Indication for elective neck dissection for N0 carcinoma of the parotid gland: a single institution's 20-year experience.

CONCLUSIONS: Elective neck dissection (END) may not be necessary in patients with low-grade malignancy. However, currently, END should be performed in all patients with parotid carcinoma because the preoperative diagnosis of lymph node metastasis is limited and the accuracy of preoperative grade diagnosis is low.

OBJECTIVE: Our aim was to examine the indication for END in N0 patients and the extent of dissection by investigating the accuracy of diagnosing the grade and lymph node metastasis of parotid carcinoma.

PATIENTS AND METHODS: The subjects were 77 patients with parotid carcinoma. Among N0 patients, modified radical neck dissection (MRND) was conducted in those in whom the histological grade was evaluated as high, and selective neck dissection (SND) in other patients.

RESULTS: Lymph node metastasis was detected in 27 of 71 patients who underwent neck dissection. Node metastasis was detected in 19 (61.3%) of 31 patients in whom high-grade malignancy was suggested and in 8 (22.9%) of 35 patients in whom intermediate-grade malignancy was suggested preoperatively. There was no metastasis in any of the five patients in whom low-grade malignancy was suggested. Occult metastasis was noted in 8 of 51 patients. The rate at which the histological grade was accurately diagnosed before surgery was low, especially in patients with low-grade malignancy.