Endolymphatic sac tumor: unique features of two cases and review of the literature

Delayed yet effective response of an endolymphatic sac tumor to radiosurgery: case report focusing on its radio-biological behavior

Endolymphatic sac tumors (ELST), though benign are locally invasive lesions. Owing to its vascularity, complete surgical resection is often not possible and adjuvant gamma knife radiosurgery (GKRS) is advocated to control tumor growth. These lesions do not uniformly respond to radiation therapy in the initial phase and their early radiobiological course after GKRS is less understood. We discuss a case of residual ELST where a mild increase was noted at 36 months following GKRS and then regressed completely after a decade. This report possibly has the longest follow-up revealing the true efficacy of GKRS in these tumors. ELST shows a variable response in the early years after GKRS. They may remain static, regress or increase in size. One should be aware of these patterns of early radiological responses and a long term follow up is warranted as some lesions may show radiosurgical effectiveness after a long latent period.

Case Series and Systematic Review of Radiation Outcomes for Endolymphatic Sac Tumors

OBJECTIVE

Surgery is the primary treatment modality for endolymphatic sac tumors (ELST). Two case examples are presented to highlight some rare instances when radiation therapy may be used. The outcomes following radiation therapy for ELST are controversial. This report systematically reviews those outcomes and compares results between external beam radiation and stereotactic radiosurgery.

DATA SOURCE

In accordance with PRISMA guidelines a systematic literature search of the Ovid Medline, Embase, Scopus, Cochrane library, and clinicaltrails.gov databases was performed in August 2017.

STUDY SELECTION

Twenty-two studies met inclusion criteria and report ELST outcomes following radiation therapy. Additional data on tumor size, previous surgery, radiation modality, and radiation dosing was collected.

DATA EXTRACTION

The methodological quality was independently assessed by three reviewers. The included studies were small, heterogeneous case reports with a low level of evidence, and several sources of bias.

DATA SYNTHESIS

The primary outcome was tumor control following radiation, defined as no growth. A comparative analysis of external beam versus stereotactic radiation was performed.

CONCLUSION

Forty-six tumors from 42 patients were independently analyzed. The overall tumor control rate was 67.4%. When analyzing patients in which tumor was present at the time of radiation, external beam radiation controlled 9 of 19 tumors (47.4%) while stereotactic radiosurgery controlled 14 of 18 tumors (77.8%). The effect size of 30.4% favors stereotactic radiosurgery, but the wide confidence interval (-4.4 to 57.4%) limits what conclusions can be drawn. Radiation for ELST remains controversial and more long-term data is needed.

Endolymphatic sac tumor at the cerebellopontine angle: A case report and review of literature

INTRODUCTION

Endolymphatic sac tumors may present as sporadic or may be associated with Von Hippel-Lindau disease. Patients generally present with hearing loss, tinnitus and vertigo. The tumor is highly vascular which may lead to erosion of the adjacent bony and vascular structures, resulting in heavy bleeding during surgery.

PRESENTATION

A twenty-five year-old female presented with a five year history of chronic ear discharge, left sided facial weakness, and recent onset of ataxia.

DISCUSSION

The unusual clinical presentation made management challenging, in large part due to profuse bleeding. Pre-operative embolization of the vessels supplying the tumor may reduce blood loss during surgical excision. Radiotherapy could be considered for any residual tumor.

CONCLUSION

The patient was diagnosed with an endolymphatic sac tumor of sporadic origin which presented at the cerebellopontine angle and was managed with a multidisciplinary approach.

Current Treatment of Endolymphatic Sac Tumor of the Temporal Bone

An endolymphatic sac tumor (ELST) is a rare, indolent but locally aggressive tumor arising in the posterior petrous ridge. Patients present with sensorineural hearing loss and tinnitus. As the tumor progresses, patients may experience vertigo, ataxia, facial nerve paresis, pain and otorrhea. Most patients present in their 4th or 5th decade with a wide age range. Patients with von Hippel-Lindau disease have an increased likelihood of developing ELST. Histologically, ELST is a low-grade adenocarcinoma. As it progresses, it destroys bone and extends into adjacent tissues. The likelihood of regional or distant metastases is remote. The optimal treatment is resection with negative margins. Patients with positive margins, gross residual disease, or unresectable tumor are treated with radiotherapy or radiosurgery. Late recurrences are common, so long follow-up is necessary to assess efficacy. The likelihood of cure depends on tumor extent and is probably in the range of 50-75%.

