Clinical and molecular analysis of disseminated hemangioblastomatosis of the central nervous system in patients without von Hippel-Lindau disease. Report of four cases

Case report: Hemangioblastoma in the brainstem of a dog

A 3-year-old castrated male, American Pit Bull Terrier presented to Texas A&M University due to a 3-week mixed cerebellar and general proprioceptive ataxia, circling, head tilt, and dull mentation. Neurologic examination revealed signs of vestibular and mesencephalic dysfunction. Postmortem examination revealed a 1.1 × 1 × 0.8-cm, soft, dark red, well-circumscribed, left-sided mass, extending from the crus cerebri of the midbrain caudally to the pons. Microscopically, the neoplasm was composed of a spindle-shaped interstitial population of cells interspersed between a prominent capillary network, consistent with the reticular pattern of hemangioblastoma. Interstitial cells had strong, diffuse, intracytoplasmic immunolabeling for neuron-specific enolase (NSE) and were variably positive for intracytoplasmic glial fibrillary acidic protein (GFAP). Vascular endothelial cells had strong diffuse, intracytoplasmic immunolabeling for von Willebrand factor (VWF) glycoprotein. To date, only six cases of hemangioblastoma have been reported in canines, five in the spinal cord, and one in the rostral cerebrum. Our case may represent the first canine hemangioblastoma localized to the brainstem.

Spinal leptomeningeal hemangioblastomatosis occurring without craniospinal surgery in von Hippel-Lindau disease

Hemangioblastomatosis represents an unusual and malignant leptomeningeal dissemination of hemangioblastoma (HB). It has been reported in patients with sporadic HB or von Hippel-Lindau (VHL) disease. Hemangioblastomatosis had been reported following resection of a primary HB lesion in all cases except one patient with a sporadic HB. We present a patient with VHL with several HBs at the brainstem, cerebellum, pituitary stalk and retina who developed spinal hemangioblastomatosis without previous craniospinal surgery. A whole spine MRI showed the spinal dissemination from the primary lesions. The patient received craniospinal radiotherapy due to the extensive spinal leptomeningeal dissemination and multiple HBs. MRI performed 12 months after the radiotherapy showed stability of the lesions.

Aggressive dissemination of central nervous system hemangioblastoma without association with von Hippel–Lindau disease: A case report and literature review

Background:

Hemangioblastomas (HBs) typically present with benign behavior and are most commonly found in the posterior fossa. Multiple central nervous system (CNS) HBs are usually associated with von Hippel–Lindau disease, and leptomeningeal dissemination of sporadic HBs is extremely rare. A review of the literature identified 30 cases of leptomeningeal dissemination of sporadic HBs previously published in the literature.

Case Description:

We report the case of a patient who was diagnosed with multiple CNS HBs with aggressive progression 6 years after resection of a posterior fossa HB. He underwent multiple surgeries and died 4 years after the diagnosis of the first spinal dissemination.

Conclusion:

Dissemination of sporadic HBs is rare and aggressive disease evolution is usually observed. Further studies are necessary to determine the optimal therapeutic options.

Masked malignant phenotype with a benign appearance: beat-up copy number profile may be the key for hemangioblastoma dissemination

Dissemination of histologically benign hemangioblastoma is rare; approximately 30 cases have previously been reported, and all cases occurred several months to years after surgical resection. Herein, we report a case of hemangioblastoma in which leptomeningeal dissemination occurred 2 years after hypofractionated radiation therapy (39 Gy/13 fractions). The tumor was treated primarily with radiation without surgical resection. Biopsy of the disseminated lesion confirmed histological diagnosis as histologically benign hemangioblastoma. Ki67 index was not remarkably elevated for hemangioblastomas. In addition, the methylation class determined by the methylation profiling classifier developed by the German Cancer Research Center (DKFZ)/University Hospital Heidelberg/German Consortium for Translational Cancer Research was consistent with that of common hemangioblastomas. However, genetic analyses showed significant gains and losses throughout the whole genome, indicating that highly aberrant copy number profiles may be the key to elucidating this rare but life-threatening clinical entity. Accumulation of more detailed case reports based on the comparison of specimens obtained before and after surgery or radiation is necessary to better understand the pathophysiology of the dissemination phenotype of hemangioblastoma.

