Histopathological predictors of occult lymph node metastases in supraglottic squamous cell carcinomas

Lymph node metastasis appears to be the most important factor determining survival in patients with squamous cell carcinoma of the larynx. Supraglottic laryngeal carcinomas have a known tendency to metastasize to cervical lymph nodes because of the extensive lymphatic network present. This retrospective cohort study was conducted to define possible histopathological parameters affecting cervical lymph node metastasis and then using these parameters to create a scale to predict occult lymph node metastasis in supraglottic squamous cell carcinoma. The pathological slides of 61 operated patients were reevaluated for tumor grade, lymphatic-vascular invasion, invasion pattern of tumor margins, perineural invasion and lymphocytic infiltration. Grade (P < 0.001), lymphatic-vascular invasion (P < 0.001) and tumor margins (P = 0.007) were found to be closely associated with neck metastasis. To define the risk factors for occult metastasis, a grading scale was created by using grade (G), lymphatic-vascular invasion (L) and tumor margin (M) findings of patients. None of the patients with a GLM value of zero developed occult metastasis. On the other hand occult metastasis was found in 58.8% of N0 patients with a GLM value that was more than zero. These findings indicate that patients with high-grade tumors having infiltrating borders and lymphatic-vascular invasion have a high risk for occult metastasis so that elective treatment of the neck either by neck dissection or radiotherapy should be added to therapy. Serial sections of specimens are needed to avoid missing metastatic loci of disease.