Lymphatic Vessel Density and survival. Disease specific survival curves for pharyngolaryngeal squamous carcinoma patients (A) or laryngeal carcinoma patients (B) stratified by the presence of tumour emboli inside lymphatics. pN0 HNSCC patients (C) or pN0 laryngeal carcinoma (D) stratified according to LVD (null-low vs. high). The number of patients remaining after every ten/twenty months period is indicated along each curve. Log-rank test significance is indicated.