Clinicopathologic growth factors in vestibular schwannomas: a morphological and immunohistochemical study of 69 tumours

Tumour growth of vestibular schwannomas is still difficult to predict. The aim of our study was to determine whether any defined histopathological fea ture was correlated with the clinical course. We did a retrospective study with 69 paraffin-embedded rumours to establish whether the number of vessel s, blood cells extravasation or degree of inflammation, all semi-quantitati vely assessed, could be indicative of potential of growth. An immunohistoch emical study was: also performed with an endothelial marker CD34, the leuko cyte common antigen CD45 and the estrogen and progesterone hormone receptor s. All these parameters were correlated with patient's age, duration of sym ptoms (d), with a clinical growth index (CLI = tumour size/d). No clinical parameters proved to be predictive of tumour growth. Tumour size was signif icantly (p= 0.01) related to the number of vessels and we found a significa ntly relationship between the clinical growth index (CLI) and total number of vessels, especially when duration of symptoms lasted less than 1 year (p <0.001). However, we found no relationship between duration of symptoms or CLI and CD34 index. The degree of inflammation was significantly correlated (p = 0.007) with duration of symptoms when it lasted more than 1 year. The CD45 index and the semi-quantitative evaluation of the inflammation were w ell correlated (p = 0.001). No estrogen receptors antigenic site was detect ed and only seven tumours expressed progesterone receptor in a Few cells wi thout any significant clinical value. These results suggest that vessel den sity is determinant for sporadic acoustic neuroma growth especially For a s hort clinical course.