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Background: The location of the parotid gland tumor can affect the duration and difficulty of operation. Therefore, accurate preoperative evaluation of tumor location can affect surgical outcomes., Methods: Results in 100 patients with parotid gland tumors who underwent parotidectomy between January 2000 and October 2005 were retrospectively reviewed. Tumor location was determined relative to four landmarks--facial nerve (FN) line, Utrecht (U) line, Conn's arc (CA), and retromandibular vein (RV)--on computerized tomography (CT) scans, and confirmed by intraoperative findings. The accuracy of each landmark was evaluated. Correlations between accuracy and tumor size were determined for tumors < or =2 cm and >2 cm in diameter., Results: Of the four landmarks, the U line was the most accurate (94%), sensitive (89.3%), and specific (97.7%) in predicting tumor location. However, for tumors < or =2 cm in diameter, FN line (p = 0.022) and RV (p = 0.028) were significantly more accurate than U line and CA., Conclusion: Although the U line was the most accurate in predicting the location of parotid gland tumors, landmarks predicting accurate tumor location should be selected according to tumor size.

Zuckerkandl's tubercle (ZT) is a well-documented anatomical structure. This study evaluated ZT anatomical characteristics in terms of the recurrent laryngeal nerve (RLN) and the superior parathyroid (SP). The study involved 325 (10 with benign tumors and 315 with malignancies) patients who underwent thyroidectomy between February and June 2007. ZTs were classified according to size: Grade 0 (unrecognizable), Grade I (10 mm). The incidence and size of the ZT and its positional relationship to the RLN and SP were investigated during thyroid surgery. ZTs were identified in most patients (right 89.3%, left 85.6%). The distribution of ZTs according to grade was as follows: Grade 0, right 10.7% and left 14.4%; Grade I, right 7.9% and left 11.1%; Grade II, right 43.5% and left 38.5%; and Grade III, right 37.9% and left 35.9%. The most common RLN course was in a groove between the ZT and the main body of the thyroid. The majority of SPs were cranial to the ZT which was located at the 1 or 2 o'clock position (96.1%) in the left, and at 10 or 11 o'clock (95.2%) in the right. The smaller the size of the ZT, the greater the distance between the ZT and the SP. There was a constant relationship between the ZT and RLN and SP. Therefore, an identification of ZT and an understanding of the relationship between the ZT and RLN and SP are essential for performing safe thyroid surgery.

Objective: The purpose of this study was to determine which types of macrocalcifications are associated with thyroid carcinoma and to assess the role of other suspicious sonographic findings in thyroid nodules with macrocalcifications., Methods: Our Institutional Review Board approved this retrospective study, and informed consent was not required. We reviewed sonographic findings of thyroid nodules in 722 patients that underwent thyroid surgery in our institution between March 2006 and August 2006. Sonographic results were grouped into 3 types of macrocalcifications. Each lesion was evaluated on the basis of other suspicious sonographic criteria, including marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape. Sensitivity and specificity based on sonographic criteria were calculated and compared among the subtypes of macrocalcifications., Results: One hundred seventy-four nodules showed macrocalcifications; 116 were malignant, and 58 were benign. Among the macrocalcification categories, solitary calcifications were more common in benign thyroid lesions, whereas coarse calcifications not otherwise specified were more common in malignant lesions (P < .05). Although the risk of malignancy was 17.2% in cases with no suspicious sonographic findings, the risk of malignancy was up to 82.8% in cases with at least 1 of the sonographic criteria (P < .05). On the basis of the suspicious sonographic criteria, the overall sensitivity was 82.8%. There was no statistically significant difference in sensitivity among the macrocalcification subtypes (P > .05)., Conclusions: Suspicious sonographic features such as marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape can play important roles in differentiating benign and malignant thyroid nodules with macrocalcifications.