Disseminated central nervous system hemangioblastoma in a patient with no clinical or genetic evidence of von Hippel-Lindau disease-a case report and literature review

BACKGROUND

Hemangioblastomas (HB) are benign tumors of the central nervous system (CNS) that can appear sporadic or as part of von Hippel-Lindau (VHL) disease. It is often curable with surgical resection, but upon relapse, the disease exhibits a treatment-refractory course.

CASE REPORT

A patient treated for sporadic cerebellar HB relapsed 12 years post-surgery. She developed disseminated disease throughout the CNS, including leptomeningeal manifestations. Repeat surgery and craniospinal radiation therapy were unsuccessful.

CONCLUSION

This case is in line with previous publications on disseminated non-VHL HB. Available treatment options are inefficient, emphasizing the need for improved understanding of HB biology to identify therapeutic targets.

Differences in genetic and epigenetic alterations between von Hippel-Lindau disease-related and sporadic hemangioblastomas of the central nervous system

Background

Although inactivation of the von Hippel-Lindau gene (VHL), located on chromosome 3p25, is considered to be a major cause of hemangioblastomas (HBs), the incidence of biallelic inactivation of VHL is reportedly low. The aim of this study was to determine the prevalence of VHL alterations in HBs, as well as to identify additional molecular aberrations.

Methods

Genetic and epigenetic alterations were comprehensively and comparatively analyzed in 11 VHL-related and 21 sporadic HBs.

Results

VHL alterations detected by sequencing and multiplex ligation-dependent probe amplification (MLPA) analysis were more frequent in VHL-related HBs than in sporadic HBs (100% vs 62%; P = 0.029). VHL alterations were found only in 4 sporadic HBs by direct sequencing; however, targeted deep sequencing detected 9 additional alterations. Loss of heterozygosity (LOH) on chromosome 3 was found in 64% and 57% of VHL-related and sporadic HBs, respectively, by single nucleotide polymorphism (SNP) array analysis. Among 19 tumors with chromosome 3 LOH, 5 were classified as copy-neutral LOH. VHL promoter hypermethylation was detected only in sporadic HBs (33%), indicating that epigenetic suppression of VHL is a common mechanism in sporadic HBs. The rate of biallelic VHL inactivation among VHL-related and sporadic HBs was 64% and 52%, respectively. LOH on either chromosome 6 or 10 was detected only in sporadic HBs (43%).

Conclusion

Although biallelic inactivation of VHL is a dominant mechanistic cause of the pathogenesis of HB, other unknown mechanisms may also be involved, and such mechanisms may be different between VHL-related and sporadic HB.

Pedigree analysis, diagnosis and treatment in Von Hippel-Lindau syndrome: A report of three cases

The objective of the present study was to systematically investigate the clinical features, diagnosis and therapeutic treatment of Von Hippel-Lindau (VHL) syndrome in order to improve understanding of this disease. A total of 3 cases of VHL syndrome treated at the Affiliated Hospital of Zunyi Medical College (Zunyi, China) between September 2014 and October 2015 were retrospectively analyzed. The associated literature was reviewed, and the diagnostic and therapeutic features were discussed. Case 1 was diagnosed as VHL syndrome accompanied by a renal tumor on the right side, and radical tumor resection in the right kidney was performed. Postoperative pathological examination indicated clear cell carcinoma. Case 2 was diagnosed as VHL syndrome accompanied by bilateral adrenal pheochromocytoma. The left-side adrenal tumor was removed, and postoperative pathological analysis was suggestive of adrenal pheochromocytoma. Case 3 visited the hospital due to the presence of masses on the left and right sides of the kidney, but did not undergo surgery for personal reasons. Follow-ups were scheduled subsequent to surgery at another hospital. The diagnosis in all 3 cases was confirmed by genetic testing, where VHL mutations were detected in all patients. Following surgery, pedigree and genetic analysis was performed in all 3 pedigrees and VHL mutations were identified in 7 family members. The diagnosis of VHL syndrome should be based on the clinical manifestation of the patients and the results of genetic tests. DNA analysis of mutations is the main method for diagnosis. An appropriate surgical plan should be formulated based on the site, size and number of tumors, and the condition of the patient. Since VHL syndrome is an inheritable genetic disorder and relapse following surgery is common, pedigree analysis of the patient and lifelong follow-ups are essential. Additionally, physicians should pay attention to VHL syndrome in order to avoid missing diagnosis or misdiagnosis.

