4.

RESULTS:A total of 374 patients having undergone 406 operations was identified. Their ages varied from 14 to 94 years (mean = 57.4 years), with 255 men (68.2%), and 295 out 366 Caucasian (80.6%). A majority had tumors of the tongue and/ or floor of mouth (55.6%), while 20.3% had lip cancer. Squamous cell carcinoma was found in 90.3%, and glandular carcinoma in 4%. T4 tumors in 39.6%, Tis or T1 lesions in 15.2% of all patients. Nearly 62% had no regional metastases, and the relative incidence in young patients (40 years or younger) reached 8.6%. CONCLUSION: In spite of the predominance of locally advanced tumors, a majority of patients had no neck metastases. The 31.8% incidence in females indicates an increasing incidence of oral cavity cancer among women when compared to previous periods at the same institution. KEYWORDS: Head and neck neoplasms. Mouth neoplasms. Neoplasm metastasis. Population at risk. Epidemiology.Cancer of the oral cavity represents 2.6% of all malignancies affecting the Brazilian population according an estimate from the Brazilian National Cancer Institute (INCa) for 2003. Oral cancer is the eighth most common cancer in Brazil and occupies the sixth place when only men are considered. Regarding mortality, a total of 2.8% of deaths by cancer was due to malignancies in the mouth, which places oral cancer in the ninth place for mortality among all malignant tumors.

Intraoperative nerve monitoring of the EBSLN aids in EBSLN identification and provides electroneuromyographic information in 80 % of cases. The laryngeal head of the sternothyroid muscle is a useful landmark to locate EBSLN.

Non recurrent laryngeal nerve is a rare anatomical variation with an incidence in literature of 0.3 % to 1.6 % on the right side. This variation places the nerve at risk of inadvertent injury during head and neck surgeries. Awareness about this abnormality and meticulous dissection of the nerve in every case is the only way to stay safeguarded. Here we present a case of right non recurrent laryngeal nerve in a 32 years old female patient who underwent near total thyroidectomy for nontoxic multi nodular goitre. During surgery, the right recurrent laryngeal nerve could not be identified in its normal location. Further dissection revealed a non recurrent laryngeal nerve arising from the vagal trunk. A CT angiogram was done post operatively and showed an anomalous origin of the right subclavian artery as the last branch of the aortic arch and a bi-carotid trunk. Every surgeon operating on the neck should be aware of and anticipate this variation of the recurrent laryngeal nerve especially when the nerve cannot be identified in the normal location. Case report: A 32 yr old female presented with a swelling in front of the neck .clinical examination showed a thyroid swelling with multiple palpable nodules in both lobes which were firm in consistency and had no retro sternal extension. There were no palpable cervical lymph nodes. An USG of neck confirmed this findings. The patient was clinically and biochemically euthyroid. FNAC was consistent with nodular goiter. On direct laryngoscopy vocal cord function was normal bilaterally. With the diagnosis of euthyroid multinodular goitre the patient was posted for near total thyroidectomy. During thyroidectomy the recurrent laryngeal nerve could not be identified in its usual location. Instead there was a white cord like structure transversing parallel to and between the branches of the inferior thyroid artery. This structure was traced laterally in to the carotid sheath and was found to arise from the right vagal trunk. Medially this structure was found to enter the crico thyroid membrane and hence identified to be non recurrent laryngeal nerve. Thyroidectomy was completed and the recurrent laryngeal nerve on the left side had a normal course. The postoperative period of the patient was uneventful and a vocal cord examination showed equal movement on both sides. A CT angiogram done retrospectively revealed an anomalous origin of a right subclavian artery as the last branch of the aortic arch. This artery crossed from left to right posterior to the esophagus. Moreover the right and left common carotid artery originated from the aortic arch as a common trunk (bicarotid trunk) which was the first branch of the aortic arch. A normal left subclavian artery arose between the bicarotid trunk and the anomalous right subclavian artery. The patient did not have any difficulty in swallowing (dysphagia lusoria) on retrospective questioning.