Erythropoietin levels in posterior fossa haemangioblastoma

Polyglobulia in patients with hemangioblastomas is related to tumor size but not to serum erythropoietin

Background

Hemangioblastomas are associated with elevated hemoglobin (Hb) levels (polyglobulia), which is associated with a higher risk for cerebral stroke, cardiac infarction and pulmonary embolism. The pathomechanism of polyglobulia remains unclear and different theories have been postulated. Among those are elevated serum erythropoietin (EPO) levels caused by secretion of the tumor or associated tumor cyst.

Methods

To elucidate the pathomechanism, we systematically investigated the relation between polyglobulia, serum EPO level, size of the solid tumor and associated cyst in hemangioblastomas. We prospectively evaluated hemoglobin and EPO levels in a series of 33 consecutive patients operated on hemangioblastomas in our center. We measured the size of the solid tumor and associated cyst in magnetic resonance imaging. Statistical evaluations were performed using the Fisher's exact test and student's t-test.

Results

As a result five patients had elevated hemoglobin levels. Only one of these had an elevated serum EPO level. Of 26 patients with normal hemoglobin levels, 4 patients had elevated EPO levels.Patients with low or normal hemoglobin levels (84%) had an average tumor size of 0.8 cm³, which differed significantly from patients with elevated hemoglobin levels (16%), who had an average solid tumor size of 8.0 cm³ (p < 0.05). We did not observe a significant correlation between EPO levels or polyglobulia and associated cysts.

Conclusions

We therefore conclude that in contrast to previous case reports and interpretations, our data show no correlation between polyglobulia and EPO levels or associated cysts in patients with hemangioblastomas. In fact, it is the size of the solid tumor that correlates with polyglobulia.The study was retrospectively registered in the German Clinical Trial Registry on 10 July 2014; Trial registration: DRKS00006310.

Loss of Quiescence in von Hippel-Lindau Hemangioblastomas is Associated with Erythropoietin Signaling

von Hippel-Lindau (VHL) patients develop multiple central nervous system hemangioblastomas (HB). Some HBs become symptomatic with exponential growth or cyst formation following long periods of quiescence. Understanding the factors underlying growth in hemangioblastoma may lead to better strategies to arrest or prevent tumor growth. In 5 VHL patients, we resected quiescent hemangioblastomas (Q-HB) that were en-route during surgical access to symptomatic hemangioblastomas (S-HB), for matched tumor analysis. Quantitative reverse transcriptase analysis demonstrated a 2-fold increase in EPO expression in all S-HB, while 4/5 showed either Hypoxia Inducible Factor-1α or 2α upregulation. Additionally, all S-HB had increased phosphorylated erythropoietin (EPO) receptor and phosphorylated STAT-5 relative to matched Q-HB, with increased phosphorylated JAK-2 largely confined to the stromal cells in clusters within the tumors. These findings suggest that Q-HB to S-HB conversion may be associated with an erythropoietin-signaling loop. Furthermore, we found that EPO is detectable in cyst fluid from S-HB (n = 14), while absent in CSF (n = 1). Additionally, S-HB presentation or S-HB resection does not result in discernible change in serum EPO or hemoglobin (n = 60). These observations suggest that the altered erythropoietin signaling is focal and suggests that studying modulation of erythropoietin receptor pathway may lead to strategies in preventing HB growth.

Hemangioblastomas and neurogenic polyglobulia

BACKGROUND

Neurogenic polyglobulia occurs with central nervous system hemangioblastomas. Among the suggested mechanisms are extramedullary hematopoiesis in the tumor tissue and germline mutations of the von Hippel-Lindau (VHL) tumor suppressor gene.

OBJECTIVE

To determine the frequency and driving mechanisms of polyglobulia in central nervous system hemangioblastomas.

METHODS

We performed a retrospective analysis of pre- and postoperative (at 3 and 12 months) hemoglobin levels in a consecutive series of patients with hemangioblastomas operated on in our institution from 1996 to 2009. We performed molecular genetic analyses for mutations of the VHL tumor suppressor gene.