CNS hemangioblastomatosis in a patient without von Hippel-Lindau disease

We report on a case of disseminated CNS hemangioblastoma, also referred to as hemangioblastomatosis, involving the supratentorial compartment and the entire spine. The patient presented with new onset headache, gait difficulties and memory deficits many years following resection of a hemangioblastoma from the cerebellum. The patient's family history was negative for von Hippel-Lindau (VHL) disease, and his personal history was negative for any additional VHL-defining lesions. Imaging revealed extensive dural caking and nodularity both supratentorially and in the spine, along with scattered parenchymal tumors showing a more typical appearance for hemangioblastoma. Biopsy of the dural thickening revealed histologic features compatible with hemangioblastoma. Genetic testing for VHL was eventually completed, and no evidence of a germline VHL mutation was detected.

Vascular hyperpermeability as a hallmark of phacomatoses: is the etiology angiogenesis comparable with mechanisms seen in inflammatory pathways? Part I: historical observations and clinical perspectives on the etiology of increased CSF protein levels, CSF clotting, and communicating hydrocephalus: a comprehensive review

Phacomatoses are a special group of familial hamartomatous syndromes with unique neuro-cutaneous manifestations as well as disease characteristic tumors. Neurofibromatosis 2 (NF2) and tuberous sclerosis complex (TSC) are representatives of this family. Vestibular schwannoma (VS) and subependymal giant cell tumor (SGCT) are two of the most common intracranial tumors associated with NF2 and TSC, respectively. These tumors can present with obstructive hydrocephalus due to their location adjacent to or in the ventricles. However, both tumors are also known to have a unique association with an elevated protein concentration in the cerebrospinal fluid (CSF), sometimes in association with non-obstructive (communicating) hydrocephalus (HCP), the causality of which has been unclear. Furthermore, SGCTs have repeatedly been shown to have a predisposition for CSF clotting, causing debilitating obstructions and recurrent malfunctions in shunted patients. However, the exact relation between high protein levels and spontaneous clotting of the CSF is not clear, nor is the mechanism understood by which CSF may clot in SGCTs. Elevated protein levels in the CSF are thought to be caused by increased vascular permeability and dysregulation of the blood-brain barrier. The two presumed underlying pathophysiologic mechanisms for that, in the context of tumorigenesis, are angiogenesis and inflammation. Both mechanisms are correlated to the Pi3K/Akt/mTOR pathway which is a major tumorigenesis pathway in nearly all phacomatoses. In this review, we discuss the influence of angiogenesis and inflammation on vascular permeability in VSs and SGCTs at the phenotypic level as well as their possible genetic and molecular determinants. Part I describes the historical perspectives and clinical aspects of the relationship between vascular permeability, abnormal CSF protein levels, clotting of the CSF, and communicating HCP. Part II describes different cellular and molecular pathways involved in angiogenesis and inflammation in these two tumors and the correlation between inflammation and coagulation. Interestingly, while increased angiogenesis can be observed in both VS and SGCT, inflammatory processes seem more prominent in SGCT. Both pathologies are characterized by different subgroups of tumor-associated macrophages (TAM): the pro-inflammatory, M1 type is predominating in SGCTs while pro-angiogenetic, M2 type is predominating in VSs. We suggest that lack of NF2 protein in VS and lack of TSC1/2 proteins in SGCT determine this fundamental difference between the two tumor types, by defining the predominant TAM type. Since inflammatory reactions and coagulation processes are tightly connected, a "pro-inflammatory state" of SGCT can be used to explain the observed associated enhanced CSF clotting process. These distinct cellular and molecular differences may have direct therapeutic implications on tumors that are unique to certain phacomatoses or those with similar genetics.

