Background and Objectives : Thyroid carcinoma is the sixth commonest cancer in Korea and the papillary carcinoma is the most common type(88%) of the malignant thyroid tumors. Bulky DNA adducts formed by the carcinogens are repaired by DNA repair process, but failure to repair this DNA damage can cause mutations in oncogenes and tumor suppressor genes resulting in tumor formation. The xeroderma pigmentosum group C(XPC) gene is essential for this repair procedure and the XPC-PolyAT(PAT) polymorphisms may alter DNA repair capacity(DRC) and genetic susceptibility to cancer. Subjects and Methods : In a case-control study of 113 Korean patients with pathologically diagnosed thyroid papillary carcinoma and 65 control subjects, we investigated the association between the three XPC-PAT gene polymorphisms and thyroid papillary cancer susceptibility. Results : The frequency of the variant XPC-PAT allele was lower in the cases(0.349) than in the controls (0.423), but the difference was not significant(p=0.140). Using logistic regression adjusting for age and sex, risk for thyroid papillary cancer was not increased in the XPC-PAT-/+ and XPC-PAT+/+ compared to XPCPAT-/-(adjusted overall odds ratio[95% confidence intervals;95%CI]=0.52[0.26-1.03] and 0.62 [0.22-1.75], respectively; trend test, p=0.167). Conclusion : There are no relationship between the XPC-PAT polymorphism and the risk of thyroid papillary carcinoma in Korean population. Based on our results, XPC-PAT polymorphism do not modulate genetic susceptibility to thyroid papillary cancer.

Objective ： This retrospective study was designed to evaluate the anti-tumor efficacy and toxicities of the radiation therapy(RT) combined with cisplatin-based chemotherapy in locally advanced nasopharyngeal cancer(NPC). Materials and Methods ： Fifty three patients with locally advanced NPCs(AJCC stage II, III, IV) received curative RT and cisplatin-based chemotherapy. Duration of follow-up ranged from 5.5 to 201 months(median 50.8 months). Nineteen patients(35.8%) were treated with induction chemotherapy including cisplatin $100mg/m^2$ for 1 day and 5-fluorouracil $1g/m^2$ for 5 days followed by RT(Induction CTx-RT). Another 34 patients (64.2%) were treated with concurrent chemoradiation(CCRT) using cisplatin $100mg/m^2$(D1, 22, 43). Results ： Thirty-six(67.9%) and 11(20.8%) patients achieved clinical complete response and partial response, respectively. The pattern of failure was as follows：14 locoregional recurrence(26.4%) and 7 distant metastasis(13.2%). Among them, two patients(3.8%) had both locoregional and distant failure. Median overall survival(OS) and progression-free survival(PFS) were 85.5 months and 87.5 months, respectively. Five-year OS rate was 57.1%. The stage(AJCC), tumor response to chemoradiation and T stage were significant prognostic factors for OS(p=0.0113, p=0.0362 and p=0.0469). The stage(AJCC), tumor response to chemoradiation were also significant prognostic factors for PFS(p=0.0329, p=0.0424). Compared to each treatment group(Induction CTx-RT vs. CCRT), there were no significant differences in OS and PFS(p=0.7000, p=0.8261). Grade 3-4 mucositis, nausea/vomiting and hematological toxicities were noticed in 35.8%, 11.3% and 13.2%, respectively. Delayed RT over 2 weeks was inevitable in 26.5%. Seventeen patients(50%) successfully completed planned 3 courses of cisplatin in CCRT group. Conclusions ： RT combined with cisplatin-based chemotherapy in locally advanced NPC showed high response rate, good locoregional control, and survival rate. As expected, frequency of acute toxicities increased, and the patient's compliance to treatment was need to be improved. Although our data could not show additional survival benefit of CCRT compare to that of induction chemotherapy followed by RT, patients' accrual and further follow-up are required due to limitation of retrospective study.

Introduction : The sensitivity of tumor cells to radiotherapy is a critical determinant of local control and potential cure in advanced head and neck squamous cell carcinoma(HNSCC). The emergence of radioresistant tumor cells is an obstacle to cancer therapy. Most radioresistant cells have a higher proportion of cells in the Sphase of the cell cycle and a lower apoptotic fraction than radiosensitive cells. HSV replication is increased in cells that have higher S-phase fractions. NV1066 is an oncolytic herpes simplex virus type-1 mutant. We hypothesized that NV1066 replication and cytotoxicity are increased in radioresistant cells. The purpose of this study is to evaluate the antitumor efficacy of NV1066 to treat radioresistant HNSCC. Methods : Radioresistant cells were selected by treating five HNSCC cell lines with repeated conventional fractionated doses of radiation(2Gy/day), using a Cs-137 irradiator, up to a cumulative dose of 70Gy. Clonogenic cell survival and S-phase fractions were compared between radioresistant and parental radiosensitive cells. The two cell populations were then treated with NV1066 to examine viral replication, by the viral plaque assay and viral cytotoxicity. Results : Fractionated irradiation resulted in the selection of radioresistant cells. Radioresistant cells had a higher S-phase fraction(42.9%) compared to parental cells(26.2%). NV1066 replication in radioresistant cells was 7.4 times higher than in parental cells(p<0.01). Treatment with NV1066 resulted in increased cytotoxicity of 24.5% in radioresistant cells compared to parental cells(p<0.05). Conclusion : NV1066 showed increased viral replication and cytotoxicity in radioresistant HNSCC cell lines. These findings suggest a potential clinical application for this oncolytic viral therapy as treatment for radioresistant head and neck cancers.

