Deafness due to bilateral endolymphatic sac tumours in a case of von Hippel-Lindau syndrome

Bilateral internal auditory canal gangliogliomas mimicking neurofibromatosis Type II

Background:

Gangliogliomas are rare low grade, typically well-differentiated, tumors that are composed of mature ganglion cells and neoplastic glial cells. These tumors can appear at virtually any location along the neuroaxis but classically occur in the temporal lobe of young patients. In a small number of cases, gangliogliomas have presented as masses in the brainstem or involving cranial nerves. With the exception of vestibular schwannomas, bilateral tumors in the region of the internal auditory canal (IAC) or cerebellopontine angle (CPA) are exceedingly rare.

Case Description:

We report a case of a 58-year-old male who presented with hearing loss, tinnitus, and vertigo. Initial magnetic resonance imaging revealed bilateral nonenhancing IAC/CPA tumors. Based on this finding, a presumptive diagnosis of neurofibromatosis Type II was made, which was initially managed conservatively with close observation. He returned for follow-up with worsening vertigo and tinnitus, thus prompting the decision to proceed with surgical resection of the symptomatic mass. Intriguingly, pathological study demonstrated a WHO Grade I ganglioglioma.

Description:

We report a case of a 58-year-old male who presented with hearing loss, tinnitus, and vertigo. Initial magnetic resonance imaging revealed bilateral nonenhancing IAC/CPA tumors. Based on this finding, a presumptive diagnosis of neurofibromatosis Type II was made, which was initially managed conservatively with close observation. He returned for follow-up with worsening vertigo and tinnitus, thus prompting the decision to proceed with surgical resection of the symptomatic mass. Intriguingly, pathological study demonstrated a WHO Grade I ganglioglioma.

Conclusion:

This is the first reported case of bilateral IAC/CPA gangliogliomas. When evaluating bilateral IAC/CPA lesions with unusual imaging characteristics, ganglioglioma should be included in the differential diagnosis.

[Epidemiology, treatment and follow-up of central nervous system hemangioblastomas in von Hippel-Lindau disease]

INTRODUCTION

Central nervous system (CNS) hemangioblastomas (HGB) are rare vascular tumors. The goal of this study was to analyze their epidemiology, treatment and prognosis in association with von Hippel-Lindau (VHL) disease.

METHODS

We retrospectively reviewed a series of patients treated in our department for a CNS HGB with VHL disease between 1996 and 2008. We analyzed pre- and postoperative clinical and radiological characteristics, number of visceral lesions (fundoscopy, abdomino-pelvian CT, metanephrines), clinical course (modified Rankin Scale and McCormick scale) and late prognosis (Kaplan-Meier survival curves).

RESULTS

We studied 19 cases (sex-ratio 0.9, mean age 36). The mean time to diagnosis was 61days. The main symptom was intracranial hypertension for cerebellar lesions (7/15) and a sensitive-motor deficit for medulla oblongata (2/5) or spinal lesions (5/11). Preferred locations were cerebellum (15/31), often nodulo-cystic appearance, followed by spinal cord (11/31), frequently coming with adjacent syringomyelia. Multiple locations and visceral lesions were found in two-third of the cases. Surgical removal was complete in more than three-quarter of the cases. Mean follow-up duration was 9years. Postoperative mortality rate was 16%. In cerebellar and medulla oblongata locations together, final mRS was ≤1 in 17 of the 20 cases. In spinal cord locations, final McCormick score was ≤2 in all the cases. After delayed follow-up, about two-third of patients experienced recurrence or new progressive CNS lesions.

CONCLUSION

HGB are rare CNS tumors. VHL disease should be considered when an HGB is diagnosed before 30, is located at the spinal cord, comes with multiple other CNS lesions or with typical peripheral lesions. Microsurgical removal is the gold standard treatment and can offer good functional results.

von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors

PURPOSE

: Up to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy.

METHODS

: In a national prospective study, 40 VHL mutation carriers were interviewed about audiovestibular symptoms and had audiological examinations and magnetic resonance imaging of the inner ear. Further, we performed a meta-analysis including all reported endolymphatic sac tumor von Hippel-Lindau disease cases in the literature (N = 140 with 156 endolymphatic sac tumors).

RESULTS

: In the prospective study, endolymphatic sac tumors were suspected based on audiovestibular symptoms, audiometry, and magnetic resonance imaging in 34%, 30%, and 12.5% of subjects, respectively. In total, more than 90% of radiologically diagnosed endolymphatic sac tumors were associated with abnormal audiometric findings. No endolymphatic sac tumor genotype-phenotype correlations were found.

