Clinicopathological considerations on angiogenic potential in neuroblastoma Schwannian stroma - poor tumours.

The aim of the study was to determine microscopic angiogenic parameters of neuroblastoma (NB) Schwannian stroma-poor tumours. Furthermore the associations between vascular parameters and clinicopathological features of tumours and basic prognostic factors were analysed. Examined tissue samples from 62 NB came from 39 untreated and 23 chemotherapy pretreated tumours. The clinicopathological data comprised: patients' age, gender, survival, tumour site and stage, tumour histology and MYCN status.The morphological analysis of the angiogenic potential concentrated on examination of vascular patterns - classical type or pathological angiogenesis with mural microvascular proliferation (MVP). The quantitative study included semi-automatic assessment of vascular density (VD) in CD34 stained tumour sections. Pathologic angiogenesis with MVP, including simple and/or glomeruloid type, was encountered in 25 cases and was more frequent in differentiating histology subtype and extraadrenal tumours. VD value ranged from 56 to 385 vessels/mm2 (median 149). Higher VD was connected with younger patient's age. In untreated tumours VD was significantly higher in infants than in children over one year of age. Pathologic type angiogenesis and lower VD were found to be associated with shorter survival. Our study confirmed high vascularization of NB and revealed common occurrence of vascular pattern with MVP. Angiogenic potential in the analysed group showed diversity related to some clinicopathological tumour features. This points toward heterogeneity of NB tumours in vascular aspects, possibly affecting tumours' reactivity to antiangiogenic therapy.