Purpose : It has been generally accepted that lobectomy is a standard surgical procedure in treatment of benign thyroid nodules. However lobectomy may cause postoperative hypothyroidism. Most of surgeons believe that nodulectomy has its limitation in treatment of thyroid nodules due to recurrence of nodules and presence of cancer. The current study attempts to determine whether nodulectomy is justified in aspects of preservation of thyroid function, risk of recurrence and complications. Methods: Data was collected retrospectively on 74 patients undergoing thyroidectomy(single nodulectomy, n=43;bilateral nodulectomies, n=9;lobectomy with nodulectomy, n=22) for benign thyroid nodules from 1999 to 2004. All patients were evaluated for complication, postoperative thyroid function, and recurrence of benign nodule and cancer were followed by regular ultrasonographic examination for 2-6 years. Results : The pathologic results of 74 patients were nodular hyperplasia(55 patients), Hashimoto's thyroiditis(8 patients), follicular adenoma(7 patients) and papillary carcinoma(4 patients). Average operation time was 30 minutes from skin incision to specimen out. In postoperative follow-up of 70 patients, six cases(8.5%) became mild hypothyroid, and ultrasonographically detected micronodule was also six cases(8.5%). There were no other complications. Conclusion : Thyroid nodulectomy appears to have advantages of relatively few complication and simple procedure with no access to laryngeal nerves. Therefore, it may be one of treatment options in selected cases of benign thyroid nodules.

Background and Objectives : This study reports our clinicopathological experiences of major salivary gland tumors. Materials and Methods : This study included 302 patients with major salivary gland tumors who had got the diagnosis from January 1995 through December 2004. Medical records were reviewed retrospectively. Results : We found 244 benign and 58 malignant major salivary gland tumors. Among 267 parotid tumors, the most common benign parotid tumor was pleomorphic adenoma. Mucoepidermoid carcinoma, adenoid cystic carcinoma, and acinic cell carcinoma were three most common parotid malignancies. Among 33 submandibular gland tumors, 20 cases were benign and 13 were malignant. There were one benign and one malignant sublingual gland tumors. The duration of symptom of submandibular gland tumors was longer than that of parotid tumors. Most patients presented with asymptomatic mass. Seventy-one percent of salivary gland malignancies underwent postoperative radiation therapy. Five-year disease free survival rate of parotid malignant tumors seemed to be higher than that of submandibular one, although there was no statistical significance. Conclusion : Malignancy rate of each salivary gland followed old axiom that it is inversely related with the size of gland. Submandibular gland tumor tends to be delayed to reach diagnosis. Clinicians must be alert about this finding because submandibular gland tumors are known to have poorer prognosis than parotid tumors.

Pilomatrixoma is an uncommon tumor arising from hair follicles. Commonly occur in children and most frequently in the head and neck region. It can be mistaken for parotid gland tumor, dermoid cyst, or epidermoid cyst, especially when large lesions develop over the periauricular area, difficulty discerning them from lesion developing within the superficial lobe of the parotid gland may occur. We experienced two cases of pilomatrixomas mimicking parotid gland tumor. Although their histologic appearance is characteristic, they may be clinically misdiagnosed. However, combining clinical information with the distinct histologic features should lead to the correct diagnosis.

Epithelial-myoepithelial carcinoma is rare, low grade malignant tumor of the salivary glands that exhibits a dual composition of epithelial and myoepithelial cells. Most of these tumors arise in the parotid gland, and only few occur in the submandibular gland or minor salivary glands. We describe here a rare case of epithelialmyoepithelial carcinoma arising from a minor salivary gland in the nasopharynx, one of the most unusual locations. The clinical and biological behavior of this tumor is not yet known.