CONCLUSION

: We recommend annual audiometry as a first-line endolymphatic sac tumor screening tool, and in countries where periodic surveillance magnetic resonance imaging of the central nervous system is performed, specific images of the inner ear should be included. Audiometric abnormalities in patients with von Hippel-Lindau disease without magnetic resonance imaging-visible endolymphatic sac tumors could be due to microscopic endolymphatic sac tumors. Determination of audiometric endolymphatic sac tumor characteristics could further target screening and improve endolymphatic sac tumor diagnosis.

Bilateral osteomas arising from the internal auditory canal: case report

OBJECTIVE

Osteomas arising from the internal auditory canal and developing in the cerebellopontine angle have rarely been reported. We present the first case of bilateral osteomas in this region and describe our management strategy.

CLINICAL PRESENTATION

A 30-year-old woman presented with strong vertigo, tinnitus, and hypacusis on the left side. Brain magnetic resonance imaging and computed tomographic scans displayed bilateral cerebellopontine angle osteomas arising from the internal auditory canal. The larger tumor on the left side was found to be compressing the vestibulocochlear nerve.

INTERVENTION

Surgery was performed on the symptomatic side via the retrosigmoid approach, and the tumor was removed completely. The vertigo resolved completely after surgery, and the patient had no further tinnitus attacks. An audiogram showed slightly improved hearing with a mean of 20 dB in the main speech area.

CONCLUSION

Osteomas should be considered in patients with bilateral cerebellopontine angle tumors. Surgical removal might provide resolution of symptoms.

Von Hippel-Lindau (VHL) disease: an update on the clinico-pathologic and genetic aspects

von Hippel-Lindau (VHL) disease is an inherited multisystem familial cancer syndrome caused by mutations of the VHL gene on chromosome 3p25. A wide variety of neoplastic processes are known to be associated with VHL disease. The consequences of the VHL mutations and the pathway for tumor development continue to be elucidated. This paper will detail the variety of tumors associated with VHL disease and discuss the genetic mechanisms that lead to the predisposition for neoplasia.

Endolymphatic sac papillary tumor: a case report and review

Endolymphatic sac papillary tumor (endolymphatic sac adenoma, temporal-mastoid bone adenoma or adenocarcinoma, low-grade adenocarcinoma of potential endolymphatic sac origin, aggressive papillary tumor of the temporal bone, Heffner's tumor) is a rare lesion that involves the temporal bone. This tumor usually appears alone, but in 11-30% of afflicted individuals, it is accompanied by von Hippel-Lindau disease. Endolymphatic sac papillary tumors are destructive tumors that exhibit locally aggressive behavior. They slowly grow into the posteromedial section of petrous temporal bone. The main symptoms produced by these lesions include hearing loss and cranial nerve deficits. Endolymphatic sac papillary tumors develop in two principal patterns that histopathologically form follicular and papillary or solid structures. Those two patterns are usually manifested in the same tumor. Immunochemical analysis of these tumors usually reveals cytokeratin, vimentin, epithelial membrane antigen, and (less frequently) S-100 protein and neuron-specific enolase. Local excision is curative for endolymphatic sac papillary tumors. The currently favored method of treatment consists of excision and long-term follow-up. The role of adjuvant radiotherapy as treatment is controversial. This case report describes an endolymphatic sac tumor in a 22-year-old woman without von Hippel-Lindau disease who had a number of complaints, including deafness in her left ear, complete left-sided facial paralysis, and hoarseness of approximately 8 years' duration.

Low-grade adenocarcinoma of endolymphatic sac origin

We present a case of papillary cystic low-grade adenocarcinoma of endolymphatic sac origin. These tumors are very rare and only a few cases have been reported in literature. They have a protracted clinical course causing progressive invasion and bony destruction. Radiologically, they appear as a heterogenous lobulated vascular mass, invading bone and compressing surrounding structures. Histologically, these tumors are composed of uniform population of cells, resembling normal endolymphatic sac epithelium. This causes considerable diagnostic difficulty. A strong index of suspicion along with clinical and radiological correlation is essential to arrive at a correct diagnosis. In some bilateral cases, association with von Hippel-Lindau disease has been noted. Radical mastoidectomy and temporal bone resection, which may sometimes necessitate sacrifice of cranial nerves, is the treatment of choice.

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.