Gamma knife radiosurgery in the management of endolymphatic sac tumors

Background

Although widely regarded as rare epithelial tumors with a low grade of malignancy, endolymphatic sac tumors (ELST) often lead to disabling petrous bone destruction and significantly impairing symptoms at the time of primary diagnosis and/or recurrence. ELST is not uncommon in von Hippel Lindau (VHL) patients. Although open surgery is regarded as the best treatment option, recurrence remains a challenge, particularly when gross tumor resection (GTR) is deemed unachievable due to topographic conditions. Tumor recurrence successfully treated with fractionated radiotherapy and radiosurgery have been reported in selected cases. We present the case of a patient with recurrent ELST treated with salvage gamma knife radiosurgery (GKRS) adding a review of current literature.

Case Description

A 65-year-old patient underwent GKRS of an unresectable, recurrent ELST. Tumor volumetric analysis showed almost 15% increase in tumor volume in the 4 months between the pre-GKRS magnetic resonance imaging (MRI) and the stereotactic MRI (s-MRI) at treatment. Follow-up MRI at 12 and 20 months showed significant decrease in local tumor volume, decreased contrast enhancement and no perifocal edema. The patient's general and neurological status remains stable to the present day.

Conclusion

In the present case, GKRS was effective in the management of a recurrent ELST over the course of 20 months. Because of ELSTs recurrence potential, long-term follow up is required. The present case as well as previous reports might suggest a possible salvage/adjunctive role of radiosurgery in the management of ELST. Further studies are deemed necessary.

Treatment of endolymphatic sac tumour (Papillary adenocarcinoma) of the temporal bone

AIM

To define a better treatment of sporadic endolymphatic sac tumours (ELST) analysing our experience and literature available data.

BACKGROUND

ELST can arise as sporadic case (rare) or as a part of von Hippel-Lindau (VHL) disease. It is a low grade malignancy with local spread by continuity.

MATERIALS AND METHODS

we described our experience with 7 cases with up to date follow up.

RESULTS

Five cases were free of disease after first surgical procedure. One case had recurrence in the temporal lobe after 12 years. One case had two surgical procedures followed by irradiation and died five years after radiotherapy with a slow disease progression.

CONCLUSION

With increasing expertise in the skull base surgery, complete tumour excisions are achieved in majority of the more recent cases and appear to be the treatment of choice. External irradiation is also used as palliative measures with doubtful effectiveness. Some recent reports showed encouraging results with gamma knife radiosurgery.

Management of primary and recurrent endolymphatic sac tumors

OBJECTIVE

To report the clinical presentation, management strategies, and outcomes of 14 endolymphatic sac tumors (EST).

STUDY DESIGN

Retrospective case series.

SETTING

Collective experience accrued from 2 tertiary referral centers.

PATIENTS

All patients with ESTs.

INTERVENTION

Microsurgery, stereotactic radiosurgery (SRS).

MAIN OUTCOME MEASURE(S)

Treatment-related morbidity, recurrence.

RESULTS

Fourteen ESTs (13 patients) met inclusion criteria. Eight tumors were sporadic, and 6 were associated with von Hippel-Lindau disease (VHL). Twelve lesions were managed primarily, whereas 2 were referred for treatment of sizable recurrences after subtotal resection. Including all patients, the median age at diagnosis was 36 years, and the median duration of posttreatment follow-up was 78 months. Among primary tumors, the median delay between symptom onset and diagnosis was 36 months, and the median tumor diameter at presentation was 23 mm with most lesions demonstrating intracranial involvement. Subjects with VHL frequently presented with smaller, less extensive tumors and were more commonly female compared with patients with sporadic disease. Of the 9 ESTs presenting with normal facial nerve function, 8 maintained good (HB 1-2) posttreatment capacity. Two of 5 ears with useful preoperative hearing maintained pretreatment hearing levels after surgery. One of 12 tumors managed primarily recurred after microsurgical resection. Primary SRS was used in 1 medically infirm patient providing durable tumor control (94 mo) at last follow-up. Among recurrent tumors, 2 were managed successfully with reexcision, whereas 1 underwent salvage surgery followed by 2 sequential treatments of SRS for 2 separate intracranial recurrences; no in-field recurrence has been detected to date.

CONCLUSION

ESTs are rare primary neoplasms of the temporal bone that may occur sporadically or in association with VHL. Outcomes after treatment of small less-extensive tumors are favorable compared with patients with advanced primary or recurrent disease. Furthermore, subtotal resection carries a high risk of bulky or multifocal recurrence. As such, early gross total resection remains the management strategy of choice for primary and recurrent ESTs; however, SRS should be considered in poor surgical candidates or in cases of focal intracranial recurrence when the morbidity of salvage surgery is high.

