower progression-free survival rate. Univariate analysis revealed that an age < or =15 years, multicentricity, N1b stage, M1 stage, and bilateral radical neck dissection had a negative impact on the progression-free survival. However, multivariate analysis showed that the age at diagnosis and the M1 stage were independent prognostic factors for progression- free survival. CONCLUSION: Being younger 15 years and the M1 stage are the most significant prognostic factors negatively influencing the progression-free survival. The high incidence of lateral neck and lung metastasis justifies a total thyroidectomy and modified radical neck dissection, followed by postoperative 131I therapy even in patients younger than 15 years of age.