Hemangioblastomas with leptomeningeal dissemination: case series and review of the literature

BACKGROUND

Leptomeningeal dissemination of hemangioblastomas (HB) of the central nervous system (CNS) is extremely rare. Few studies have reported leptomeningeal involvement in sporadic HB or in HB associated with von Hippel-Lindau syndrome. The clinical and radiological features of leptomeningeal involvement in HB after surgery have not been described in detail.

MATERIALS AND METHODS

This retrospective case review involved patients from three different tertiary referral centers with leptomeningeal dissemination of HB after surgery for the primary mass. A literature review was also performed to describe the clinical and radiological characteristics and long-term outcomes of patients who developed leptomeningeal dissemination after initial surgical resection.

RESULTS

This study included seven patients, five males and two females, ranging in age from 36 to 54 years. Incidence of leptomeningeal dissemination in patients with HB was about 4.3 % (3/69). It appeared at a mean 94.9 months (range, 39-204 months) after gross total resection of CNS HBs. Three of the seven patients died 5, 38, and 79 months, respectively, after diagnosis of leptomeningeal dissemination. Review of the literature identified 21 patients with characteristics of leptomeningeal dissemination similar to those in our series.

CONCLUSIONS

Leptomeningeal dissemination of HB is a rare pattern of long-term recurrence. Long-term outcomes may be fatal. The long developmental period suggests that early detection and aggressive management may improve prognosis in patients with CNS leptomeningeal dissemination of HB.

Hemangioblastoma in the lung: metastatic or primary lesions?

Hemangioblastoma primarily occurs in the CNS, most commonly in the posterior fossa. Extracranial locations are less common, and metastatic tumor involving the lung is exceedingly rare with only three cases previously reported. Two were autopsy studies in patients who died of complications of the CNS hemangioblastomas in 1943 and 1981, and the third was mentioned in a case report addendum providing follow-up information on hepatic hemangioblastoma in 1991. We report a case of a 48-year-old man who presented with multiple lung nodules treated by surgical excision. Pathological study revealed features classic for hemangioblastoma. The patient had a remote history of hemangioblastomas having been excised from the posterior fossa 7 and 20 years previously. This report details a fourth case of metastatic pulmonary hemangioblastoma. It is the first report on surgically resected hemangioblastomas from the lung of a living patient with histological and immunohistochemical characterization.

Disseminated Hemangioblastoma of the Central Nervous System without Von Hippel-Lindau Disease

Hemangioblastoma (HB) of the central nervous system may occur sporadically or in association with von Hippel-Lindau (VHL) disease. Disseminated HB means malignant spread of the original primary HB without local recurrence at surgically resected site. It has been rarely reported previously, and rarer especially without VHL gene mutation. We report a case of disseminated HB without VHL disease. A 59-year-old man underwent a surgery for total removal of a cerebellar HB. From five years after the surgery, multiple dissemination of HB was identified intracranially and he subsequently underwent cyberknife radiosurgery. The lesions got smaller temporarily, but they soon grew larger. Nine years after the initial surgery for cerebellar HB, he showed severe back pain. His magnetic resonance image of spine revealed intradural extramedullary mass at T6-7 level. Complete surgical removal of the mass was performed and the pathological diagnosis was identical to the previous one. He had no evidence of VHL disease. And there was no recurrence of the tumor at the site of the original operation. The exact mechanism of dissemination is unknown, but the surgeon should be cautious of tumor cell spillage during surgery and prudently consider the decision to perform ventriculo-peritoneal shunt. In addition, continuous follow-up for recurrence or dissemination is necessary for patients even who underwent complete removal of cerebellar HB.

Disseminated cerebellar hemangioblastoma in two patients without von Hippel-Lindau disease

BACKGROUND

Two patients who had received a total resection of cerebellar hemangioblastoma developed cerebrospinal fluid dissemination during a long-term follow-up period. We present this rare disease with discussion based on the literature.

