The relationship of primary tumor thickness in carcinoma of the tongue to subsequent lymph node metastasis

Objectives: To study whether primary tumor thickness of stage I/II tongue carcinoma provides information about subsequent lymph node metastasis. Methods: Twenty consecutive patients with T1N0M0 or T2N0M0 tongue carcinoma were studied. Primary tumor thickness was measured with post-contrast helical computed tomography or intra-oral sonography. Cervical lymph nodes were evaluated periodically with sonography at intervals of 2-4 weeks. Sensitivity, specificity and accuracy for subsequent metastasis was calculated. Results: Positive sonographic findings appeared in nine nodes of nine patients during this follow-up period. Eleven patients underwent neck dissections, and nine had histopathologically positive nodes. Nine patients had no sonographic findings of metastasis during a minimum follow-up period of 20 months. Primary tumor thickness varied from 3 - 16 mm. Using 5 mm as a cut-off thickness, the sensitivity, specificity and accuracy for subsequent lymph node metastasis were 64, 100 and 75% respectively. Conclusions: Patients with stage I/II tongue carcinoma which is more than 5 mm thick are more likely to develop lymph node metastasis.