Intrathoracic goiters can be classified anterior and posterior mediastinal goiter with its locations. Most intrathoracic goiters are retrosternally situated in the anterior mediastinal compartment. Posterior mediastinal goiters are rare, but might present a difficult diagnostic and surgical problem. Although thyroid goiters are nearly always amenable to a cervical approach, posterior mediastinal goiters may require a combined cervicothoracic approach with sternotomy or thoracothomy. We herein describe a case of posterior mediastinal goiter which was excised only by cervical approach. The relevant literature is briefly reviewed.

Trichilemmal carcinoma is a rare malignant neoplasm of the hair follicle from the outer root of the hair follicle sheath. This tumor can be misleading, and a false diagnosis of a squamous cell carcinoma. We report a case of trichilemmal carcinoma with a review of literature. The patient presented with an exophytic well circumscribed nodular mass on the left auricle, which was detected 6 months ago. Histopathologically, the tumor consisted of atypical clear cells which contained abundant glycogen. The tumor cells shows lobular growth pattern with necrosis, foci of trichilemmal keratinization and peripheral pallisading. Total excision and repair with full-thickness skin graft was done with minimal surgical morbidity. The patient has been free of recurrence or metastasis for 8 months.

Schwannomas are benign tumors arising from the nerve sheaths of peripheral, autonomic and cranial nerves. Between 25% and 45% of all schwannomas occur in the head and neck region but only 4% involve the nasal cavity and paranasal sinus. Moreover, schwannoma of the pterygopalatine fossa is extremely rare. We present a case of schwannoma of the pterygopalatine fossa in a 43-year-old woman. The patient was surgically managed with endoscopic transnasal approach combined with transantral approach. After 16 months, the patient shows no evidence of recurrence.

Extramedullary plasmacytoma is rare tumor of plasma cell tumor, which involve soft tissue without any signs of systemic spread and occurs predominantly in the head and neck, especially the nasal cavity and the paranasal sinuses. Ten to twenty percent of extramedullary plasmacytoma have regional lymph metastasis at the time of diagnosis and approximately one third of patients with extramedullary plasmacytoma will subsequently develop multiple myeloma during long-term follow-up. Primary treatment modality is moderate-dose radiation and surgery is rarely used. Extramedullary plasmacytoma has good prognosis, but requires long-term systemic evaluation and follow-up. We report a case of extramedullary plasmacytoma of the sinonasal cavity with a review of literature.

Tumors rarely arise in the sublingual salivary glands. They should be considered malignant until proved otherwise. Adenoid cystic carcinoma is most commonly encountered malignant tumor of the sublingual gland. We report a case of adenoid cystic carcinoma arising from the sublingual gland. Moreover, the sublingual gland had anatomic variation of main duct(Bartholin's duct) which is connected to Wharton's duct.

Pulsed dye laser(PDL) is originally designed for the treatment of vascular lesions but also effective in improving the quality and appearance of surgical scars. Recently, 595nm Pulsed dye laser(V-beam laser), which has the advantage of deeper tissue penetration and lesser amount of purpura, is spotlighted as a new option for the treatment of surgical scar. The authors treated a surgical scar of a female patient with V-beam laser for 3 times between 4 and 12 weeks after surgery. Subjective satisfaction was improved with visual analogue scale (VAS) and objective improvements were found in parameters of vascularity, pliability and height with Vancouver Scar Scale(VSS). We report the effectiveness of V-beam laser in surgical scar of Asian patient and plan the prospective study with larger scale.

Bilateral chylothorax as a complication of radical neck dissection is extremely rare. Early diagnosis of chylothorax is important due to the consequences on metabolic & cardiopulmonary conditions. This present report describes our recent experiences with two cases of bilateral chylothorax following left modified radical neck dissection that was treated successfully by conservative management.

Thyroid hemiagenesis is a very rare congenital anomaly in which one thyroid lobe fails to develop. The cause of thyroid hemiagenesis is still unknown. The true prevalence of thyroid hemiagenesis is not known, but it is estimated to be from 0.05% to 0.2% in normal children. Thyroid hemiagenesis is common in female with the left lobe being absent. The common disease in the remaining lobe is hyperthyroidism, benign adenoma, a toxic multinodular goiter, chronic thyroiditis, primary myxedema, and rarely carcinoma. Tc-99m pertechnate scintigraphy, ultrasonography and computerized tomography can be used to confirm this anomaly. Here we report three cases with left lobe agenesis. Two of them were euthyroid state while the other hypothyroid patient had a ectopic lingual thyroid.

Papillary thyroid carcinoma is rarely associated with macroscopic vascular invasion or tumor thrombosis. Especially, superior vena cava syndrome(SVCS) resulted from tumor thrombosis of papillary thyroid carcinoma is extremely rare. We present herein a case of SVCS caused by tumor thrombosis from papillary thyroid carcinoma which was successfully solved by intravascular placement of self-expandable stent in 74-year-old woman.