CASE DESCRIPTION

The patients were two women aged 45 and 57 years. In the cerebellar hemisphere, one patient had cystic hemangioblastoma of mural nodule type and the other had solid type. Both the patients successfully underwent total resection by craniotomy. They presented no mutations in the von Hippel-Lindau disease (VHL) gene or lesions in the other organs. One patient developed local recurrence 38 months after the initial surgery, and received stereotactic radiosurgery. Three spinal cord tumors developed 91 months later, and the tumors were disseminated to the entire cerebrospinal cavity 107 months later. The other patient developed hydrocephalus 53 months after the initial surgery with tumor tissues disseminated in the intracranial subarachnoid space. The conditions of the two patients gradually aggravated despite treatment with ventriculo-peritoneal shunt and irradiation to the whole brain and whole spinal cord.

CONCLUSION

Cerebrospinal fluid dissemination of cerebellar hemangioblastoma was found dominantly in non-VHL patients. The diagnosis was made 10 years after the initial surgery. Irradiation therapy was performed, but the patients died about 2 years after the diagnosis was given. Molecular targeted therapies including vascular proliferation suppression have been attempted lately, but no effective therapy has been established. Early diagnosis of dissemination as well as combination of aggressive excision and stereotactic radiosurgery are considered to be appropriate for current interventions.

Man with posterior fossa tumors 15 years apart

A 48-year-old man with a history of hypertension, peripheral vascular disease and a 50-pack-year history of smoking presented with new onset vertigo, tinnitus, diplopia and ataxia in January 1978. CT scan showed a radiolucent defect in the left cerebellar hemisphere with a possible mural nodule. In ensuing months, he experienced worsening symptoms with a corresponding increase in lesion size on re-imaging. Months later, a left posterior fossa craniotomy was performed and revealed a single cystic lesion containing copious amounts of straw-colored fluid and a single mural nodule in the inferior portion of the cyst. Following resection, he was followed clinically until 1985 at which time follow-up was discontinued. He did well until January 1993 when he presented with progressively worsening episodic headaches and retro-orbital pressure. Subsequent MRIs of the brain and spine (February 1993, March 1993) showed multiple lesions along the neuraxis involving the superficial brain parenchyma, leptomeninges, and dura. Despite therapy, his condition progressively declined until he succumbed. A brain-only autopsy revealed numerous small tumor nodules involving the base of the brain over both frontal and temporal lobes, midbrain, pons, right optic nerve, pituitary fossa, and the base of the skull. Pathologic evaluation revealed metastatic hemangioblastoma. Metastatic hemangioblastoma is a rare entity, with only a few reported cases in the literature to date.

Cerebellar haemangioblastoma: a rare entity

A 45-year-old female presented with headache, nausea, vomiting and ataxia of 4-month duration. CT head showed a posterior fossa tumour which was diagnosed as a case of haemangioblastoma on microscopic examination.

Endolymphatic sac tumor (aggressive papillary tumor of middle ear and temporal bone): sine qua non radiology-pathology and the University of Texas MD Anderson Cancer Center experience

Endolymphatic sac tumor (ELST) is a rare lesion of the skull base for which the origin has recently been ascertained. The endolymphatic sac is derived from neuroectoderm and is located subjacent to the posteromedial surface of the temporal bone. Patients characteristically present with hearing loss, tinnitus, and vertigo; facial nerve paralysis occurs less commonly. An indolent clinical course and long-standing symptom history is typical. Endolymphatic sac tumors are known to occur more frequently in patients with von Hippel-Lindau disease, but this is not a prerequisite for diagnosis because sporadic occurrence is common. Morphologically, all of the ELSTs showed a papillary and glandular architecture. The papillary and glandular structures were lined by a single layer of flattened cuboidal-to-columnar cells that were variably ciliated. Surgery is the treatment of choice for small ELST. Remission may last for years, but local recurrence after surgery, likely secondary to incomplete resection, can occur. Radiotherapy has a 50% cure rate with large or residual tumors. Endolymphatic sac tumor is a rare tumor that can easily be confused with other papillary lesions on histopathologic grounds, with significant treatment implications. Precise preoperative anatomic localization and computed tomography and magnetic resonance imaging feature interpretation play a paramount role in achieving an accurate final diagnosis.

Von Hippel-Lindau disease manifesting disseminated leptomeningeal hemangioblastomatosis: surgery or medication?

