Microscopy revealed a cystic mass, partially lined by a proliferation of capillaries, characterised by closely packed thin-walled vessels. There are associated large neoplastic stromal cells with eosinophilic to clear foamy cytoplasm and prominent vacuolation. The cells show hyperchromatic nuclei. The cyst wall shows evidence of gliosis. There is no significant necrosis.
The immunohistochemical findings confirmed a cerebellar haemangioblastoma.