Clinical relevance of microvessel density in laryngeal squamous cell carcinomas

The clinical implications of microvessel density (MVD) in head and neck tumors have not been fully elucidated. We investigated the clinicopathologic correlates and prognostic relevance of MVD in a series of 122 consecutive patients with surgically treated laryngeal squamous cell carcinoma followed-up for a mean of 79 months. MVD was evaluated after CD34 immunostaining in 3 250x microscopic fields representative of the "hot spot" area, and expressed as the mean value of the vessel counts per millimeter squared. The overall median value of the intratumoral vessel count was 69.5/mm(2). In the 20 cases we analyzed, MVD increased significantly from normal to dysplastic mucosa and infiltrating carcinoma (p = 0.0001). Nineteen carcinomas (15.6%) had MVD values that were equal to or lower than the highest MVD value (52.7/mm(2)) observed in normal mucosa samples (in which the median MVD count was 34.5/mm(2), range 16.6-52.7/mm(2), mean 35.1 +/- 11.5/mm(2)) and were therefore considered poorly vascularized. Periodic acid-Schiff (PAS) staining revealed intratumoral PAS-positive connective tissue septa in 13 cases (10.7%). The patients with poorly vascularized tumors showed a tendency toward a better prognosis, but the anatomical site, tumor extension and clinical stage were the only variables significantly associated with disease-free and overall survival.