We report the case of a 46-year-old man with von Hippel-Lindau (VHL) disease, manifesting disseminated leptomeningeal hemangioblastomatosis. The patient initially presented with a solitary hemangioblastoma in the right cerebellum. Later, he was diagnosed with VHL disease and underwent several surgical procedures in the following 14 years. But the prognosis was poor. Recently, the hemangioblastomatosis disseminated along leptomeninges involving both brain and spine. We aim to analyze the possible reason for the leptomeninges dissemination, discuss the imaging characteristics of this rare disease with ominous manifestation and propose the optimal strategy for treatment. We think the optimal treatment strategy should be surgical biopsy and surgical decompression. A long-term follow-up is inevitable. Antiangiogenic medication might be the hope for remission of this disease.

Non-von Hippel-Lindau Hemangioblastoma in the Hippocampus: Characterization with Time-Resolved MRA Using TRICKS Sequence at 3T. A Case Report

Supratentorial hemangioblastomas (HBs) are exceedingly rare tumors accounting for 5%-10% of all HBs and usually present in the setting of von Hippel-Lindau (VHL) disease. Isolated HBs of the central nervous system also occur as a result of spontaneous mutation in the absence of any clinical manifestations of VHL disease. Of 13 temporal lobe HBs, only one non-VHL case was reported in the hippocampus. We describe the TRICKS findings in a case of isolated hemangioblastoma in the hippocampus without VHL disease. To our knowledge, this is the second case report of a hippocampal non-VHL hemangioblastoma.

Low frequency of VHL germline mutations in Norwegian patients presenting with isolated central nervous system hemangioblastomas--a population-based study

OBJECTIVES

Explore the genetic and clinical incidence of von Hippel-Lindau disease in patients presenting with isolated central nervous system hemangioblastomas.

RESULTS

We report a 3.2% (1/31) and 25% (8/32) incidence of genetic and clinical VHL, respectively. One patient tested positive for a VHL mutation that has not previously been reported. This genotype phenotypically predicts VHL type 2B. We had seven patients with renal cysts. In a total follow-up of 33 person years, none of these cysts progressed to renal cell carcinoma.

CONCLUSION

von Hippel-Lindau disease anchored in germline mutations of the VHL gene is rare in the Norwegian population as opposed to clinical VHL disease, which appears to be relatively common in patients with apparently sporadic hemangioblastomas. There exists insufficient data regarding the natural history of patients with renal cysts, which makes it difficult to include or disregard these lesions as an entity of VHL disease.

Disseminated hemangioblastomatosis of the central nervous system without von Hippel-Lindau disease: a case report

We report a very rare case of hemangioblastomatosis that developed after surgical removal of a solitary cerebellar hemangioblastoma (HB). A 51-yr-old man presented with back pain 10 yr after undergoing surgery for cerebellar HB. Magnetic resonance imaging showed numerous mass lesions along the entire neuraxis accompanied by prominent leptomeningeal enhancement. Genomic DNA analysis showed no mutation in the von Hippel-Lindau (VHL) genes. A surgical specimen obtained from a lesion in the cauda equina showed pathological findings identical to those of the cerebellar HB that had been resected 10 yr earlier. External beam radiation therapy and radiosurgery were subsequently performed; however, the patient succumbed one year after receiving the diagnosis of hemangioblastomatosis. The reduction of tumor cell spillage during surgery and regular long-term follow-up are recommended for patients with HBs.

Intradural extramedullary leptomeningeal hemangioblastomatosis and paraneoplastic limbic encephalitis diagnosed at autopsy: an unlikely pair

Typical cerebellar or spinal cord hemangioblastoma is often solitary and has a benign clinical course, whereas disseminated hemangioblastomatosis is extremely rare. We report a 75-year-old man with disseminated "leptomeningeal" hemangioblastomatosis and concurrent paraneoplastic limbic encephalitis who died of this disease. The patient presented with gait problems and cognitive deficits, and was diagnosed with a cervical spinal tumor. Surgical resection achieved an apparent gross total resection, but later the patient began experiencing severe cognitive decline. His condition progressively deteriorated during the next few months, and he died 15 months after his initial surgery. Autopsy revealed disseminated extramedullary intradural hemangioblastomatosis with extensive leptomeningeal nodules involving the entire spinal cord, medulla, pons, and midbrain, as well as histologic features of limbic encephalitis. There was no evidence of von Hippel-Lindau disease, and no specific etiology was identified for the dementia. To the best of our knowledge, this is the first case of limbic encephalitis occurring in the setting of disseminated hemangioblastomatosis.

