Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 51, Num. 3, 2003, pp. 373-375

Neurology India, Vol. 51, No. 3, July, 2003, pp. 373-375

Hemangioblastoma: A study of radiopathologic correlation

Sundaram C, Rammurti S, Reddy JJ, Prasad SS, Purohit AK
Nizams Institute of Medical Sciences, Panjagutta, Hyderabad

Correspondence Address:
Nizams Institute of Medical Sciences, Panjagutta, Hyderabad
drjmk@sol.net.i

Code Number: ni03121

ABSTRACT

Computerized tomography (CT) scan and operative observations, and histolopathogical findings of 25 cases of intracranial hemangioblastoma were correlated. Solid hemangioblastomas showed a large number of thin-walled capillaries and abundant stromal cells with eosinophilic cytoplasm. Tumors with a cystic component and a mural nodule had a large number of stromal cells with vacuolated cytoplasm and microcysts.

INTRODUCTION

Hemangioblastomas are benign tumors of the central nervous system and account for 1-2.5% of all intracranial tumors. They commonly occur in the cerebellum (83­86%) and account for 7-12% of all primary posterior fossa tumors.[1],[2],[3],[4] We evaluated 25 cases of intracranial hemangioblastomas and correlated their radiological, operative and histopathological findings.

MATERIAL AND METHODS

Twenty-five cases of histologically verified intracranial hemangioblastomas treated during the period 1988 to 1995 were evaluated.

The histologic diagnosis was made according to the criteria laid down by Russel and Rubinstein (1989),3 as a fine meshwork of capillaries with varying proportions of stromal cells, either with eosinophilic cytoplasm or with vacuolated cytoplasm. Microcyst, nuclear pleomorphism and thick-walled blood vessels were also seen.

Histologically, the proportion of the thin-walled blood vessels to the thick-walled blood vessels, stromal cells with eosinophilic cytoplasm to the stromal cells with vacuolated cytoplasm and the presence or absence of microcysts and nuclear pleomorphism were observed.

RESULTS

Of the 25 cases of haemangioblastomas studied, the cerebellum was the primary site in 22 cases (88%) and the cerebrum in 1 case (4%). In 2 cases the tumor was primarily located in the fourth ventricle. One of these cases has been documented earlier.[5] There was male preponderance with a male to female ratio of 3.17:1. The age at presentation ranged from 8 to 65 years and 17 cases were in the 3rd through the 5th decade of life. One case with Von Hippel Lindau syndrome had bilateral hemangioblastomas with bilateral pheochromocytoma.[6] There were 5 cases in which CT showed solid tumors. Of these, the tumor was hyperdense on precontrast CT in 4 and in 1 it was isodense [Figure-1]. Following the administration of contrast there was prominent homogenous enhancement in all the 5 cases. The tumor was cystic in 17 cases and partly solid and partly cystic in 3 cases. There was homogenous enhancement of the mural nodule on contrast administration in 10 cases [Figure-2] and there was no demonstrable mural nodule even after contrast administration in 2 cases. The wall of the cyst enhanced on contrast administration in 4 cases. Tumors which were partly cystic and partly solid on CT, showed heterogeneous enhancement.

Histologically, all the tumors showed varying proportions of both types of stromal cells, thin and thick-walled blood vessels with microcysts and nuclear pleomorphism. Tumors that were solid in nature showed a large number of thin-walled capillaries and a moderate number of thick-walled vessels. Stromal cells with eosinophilic cytoplasm were in abundance and stromal cells with vacuolated cytoplasm were relatively few in number.

The reverse was true in cystic tumors where thin-walled vessels were seen in moderate numbers and thick-walled blood vessels were relatively few in number. In these cases, stromal cells with vacuolated cytoplasm were seen in abundance [Figure-3] and the numbers of cells with eosinophilic cytoplasm were relatively few [Table-1]. Microcysts were seen more frequently in patients in whom CT showed partly solid and partly cystic tumors [Figure-4]. In the cases where the CT scan showed enhancement of the cyst wall, there were thin-walled capillaries at the periphery of the tumor. In the others, the cyst wall was made up of compressed cerebellar tissue.

DISCUSSION

Hemangioblastomas most commonly occur in the cerebellum (about 86%).[1],[2],[3],[4] Hemangioblastomas may be cystic (60%) or solid (40%).[3] They may be purely cystic, purely solid, large cyst with a mural nodule or solid mass with internal cysts.[4],[7] de la Monte et al (1989) studied clinical and histopathological factors correlated with recurrence and concluded that recurrent tumors tended to be small, solid or only slightly cystic and histopathologically contained greater proportions of eosinophilic as opposed to lipid laden stromal cells.[8] In the present study, the solid tumors showed thin-walled tightly packed capillary sized blood vessels with few microcysts and they contained a large number of stromal cells with eosinophilic cytoplasm. The cystic tumors contained thick-walled blood vessels, microcysts and a larger number of lipid laden stromal cells. These findings are in agreement with earlier studies.[8]

The cyst wall generally does not enhance on contrast administration and the general agreement is that enhancement indicates neoplastic extension along the cyst wall.[9] Hemorrhage into the cyst may alter the density in the hemangioblastoma. In the present study enhancement of the cyst wall was seen in 4 cases and the solid hemangioblastomas in our series were hyperdense indicating hemorrhage into the lesion.

It is postulated that growth in solid and recurrent hemangioblastomas is due to the growth of neoplastic cells whereas in cystic and non-recurrent tumors, the increase in size is due to the enlargement of cysts.[8]

The cyst fluid contains amino acid, nitrogen, mucoprotein and alkaline phosphate levels similar to that of blood, suggesting that the cyst fluid arises by diffusion from the vascular component of the mural nodule.[10] The cyst fluid is high in protein content, accounting for its image characteristics.[4]

REFERENCES

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