We investigate the current status of endoscopic thyroidectomy in Korea. A representative questionnaire was sent to 21 members of the Korean Association of Endocrine Surgeons who were thought to be performing endoscopic thyroidectomy. All the reply letters were collected and analyzed. The response rate was 95%. A total of 1616 cases of endoscopic thyroidectomy were performed from the year 1998 to the year 2005. The patients included 71 men and 1545 women, with a mean age of 36.17 years. The mean operation time was 124.18 minutes and overall length of hospital stay was 4.31 days. Thyroid lobectomy and nodular hyperplasia were the most common procedures and prominent pathologic findings. Axillary approach was the most popular operative approach method. Gas insufflation and skin-lifting gasless method were used in 800 cases and 816 cases, respectively. Postoperative complication rate was 14.2%. Skin paresthesia was the most common complication. Conversion rate to conventional thyroidectomy was 2.2%. Korean experiences show that endoscopic thyroidectomy is a technically safe and feasible procedure. It is considered to be an important surgical tool that can be further progressed and that also has an excellent potential in a management of thyroid neoplasm.

The purpose of this study was to retrospectively evaluate the efficacy of ultrasonography-guided percutaneous ethanol injection (PEI) for neck recurrence of papillary thyroid carcinoma (NR-PTC). Twenty-seven patients (19-80 years old; mean, 53.2) with 47 NR-PTCs were treated by PEI and were followed-up (14-38 months; mean, 28.2). Ethanol (99%) was repeatedly injected with adjusting needle position until the entire volume of NR-PTC was ablated. All patients received follow-up ultrasonography at 3-6-month intervals, and the percent volume decrease was measured. The NR-PTCs with decreased volume and no tumor vascularity on power-Doppler study were regarded as treatment-effective. The NR-PTCs with stable or enlarged volume or with tumor vascularity were considered as treatment-failed, in which case PEI was repeated. The number of sessions and the total volume of ethanol per NR-PTC, and the volume of ethanol per session per NR-PTC were evaluated. All NR-PTCs significantly decreased in volume (range, 30-100%; mean, 93.6%). The mean number of sessions, the total volume of ethanol per NR-PTC, and the mean volume of ethanol per session per NR-PTC were 2.1 sessions (range 1-6), 2.4 ml (range 0.3-10.1), and 1.1 ml/session (range 0.3-3.0), respectively. PEI appears to be an alternative option for controlling NR-PTCs in the selected patients who are poor surgical candidates.

Objective: Percutaneous ethanol injection therapy (PEIT) has been used to treat various human neoplasms. We evaluated the local therapeutic effect of PEIT in recurrent thyroid cancers., Design: From October 2002 to September 2005, we performed ultrasound-guided PEIT on 24 recurrent lesions (eight in thyroid beds and 16 in neck nodes) of 16 papillary thyroid carcinoma patients. Ethanol was injected at 3-month intervals under sonographic guidance., Main Outcome: All patients tolerated PEIT well with only mild local pain, although one patient complained of transient hoarseness after the procedure. The median diameter of lesions was significantly reduced, from 9.9 mm (range, 5.5-25.0 mm) to 5.3 mm (range, 0.0-17.0 mm) by PEIT. Four recurrent lesions disappeared sonographically., Conclusion: PEIT may be an alternative treatment option for locally recurrent thyroid carcinomas in properly selected patients. However, a prospective, long-term follow-up study is necessary to determine the effect of PEIT on patient survival and tumor recurrence.

Surgery for thyroid disease requires skin incisions that can result in postsurgical problems such as prominent scars, adhesions, hypesthesia, and paresthesia in the neck. To overcome these problems we performed gasless endoscopic thyroidectomy via an axillary approach. Between May 2004 and April 2005, 30 patients underwent gasless endoscopic thyroidectomy via an axillary approach. The mean operating time was 126.8+/-32.4 minutes, and the mean length of hospital stay was 4.3+/-1.1 days. No cases required conversion to open surgery and none involved significant intraoperative complications. Three patients (10.0%) complained of slight hypesthesia or paresthesia in the anterior chest wall, and only 2 patients (6.7%) complained of discomfort while swallowing 4 months after surgery. All patients were satisfied with the cosmetic results. Gasless endoscopic thyroidectomy via an axillary approach is feasible and safe and provides excellent cosmetic results with a minimal degree of postoperative complaints.