Endolymphatic sac tumor (low-grade papillary adenocarcinoma) of the temporal bone

The entity which has come to be known as an endolymphatic sac tumor (ELST) has, in the past, been known as adenocarcinoma of endolymphatic sac origin, aggressive papillary tumor of the temporal bone and Heffner's tumor. ELSTs arise in the vicinity of the inner ear and may extend to involve both the posterior fossa as well as the middle ear and the external ear canal, which may complicate the differential diagnosis ELSTs are typically seen in adults, with only rare descriptions in pediatric patients. They may be sporadic tumors or they may arise as part of the symptom complex of von Hippel-Lindau disease. Clinical signs at presentation range from a mass in the external ear canal to sensorineural deafness to cranial nerve palsies. Imaging studies reveal a destructive lesion of the petrous bone which is heterogeneous on MR scanning. Light microscopy reveals two chief patterns: a follicular pattern, reminiscent of thyroid parenchyma; and a papillary/solid pattern. Both patterns are often admixed in the same tumor, and the individual tumor cells are cytologically bland. Immunohistochemically, ELSTs are typically keratin-, vimentin- and epithelial membrane antigen-positive; they are often S-100 protein-positive and neuron-specific enolase-positive as well. ELSTs are difficult to extirpate surgically (owing to their locally aggressive nature); nevertheless, surgical excision remains the mainstay of current therapy. These are slow-growing (albeit locally aggressive) tumors which have only rarely been reported to metastasize; as such, they remain principally a problem of local control.

Von Hippel-Lindau disease

Von Hippel-Lindau (VHL) disease is an uncommon, autosomal dominant hereditary multitumor syndrome caused by germline alterations of the VHL gene, which has been cloned recently and identified as a tumor suppressor gene. The major lesions in VHL disease include hemangioblastomas in the central nervous system and retina, clear cell renal cell carcinomas, pheochromocytomas, pancreatic tumors, epididymal cystadenomas, endolymphatic sac tumors, carcinoid tumors, and multiple cysts of the kidney, pancreas, and epididymis. Compared with sporadic ones, the tumors in VHL disease develop at an earlier age and often multifocally. Histologic features of VHL tumors are characterized by their high degree of vascularization and the presence of a clear cell component. Hypervascularization is induced by overexpression of vascular endothelial growth factor (VEGF), and because the principal function of VHL protein is the negative regulation of hypoxia-inducible mRNAs including VEGF mRNA, inactivation of VHL gene plays critical roles in angiogenesis of the VHL tumors. In addition, since VHL protein is also required for the down-regulation of transcription activity of certain genes for the cell growth and cell cycle, inactivation of VHL gene may contribute to tumorigenesis of the VHL tumors. A significant difference in the frequency of types of VHL gene mutation has been noted among the affected families, known as the genotype-phenotype correlations.

[Endolymphatic sac tumor and von Hippel-Lindau disease. Review of the literature]

This report describes a patient with Von Hippel-Lindau disease revealed by an endolymphatic sac tumor. Endolymphatic sac tumor (EST) was only recently recognized as a manifestation of Von Hippel-Lindau (VHL) disease. EST are vascular lesions that destroy and expand bone. We report a recently treated case of an EST. A 30-year-old woman presented with otalgia and hearing loss. Computed tomography and magnetic resonance imaging showed typical features of an EST. We checked for VHL and found this disease in the patient. VHL disease is a hereditary cancer syndrome caused by germline mutations of the VHL tumor suppressor gene. A molecular diagnosis of VHL is nowadays available, and this has change the clinical management of patients and their families. Diagnosis of VHL has to be suspected in patients with a VHL-related tumor without familial history and especially in those cases of hemangioblastoma or endolymphatic sac tumors. Such patients should be systematically investigated for clinical and molecular evidence of VHL disease.

Hearing preservation surgery for small endolymphatic sac tumors in patients with von Hippel-Lindau syndrome

OBJECTIVE

To determine the incidence of bilateral endolymphatic sac tumors in von Hippel-Lindau syndrome and to describe the technique and results of hearing preservation surgery for small endolymphatic sac tumors in a series of patients with von Hippel-Lindau syndrome.

STUDY DESIGN

Analysis of the literature to determine the incidence of bilateral endolymphatic sac tumors and a retrospective case review of hearing preservation surgery for removal of small endolymphatic sac tumors in four patients with von Hippel-Lindau syndrome.

SETTING

Tertiary care academic medical centers.

PATIENTS

Four patients with von Hippel-Lindau syndrome (three with bilateral endolymphatic sac tumors) and progressive sensorineural hearing loss in which preoperative imaging studies revealed in situ or small endolymphatic sac tumors without ipsilateral labyrinthine destruction.

INTERVENTION

All four patients had complete surgical excisions of the endolymphatic sac tumor via one of three surgical approaches with the goal of hearing preservation. One patient had bilateral surgery.

MAIN OUTCOME MEASURES

Audiometric and radiographic.

RESULTS

Nearly one-third (30.2%) of patients with von Hippel-Lindau syndrome and endolymphatic sac tumors have bilateral disease. All four patients (five ears) maintained serviceable hearing postoperatively after surgical excision of the endolymphatic sac tumor via a variety of approach options.

CONCLUSION

The discovery of a small or in situ endolymphatic sac tumor affords the patient the option of surgical removal with hearing preservation. This is critical in the patient with von Hippel-Lindau syndrome who is at risk for bilateral disease and complete bilateral anacusis if tumor growth progresses.