Disseminated haemangioblastoma without evidence of the von Hippel-Lindau syndrome or haemangioblastomatosis--A case report and clinico-pathological correlation

A 71-year-old Caucasian female presented to our service with disseminated cranial and spinal haemangioblastomata but no other features to suggest the von Hippel-Lindau syndrome. We feel that this represents cellular dissemination through the cerebro-spinal fluid and may be an intermediate step to the development of frank haemangioblastomatosis. By comparing this presentation to that of other tumours we have suggested a potential pathological mechanism and have discussed its management.

Clear cell type of renal cell carcinoma with numerous hyaline globules: a diagnostic pitfall

A unique and never-before-published example of clear cell renal cell carcinoma (CRCC) found among 9000 primary renal cell tumors is presented. The tumor contained such a dense concentration of glassy hyaline globules (GHG) in the cytoplasm of the neoplastic cells that it overshadowed the morphology of the neoplasm. The resulting appearance of the tumor was quite misleading and different from the conventional CRCC. The GHG were 7-30 microm in diameter. They were glassy and pale to slightly eosinophilic in color in hematoxylin-eosin. The GHG stained positively with periodic acid-Schiff and negatively with silver and Hale's colloidal iron. Immunohistochemically, they were also negative for anti Mycobacterium bovis antigen. At the ultrastructural level, the GHG were formed by an amorphous mass of stellate shape. The GHG were localized within rough endoplasmic reticulum. Molecular genetically, mutation of the distal part of exon 3 of the VHL gene causing elongation of the VHL protein was found in the tumor, thus confirming the diagnosis of CRCC.

Hemangioblastomatosis of the central nervous system without von Hippel–Lindau Disease: a case report

We report a very rare case of hemangioblastomatosis in a patient without von Hippel-Lindau disease (VHL). A 50-year-old woman had a history of surgical procedures for total removal of a cerebellar hemangioblastoma (HB). Twenty-one years after the last operation, she developed communicating hydrocephalus; computed tomographic (CT) scans of the brain showed no recurrence of HB in the posterior fossa. Subsequently, she underwent placement of a ventriculo-peritoneal shunt. One year later, she was readmitted because of progressive numbness and pain in the left lower limb. Magnetic resonance imaging (MRI) showed multiple Gd-enhancing tumors around the brain stem, in the cerebellum, and in the cervical and thoracolumbar regions of the spine. She underwent surgical removal of the tumors in the cerebellum and spinal cord. Although the extirpated tissues were histopathologically verified HB with less than 1% MIB-1 labeling index, surgery was followed by external beam radiation therapy with doses of 40 Gy to the whole brain, 10 Gy to the posterior fossa and 30 Gy to the whole spine. However, she subsequently developed quadriparesis and became bedridden.

Hemangioblastoma of the lateral ventricle: case report and review of the literature

We report a unique case of hemangioblastoma of the lateral ventricle in a 73 year-old man with cognitive deficits and fluent dysphasia. He harboured an intraventricular tumor, placed at the trigone of the left lateral ventricle. The tumor was successfully excised, by means of a temporal craniotomy. The patient became mute in the immediate postoperative with restoration of speech within a few days. The literature has been reviewed and only three other similar cases have been reported. Discovery of lesions in such unusual location should raise a high degree of suspicion for von Hippel-Lindau disease.

