[Strategy of neck dissection in parotid cancer]

We conducted definitive surgery on 45 patients with untreated primary parotid cancer from 1975 to 1995, and evaluated methods of neck dissection and results of treatment. All 14 with clinical neck lymph node metastasis underwent ipsilateral radical neck dissection and only 1 developed neck lymph node recurrence at the peripheral dissected site. Of 31 patients without clinical neck lymph node metastasis, 27 of 19 of 36 with high-grade malignancy and 12 of 24 with T3 or T4 did not undergo prophylactic neck dissection and developed latent neck lymph node metastasis in 2 cases (7.4%). Whereas in most cases we achieved good control of the primary site but neck lymph node recurrences occurred, recurrent sites were observed all around the ipsilateral neck and prognosis were very poor if neck dissection was conducted as secondary treatment. Although histopathological diagnosis was considered feasible for predicting occult neck lymph node metastasis, correct diagnostic with fine needle aspiration cytology revealed only 21.8%. Pathological positive lymph nodes in 15 patients who underwent neck dissection were detected all over (level I to V) the ipsilateral neck and the recurrent positive rate at level II was 100%. Based on the above results, we conclude that (1) in cases with neck lymph node metastasis in preoperative evaluation, ipsilateral radical neck dissection is mandated, and (2) in cases without neck lymph node metastasis, prophylactic neck dissection is not usually needed. When pathological results of frozen section from intraoperative jugulodigastric nodal sampling are positive, ipsilateral radical neck dissection is mandated.