RESULTS

Preoperative hemoglobin levels were available from 164 patients. The average hemoglobin level (15.2 g/dL in males and 13.1 g/dL in females) was within normal range according to our standards. Of 22 patients with increased preoperative hemoglobin levels (>17 g/dL in males and >15 g/dL in females), 8 presented with pathological hemoglobin (>18.5 g/dL in males and >16.5 g/dL in females) according to World Health Organization criteria. Surgical removal of the hemangioblastoma resulted in a permanent cure of polyglobulia in all patients. Six of the 8 patients with pathological hemoglobin elevation carried a germline mutation of the VHL tumor suppressor gene.

CONCLUSION

Neurogenic polyglobulia occurs in a subset of patients with hemangioblastomas. This phenomenon is mostly observed in VHL mutation carriers, but also occurs in patients with sporadic hemangioblastomas. Removal of the tumor results in the permanent cure of polyglobulia. Our observations suggest that polyglobulia is an effect by the tumor itself, either due to paraneoplasia or extramedullary hematopoiesis.

Sporadic intracranial haemangioblastomas: surgical outcome in a single institution series

BACKGROUND

Haemangioblastomas are benign vascular tumours that may appear sporadically or in von Hippel-Lindau disease. Despite their higher incidence, sporadic haemangioblastomas have been less studied than syndromic ones. In this article, we evaluate the specific features, outcome and quality of life of patients with intracranial sporadic haemangioblastomas (ISHs) operated on in our institution.

METHODS

Between 1998 and 2010, 38 patients harbouring 38 ISHs were operated on in our department. Their clinical, biological, radiological and surgical features were retrospectively reviewed. All patients were contacted for a quality-of-life (QOL) survey assessed by the Short Form 36 questionnaire (SF36). The mean duration of follow-up was 40 months (13-108 months).

RESULTS

ISH represented 0.9 % of primary intracranial neoplasms treated in our centre during this period. Patients comprised 23 men and 15 women with a mean age of 47 years. None had polycythaemia. Cerebellar locations accounted for 79 % of ISHs, and brainstem ISH with involvement of the floor of the fourth ventricle represented 11 % of ISHs. At last follow-up, two patients harbouring solid medulla oblongata haemangioblastoma had died following severe bulbar syndrome and five patients had died of unrelated causes. One patient had multiple surgeries for three recurrences. Tumoral control was achieved in all cases at last follow-up. Results of the SF-36 questionnaire were as follows: median physical functioning score 100 (range 0-100), median physical problems score 100 (range 0-100), median bodily pain score 100 (range 45-100), median social functioning score 100 (range 25-100), median general mental health score 84 (range 40-92), median emotional problems score 100 (range 0-100), median vitality score 70 (range 35-80) and median general health perceptions score 70 (range 35-100). Mean QOL scores were similar to the general healthy population.

CONCLUSION

Surgery of ISH provides good QOL and tumoral control except for those located in the medulla oblongata. We recommend considering a careful multimodal therapeutic approach, including radiosurgery for these specific locations.

Surgical management of cerebellar hemangioblastomas in patients with von Hippel–Lindau disease

Object

Despite the frequency of cerebellar hemangioblastomas in von Hippel–Lindau (VHL) disease, their optimum contemporary management has not been defined, and is made complex because of the multiple, progressive, and protean nature of the tumors found in patients with this disorder. To examine modern management and outcomes of cerebellar hemangioblastomas in VHL disease, the authors reviewed findings in patients with this disease who underwent resection of cerebellar hemangioblastomas.

Methods

Consecutive patients with VHL disease who underwent surgery for cerebellar hemangioblastoma(s) at the National Institutes of Health were included. Eighty consecutive patients (44 female and 36 male patients) underwent 126 operations for removal of 164 cerebellar hemangioblastomas (age at surgery 37.8 ± 10.3 years, follow-up duration 96.0 ± 60.3 months). Serial clinical examinations, imaging studies, and operative records were analyzed.