Primary capillary hemangioblastoma of peripheral soft tissues

A case of capillary hemangioblastoma located in the peripheral soft tissue of the inner ankle in a 74-year-old woman is presented. The tumor was an unencapsulated but sharply circumscribed nodule 2.5 cm in size, of a yellow-white color. It showed reddish-brown spots with small cysts up to 2 mm filled with blood. Grossly the tumor was not attached to any peripheral nerve. Signs of von Hippel-Lindau's disease were excluded by thorough clinical evaluation. No additional tumor or erythrocytosis was found in the patient clinically. Immunohistochemically, the tumor stromal cell reacted strongly with antibodies to S-100 protein, NSE, and calponin and they were negative with antibodies to GFAP, CD34, CD31, cytokeratins, actin, desmin, EMA, and HMB-45. Endothelium of the capillaries reacted positively with antibodies to CD31, CD34, and Factor VIII-related protein. Capillary pericytes were actin-positive. All cells of the tumor stained positively with antibody to vimentin. MIB1 antibody reacted only in very few cells (<1%). Ultrastructurally, the stromal cells contained electron-lucent cytoplasm with lipid droplets, a small amount of rough endoplasmic reticulum, and glycogen particles. No electron-dense structures typical of secretory granules were seen in the stromal cells. No mutation of coding sequence of VHL gene was found.

Long-term prognosis of hemangioblastomas of the central nervous system: Clinical and immunohistochemical study in relation to recurrence

The long-term prognosis and immunohistochemical findings for the expression of VEGF (vascular endothelial growth factor), p53 protein, and proliferative potential with MIB-1 were evaluated in six patients with VHL (von Hippel-Lindau) disease and seven patients with sporadic hemangioblastomas in relation to recurrent or new central nervous system (CNS) hemangioblastomas following treatment. Sporadic CNS hemangioblastomas were treated by total removal, and they demonstrated a good long-term prognosis without neurological deficits and no recurrence. However, even if total removal of the CNS hemangioblastomas in patients with VHL disease was performed initially, new lesions, consisting of small multiple hemangioblastomas, recurred in areas remote from the primary region in three of four patients during long-term follow-up. Such newly developed hemangioblastomas in patients with VHL disease could reflect the biological multipotentiality of CNS hemangioblastomas that were not detected during the initial operation. All of the hemangioblastomas displayed extensive overexpression of VEGF protein. The immunohistochemical findings for VEGF protein, p53 protein, and MIB-1 did not differ significantly between the sporadic and VHL disease-associated hemangioblastomas. In conclusion, since patients with VHL disease are at risk of developing new lesions, the management of hemangioblastomas in patients with VHL disease represents a more prolonged and difficult task.

Endolymphatic sac tumors in patients with and without von Hippel-Lindau disease: the role of genetic mutation, von Hippel-Lindau protein, and hypoxia inducible factor-1alpha expression

OBJECT

Endolymphatic sac (ELS) tumors are low-grade malignancies of the temporal bone that are associated with von Hippel-Lindau (VHL) disease but can also occur sporadically. The VHL gene product VHL protein is important in the regulation of hypoxia inducible factor (HIF)-1alpha, which controls expression of molecules that are important in angiogenesis and cell metabolism. In this study the authors examine the role of VHL and HIF-1 in ELS tumors.

METHODS

The ELS tumors from three patients were examined using the following method: DNA from tumor tissue was isolated, amplified by polymerase chain reaction and the VHL gene sequence was compared with the known wild-type sequence. Loss of heterozygosity (LOH) studies were performed to confirm the sequencing data. Immunohistochemical evaluation for VHL, HIF-1alpha, vascular endothelial growth factor (VEGF), and carbonic anhydrase IX (CA IX) was performed. Snap-frozen tumor tissue was examined using Western blot and HIF-1 immunoassays for HIF-1alpha and VHL expression. Two patients had sporadic ELS tumors and the other one suffered from VHL disease. Results of VHL gene sequencing were normal in the tissue derived from the sporadic ELS tumors. The ELS tumor, pheochromocytoma, and spinal hemangioblastoma were heterozygous for the same C-to-A transversion found in the germline carried by the patient with VHL disease. No LOH was detected in the tumor tissue obtained in the patient with VHL disease. Expression of HIF-1alpha, VEGF, and CA IX evaluated using immunohistochemical studies was elevated in the VHL-associated tumors. Nevertheless, Western blots and immunoassays for HIF-1alpha did not show elevated expression in these tumors.

CONCLUSIONS

The sporadic and VHL disease-associated ELS tumors in this study had normal VHL-mediated HIF-1 regulation. This is a result of normal VHL gene expression in the case of the sporadic ELS tumor. In the VHL-associated ELS tumor, this is due to one normal copy of the VHL gene and adequate VHL gene expression.