Purpose: To determine the role of adjuvant external-beam radiotherapy (EBRT) in the management of patients with well-differentiated thyroid cancer invading the trachea., Methods and Materials: Of 1,098 thyroid cancer patients, 68 (6%) were found to have tracheal invasion, and they all received "shave" excision of the tracheal cartilage. Among them, 12 patients had no postoperative residuum, 43 patients had microscopic residuum, and 13 patients had macroscopic residuum. All patients were divided into two groups according to treatment modality with or without EBRT; (1) the control group (n = 43) and (2) the EBRT group (n = 25)., Results: The locoregional recurrence rate for EBRT patients was much lower than that of control patients (51% for the control group vs. 8% for the EBRT group) (p < 0.01). The 10-year local progression-free survival rate for the EBRT group was significantly better than that of the control group (89% in the EBRT group vs. 38% in the control group) (log-rank, p < 0.01). The use of adjuvant EBRT after conservative surgery was an independent prognostic factor in univariate and multivariate analyses., Conclusions: External-beam radiotherapy was found to be effective, particularly in patients with thyroid cancer invading the trachea with microscopic or gross residuum after conservative surgery.

Purpose: To prospectively assess the effectiveness of total parathyroidectomy and autotransplantation using a subcutaneous injection technique to treat secondary hyperparathyroidism., Methods: We used this method to treat 14 patients with secondary hyperparathyroidism. The short-term outcome, up to 16 months after surgery, was monitored by measuring calcium, inorganic phosphorus, intact parathyroid hormone (iPTH), and alkaline phosphatase levels. We considered a graft viable when the ratio of iPHT in antecubital venous blood from the grafted arm to that from the nongrafted arm exceeded 1.5., Results: Autografted parathyroid tissue was functional in 12 (85.7%) patients. An iPTH ratio > or =1.5 in the grafted arm relative to the nongrafted arm was observed from 2 weeks after surgery, peaking at 1 month. The grafted tissue continued to be biochemically functional 16 months after surgery in 12 patients., Conclusion: These findings suggest that total parathyroidectomy and forearm autotransplantation using the subcutaneous injection technique is a possible alternative to Wells' method for surgical treatment of secondary hyperparathyroidism.

Background: Among the most promising new therapies for thyroid cancer are the histone deacetylase inhibitors. Valproic acid (VA) is an anticonvulsant that inhibits histone deacetylase activity at nontoxic concentrations. We hypothesized that VA would have antineoplastic effects on human thyroid cancer cells., Methods: We treated 1 papillary and 3 follicular thyroid cancer cell lines with VA (0.5-2 mmol/L) for 24 to 72 hours. Cell proliferation was measured with a cell proliferation assay kit. Annexin V-fluorescein isothiocyanate was used to quantitate cells that were undergoing apoptosis. Quantitative polymerase chain reaction was used to measure expression of apoptosis-regulatory and differentiation genes., Results: VA inhibited growth in all cell lines by 26% to 59% at 48 hours and up to 77% at 72 hours. Nineteen percent to 30% of VA-treated cells underwent apoptosis, compared with 4% to 8% of the control cells. Expression of pro survival genes bcl-2 and bcl-xl was down-regulated by 10% to 60%; expression of the proapoptosis gene bax was up-regulated by 23% to 85%. Sodium-iodide symporter and thyroglobulin messenger RNA expression were up-regulated by 93% to 370% in follicular cell lines but remained unchanged in the papillary cell line., Conclusion: VA inhibits growth, induces apoptosis, and modulates apoptosis-regulatory and differentiation gene expression in thyroid cancer cells. These findings suggest that VA may be useful clinically for patients with thyroid cancers of follicular cell origin.

Among the most promising new antineoplastic therapies for poorly differentiated or undifferentiated thyroid cancer are the histone deacetylase inhibitors and the peroxisome proliferator-activated receptor (PPAR)-gamma agonists. These two classes of drugs have been shown to inhibit growth and induce apoptosis and redifferentiation in a variety of hematologic and solid cancer cell lines and animal models. In this article we review the molecular mechanisms, in vitro and in vivo studies, and clinical applications of the histone deacetylase inhibitors and PPAR-gamma agonists in the treatment of thyroid cancer.

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 0.8 cm. 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.