Results

Symptoms and signs included headache (94 operations; 75%), ataxia (55%), dysmetria (29%), and hydrocephalus (28%). Although the primary objective of surgery was resection of the hemangioblastoma considered responsible for symptoms (136 of the hemangioblastomas [83%]), 28 additional hemangioblastomas (17%) were removed during the same surgeries. Tumors associated with symptoms were larger (diameter 1.8 ± 1.9 cm; volume 2.8 ± 3.4 cm3; p < 0.05) and more likely to be associated with peritumoral edema or peritumoral cysts (100% associated with edema and/or cyst; p < 0.05) than asymptomatic tumors (diameter 1.1 ± 0.9 cm; volume 0.7 ± 0.4 cm3; 18%). More tumors were located in the posterior (74%) compared with the anterior (26%) half of the cerebellum (p < 0.05). Three months after resection, symptom improvement/stabilization had occurred following 124 of the operations (98%). Preoperative hydrocephalus resolved after tumor removal in 33 cases (94%) and did not require cerebrospinal fluid diversion. Long-term imaging follow-up (61.5 ± 15.0 months) revealed no recurrences.

Conclusions

Symptoms and signs caused by cerebellar hemangioblastomas in VHL disease are associated with edema and peritumoral cyst formation/propagation and are treated safely and effectively with resection. Cerebrospinal fluid diversion is rarely necessary after complete tumor removal in patients with preoperative hydrocephalus. Cerebellar hemangioblastomas are preferentially distributed in the posterior half of the cerebellum, as they are in the brainstem and spinal cord. Tumor recurrence is avoided by meticulous extracapsular resection.

Coexpression of Erythropoietin and Vascular Endothelial Growth Factor in Nervous System Tumors Associated With von Hippel-Lindau Tumor Suppressor Gene Loss of Function

Hemangioblastomas are highly vascular tumors of the central nervous system that overexpress the hypoxia-inducible gene, vascular endothelial growth factor (VEGF), as a consequence of mutational inactivation of the von Hippel-Lindau tumor suppressor gene (VHL). Previous reports showed that hemangioblastomas can also express erythropoietin (Epo), which is also hypoxia-inducible. However, Epo expression in hemangioblastomas was observed only in individual cases, and the analyses were mainly based on indirect determination of erythropoiesis-stimulating activity. Therefore, we analyzed a series of 11 hemangioblastomas for Epo, VEGF, and VHL expression by Northern blot analysis and compared the results with normal brain and glioblastomas. Surprisingly, we observed Epo mRNA expression in all hemangioblastoma specimens analyzed, but in none of four glioblastomas. In contrast, VEGF mRNA was expressed in all hemangioblastomas and all glioblastomas. In situ hybridization revealed neoplastic stromal cells as Epo- and VEGF-producing cells in hemangioblastomas. These results suggest that in the nonhypoxic microenvironment of hemangioblastoma, Epo, similar to VEGF, might be negatively regulated by the VHL gene product.

© 1998 by The American Society of Hematology.

Coexpression of Erythropoietin and Vascular Endothelial Growth Factor in Nervous System Tumors Associated With von Hippel-Lindau Tumor Suppressor Gene Loss of Function

