ABSTRACT
<p><b>OBJECTIVE</b>To evaluate relative factors affecting contralateral cervical lymph node metastasis in piriform sinus carcinoma.</p><p><b>METHODS</b>Ninety-six cases of piriform sinus carcinoma with no preoperative treatments were selected. The contralateral cervical lymph node metastasis and relative factors were analyzed during operation or postoperative follow-up. The contralateral cervical metastasis was defined as followed: 1 contralateral cervical metastasis was confirmed pathologically after bilateral neck dissection (pN2c) or 2 contralateral cervical metastasis was found firstly during postoperative follow-up and the recurrence of primary lesion was excluded.</p><p><b>RESULTS</b>The incidence of contralateral cervical metastasis was 32% (31/96). According to the T stage, the incidence of contralateral cervical metastasis was T1: 0% ,T2: 18%, T3: 37%, T4: 32% and to the N stage N0: 12%, N1: 13%, N2a: 17%, N2b: 39%, N2c: 100%, and N3: 75%. For primary lesions beyond midline the incidence of contralateral cervical metastasis was 52% but for those remaining on ipsilateral side it was 18%.</p><p><b>CONCLUSIONS</b>Contralateral cervical lymph node showed higher metastatic incidence with higher T and N stage. When the primary lesions invaded beyond midline, the contralateral cervical metastasis increased greatly and neck dissection should be selected positively.</p>