[Round table: Infratentorial hemangioblastoma].
Posterior fossa is the main location of hemangioblastomas of the CNS. Etiological, gross anatomical, clinical and thérapeutic study performed by F. Resche et al. is based on analysis of 20 large series and 624 separated cases of the literature and on results of a cooperative study of the S.F.N.C. (Société française de Neurochirurgie) which collected 262 cases. It is the largest series gathered up to the present. Among the S.F.N.C. series there were 151 males and 111 females. The age ranged from 2-71 with two peaks in 31-35 and 46-50 in the male population. The mean age at the time of diagnosis is 38 but lower in the female group than in the male one. The mean age is significantly lower in familial cases. Cerebellum is the main location of infratentorial hemangioblastomas. Brain stem hemangioblastomas occurred in less of ten per cent of cases (3,77% in the S.F.N.C. series). Solitary tumors are located in the cerebellar hemipheres in about 80 per cent of cases, where they are of macrocystic type (type 2) in a proportion of two third; vermian tumors are equally of cystic and solid (type 3 and 4) types. Whatever their gross anatomic type and location, infratentorial hemangioblastomas usually have a superficial margin at the leptomeningeal layer. Associated axial and extra-axial lesions are analysed. Angiomatosis retinae are in 30-40% of cases the first manifestations of disease, occurring before infratentorial tumor. Pathogenic features are studied. Lethal potential of renal carcinomas and pancreatic nesidio-blastomas of Lindau's disease is pointed out. Histo and cyto pathologic aspects of infratentorial hemangioblastomas are analysed by J. Hassoun. Morphological (photonic and ultra-structural) characteristics are seen and an attempt on histogenetic interpretation is given. From a clinical point of view it is important to note that hemangioblastomas, although they are vascular tumors, are exceptionally revealed by an intrathecal bleeding. The most common initial symptoms are manifestations of increased intracranial pressure without or only with light signs of cerebello-vestibular disturbances. (F. Resche et al.) Potential occurrence of polycythemia in cerebellar hemangioblastoma is a well-known fact. J.P. Caron et al. report a case of a cerebellar hemangioblastoma with polycythemia where plasmatic, C.S.F. and saline extract tumor erythropoietin levels have been measured. Elevate erythropoietin levels were found in the C.S.F. and the tumor suggesting true ectopic hormonal production which is responsible for the polycythemia encountered in this patient.(ABSTRACT TRUNCATED AT 400 WORDS)
D002525:Cerebellar Cortex / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D005134:Eye Neoplasms / Q000473:pathology / Q000556:secondary; D005260:Female; D006394:Hemangiosarcoma / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D012160:Retina / Q000473:pathology; D013120:Spinal Cord Neoplasms / Q000473:pathology / Q000556:secondary
Table ronde: Les hémangioblastomes infratentoriels.