Hemangioblastomas are highly vascular tumors of the central nervous system that overexpress the hypoxia-inducible gene, vascular endothelial growth factor (VEGF), as a consequence of mutational inactivation of the von Hippel-Lindau tumor suppressor gene (VHL). Previous reports showed that hemangioblastomas can also express erythropoietin (Epo), which is also hypoxia-inducible. However, Epo expression in hemangioblastomas was observed only in individual cases, and the analyses were mainly based on indirect determination of erythropoiesis-stimulating activity. Therefore, we analyzed a series of 11 hemangioblastomas for Epo, VEGF, and VHL expression by Northern blot analysis and compared the results with normal brain and glioblastomas. Surprisingly, we observed Epo mRNA expression in all hemangioblastoma specimens analyzed, but in none of four glioblastomas. In contrast, VEGF mRNA was expressed in all hemangioblastomas and all glioblastomas. In situ hybridization revealed neoplastic stromal cells as Epo- and VEGF-producing cells in hemangioblastomas. These results suggest that in the nonhypoxic microenvironment of hemangioblastoma, Epo, similar to VEGF, might be negatively regulated by the VHL gene product.

© 1998 by The American Society of Hematology.

Surgical management of haemangioblastoma of the posterior fossa

Fifty-one cases of posterior fossa haemangioblastoma have been seen in our department over a period of 23 years. Seven cases were associated with spinal cord lesions and one with a supratentorial lesion. There were 22 cases of Lindau's disease (43%). The onset was earlier and recurrences commoner than in isolated cases. In 10 cases the development of new tumours in different parts of the central nervous system (CNS) required re-operation, demonstrating the multicentric nature of this disease. The majority of the tumours occupying the fourth ventricle or medulla oblongata (8 cases) were macroscopically solid and had higher post-operative morbidity than the cystic tumours in the cerebellum. The recent development of magnetic resonance imaging (MRI) provides accurate anatomical information of the lesions (especially those of the brain stem and spinal cord) even while asymptomatic. The brilliant enhancement of these tumours on MRI with Gadolinium-diethyline-triamine-pentaacetic acid (Gd-DTPA) has proved to be particularly useful.

Erythropoietin in capillary hemangioblastoma. An immunohistochemical study

Capillary hemangioblastoma is a tumor known to be associated with secondary polycythemia. Therefore, specimens from ten hemangioblastomas were studied by immunohistochemistry for the presence of erythropoietin, renin substrate, and for various endothelial, histiocytic and glial markers. In all tumors scattered cells among the stromal cells showed a positive-staining reaction with both anti-erythropoietin and anti-renin substrate. The same cells also stained positively for alpha-1-anti-trypsin. It is concluded that, in addition to the capillary endothelial cells, pericytes and stromal cells, capillary hemangioblastomas harbor cells containing and perhaps producing renin substrate and/or erythropoietin or a substance with similar antigenic determinants.

Cerebellar hemangioblastoma with erythropoietin in cerebrospinal fluid

A patient with cerebellar hemangioblastoma and secondary erythrocytosis is presented. Erythropoietin, indirectly determined by measuring 59Fe incorporation in polycythemic mouse bioassay, was not detected in serum and urine, but was found in cerebrospinal fluid. The significance of erythropoietin determination in cerebrospinal fluid in patients with cerebellar hemangioblastoma is stressed.

Histogenesis of haemangioblastomas: an immunocytochemical and ultrastructural study in a case of von Hippel-Lindau syndrome

The cerebellar, retinal, and one of the spinal haemangioblastomas in a case of von Hippel-Lindau syndrome were studied by immunocytochemistry and electron microscopy. The tumours were positive for neurone specific enolase and variably positive for somatostatin, pancreatic polypeptide, and bombesin. Electron microscopy of the cerebellar tumour showed secretory granules with an average diameter of 170 nm. This report is believed to be the first description of neurone specific enolase positivity and polypeptide hormones within the intervascular cells of haemangioblastomas. In the light of these findings it is suggested that haemangioblastomas are tumours of neuroectodermal origin, derived either from neural or neuroendocrine cells.

Haemangioblastomas of the posterior cranial fossa

The clinical features, diagnostic and surgical aspects of haemangioblastoma of the posterior cranial fossa are discussed in the light of a series of 61 personal cases and the published data. CT and vertebral angiography are compared as diagnostic tools. With the aid of microsurgery even haemangioblastomas of the brainstem and fourth ventricle can be removed successfully.