Mutation of von Hippel-Lindau tumor suppressor gene in a sporadic endolymphatic sac tumor

Endolymphatic sac tumor (ELST) is a low-grade adenocarcinoma of the temporal bone that is presumed to originate from the endolymphatic system. Although ELSTs are extremely rare in the general population, a significant number of studies have documented the occurrence of ELST among patients with von Hippel-Lindau (VHL) disease. Because of the rarity of the tumor, however, few cases of ELST have been analyzed for mutations of the VHL tumor suppressor gene. In this study, we reported a Japanese male patient with sporadic ELST, along with a molecular genetic analysis of the VHL gene. The light microscopic and immunohistochemical features and clinical presentations were typical of ELST. Sequencing studies of the tumor DNA disclosed a G to T substitution of nucleotide 564, which resulted in an amino acid substitution (Trp to Cys). This is the first report of the VHL gene mutation in a sporadic Japanese case of ELST.

Cytology of endolymphatic sac tumor

A 77-year-old man presented with decreased mental status and an enhancing partially cystic tumor along the left tentorium on magnetic resonance imaging after mastoidectomy and petrosectomy for an "auditory canal tumor." Smears of the aspirated cyst fluid revealed rare epithelial cell clusters, some with papillary features, foamy macrophages, and blood. The cells were orderly, with fairly bland nuclei and well-defined cell borders. The cell block contained similar epithelium, with cells containing eosinophilic and focally vacuolated cytoplasm, some with pigmented granules resembling hemosiderin. Numerous foam cells were also present. Review of the patient's previous and concurrent resection material showed an endolymphatic sac tumor, a rare neoplasm that arises in the endolymphatic sac in the temporal bone. The previously undescribed cytologic features of this rare neoplasm are discussed.

Endolymphatic sac tumor associated with a von Hippel-Lindau disease patient: an immunohistochemical study

The authors report a case of endolymphatic sac tumor (ELST) associated with Von Hippel-Lindau disease (VHL). A 20-year-old female VHL patient received a resection of a cerebellar hemangioblastoma 3 years ago and she had a co-existing of left petrous tumor. The petrous tumor showed a remarkable progression in 3 years and was resected subtotally. Histologically, the resected petrous tumor showed a papillary structure containing cuboidal or columnar cells with fibrous stroma and numerous microvessels and destructed temporal bone, all of which are consistent with ELST. We studied the expression of various kinds of cytokeratins (CKs) immunohistochemically and found distinct expression of CKs (CAM 5.2, 34betaE-12, CK7, CK8 and CK19), but not for CK10/13 or CK20. Vascular endothelial growth factor and neuron specific enolase showed strong immunoreactivity in the tumor cells. CD34 also had weak expression. Ki-67 antigen (MIB-1) immunoreactivity was found in focal areas, and the labeling index in the highest-density area was 48.9%. These findings suggest that vascular endothelial growth factor overexpression is an important factor for angiogenesis in ELST, much like other VHL-associated tumors, and that ELST may have a more highly aggressive component than the low-grade malignancy noted in previous reports.

Endolymphatic sac tumours

This review article surveys clinical and pathological literature on endolymphatic sac tumours (ELST) and summarizes characteristics that describe the entity. ELST are rare neuroectodermal neoplasms in the petrous bone, originating from inner ear structures. They can be encountered sporadically or in von Hippel-Lindau disease. The most prominent symptom is sensorineural deafness. Historically, nomenclature of invasive adenoid tumours in the petrous bone has been divergent, the term papillary adenocarcinoma used most frequently. Histologically, they have a follicular or papillary and adenoid pattern that can be easily confused with various other neoplastic conditions including metastatic carcinoma. It remains to be verified whether similar tumours (papillary adenocarcinomas) can originate from the middle ear. Middle ear adenomas have a similar appearance but probably originate from neural crest cells in the middle ear. ELST can express a variety of epitopes (including cytokeratin and neuroectodermal markers) which can be detected immunohistochemically. In cases in von Hippel-Lindau disease the cerebello-pontine angle should be included in routine radiological examinations to detect ELST before the tumours lead to deafness. In apparently sporadic cases of ELST, genetic testing for von Hippel-Lindau disease should be considered. Correct distinction of ELST from metastatic carcinoma prevents futile searches for unknown primary tumours.

Genotype-phenotype correlations in von Hippel-Lindau disease

A total of 146 intragenic germline mutations of the von Hippel-Lindau (VHL) gene are known and this figure is still increasing. To date, information for mutation-specific genetic counselling is insufficient, since either the total number of carriers is very low or clinical information and investigation of symptomatic and asymptomatic is incomplete. This review summarizes all known mutations and includes the centres which performed the mutation analyses and may provide further information regarding specific mutations.