Endolymphatic sac tumour: case report and literature review

Objective:

To increase awareness of the presentation, diagnostic difficulties and management of endolymphatic sac tumours.

Case reports:

A 79-year-old man with a 6-month history of unilateral hearing loss, tinnitus and vertigo, who was suspected to have an endolymphatic sac tumour on imaging, underwent successful transmastoid-translabyrinthine resection. A 53-year-old man with unilateral hearing loss and pulsatile tinnitus underwent subtotal resection of a suspected paraganglioma, which was identified histologically. Due to interval growth, gamma knife radiosurgery was performed followed by subtotal petrosectomy, at which juncture an endolymphatic sac tumour was reported.

Methods:

A review of the world literature was carried out using Medline, which identified less than 150 reported cases of endolymphatic sac tumour.

Conclusion:

Endolymphatic sac tumours are rare lesions of the petrous temporal bone. Although benign, they can be locally destructive. At present, there is no consensus regarding the management and long-term follow up of these tumours. Surgical resection is usually favoured, although treatment with radiotherapy and gamma knife surgery has also been reported.

Surgical treatment of endolymphatic sac tumor

The objective of this study was to understand the clinical characteristics of endolymphatic sac tumor and to optimize its diagnosis and treatment. We carried out a retrospective review of 11 patients diagnosed as having endolymphatic sac tumor based on operative findings and pathological features, and their clinical manifestations, differential diagnosis, and surgical approaches are discussed in detail. The lesions of 10 cases were completely surgically resected, two cases via the mastoid approach, 8 cases via the oto-cervical or cranio-oto-cervical combined approach. In one case the tumor was partially removed and the patient received adjuvant radiotherapy. In operation, four cases had facial-hypoglossal neural anastomosis, two cases had great auricular nerve graft, and in four cases the facial nerve integrity remained. Survival follow-up data range from 14 months to 10 years. We conclude that endolymphatic sac tumor is very rare and easily misdiagnosed. Reasonable surgical treatment can provide a good prognosis.

Tumors and pseudotumors of the endolymphatic sac

This article reports on the presentation, diagnosis, management, and treatment outcomes of lesions of the endolymphatic sac in patients treated at a tertiary neurotology referral center. It summarizes survival results in the largest series groups and presents a new diagnostic entity of pseudotumor of the endolymphatic sac. The study includes retrospective review of all patients diagnosed with lesions of the endolymphatic sac within our practice between 1994 and 2005 as well as review of the literature. The primary outcome measure was survival, and the secondary outcome measure was disease-free survival following definitive resection. Postoperative complications were assessed. Survival characteristics of the largest reported case series groups were reviewed. Five cases of endolymphatic sac lesions were identified. Of these, three were true endolymphatic sac tumors and two were inflammatory pseudotumors of the endolymphatic sac. All three of the endolymphatic sac tumors patients survived (100%), and two of the three had disease-free survival (67%). Two of three patients maintained persistent facial paresis postoperatively. Both patients with benign pseudotumors survived (100%). Our study concluded that endolymphatic sac tumors are rare neoplasms of the temporal bone that, although locally aggressive and invasive, have excellent prognosis for survival with complete resection. We report a new entity of pseudotumor of the endolymphatic sac that mimics true sac tumors in every respect on presentation but which is non-neoplastic in origin.

Endolymphatic sac tumors : report of four cases

Endolymphatic sac tumor is rare, locally aggressive hypervascular tumor of papillary structure, arising from the endolymphatic duct or sac in the posterior petrous bone. We present four cases with this tumor. Two patients were male and the other two were female. Age of each patient was 15, 52, 58, and 67 years. Three patients presented with progressive hearing loss and sustained vertigo for months to years and another one was referred for the tumor detected in routine medical check-up. Preoperative embolization was performed in 3 patients. Complete excision of the tumor was achieved in all patients using translabyrinthine or retrosigmoid approach. Herein, we describe the clinical and radiographic features, surgical treatment and pathologic findings with a review of the literature.

Surgery for endolymphatic sac tumor: whether and when to keep hearing?

CONCLUSION

Endolymphatic sac tumors (ELSTs) are locally invasive, osteolytic, and hypervascular tumors. If the labyrinth has not been invaded, the hearing should be preserved in operation.

OBJECTIVE

To summarize three cases of ELST and discuss whether to keep hearing in the surgical treatment of ELST.

SUBJECTS AND METHODS

Complete otorhinolaryngological examinations with audiologic, vestibular, and neurologic evaluations were performed. CT and MRI scans were carried out before operation and in the course of follow-up. The patients underwent radical removal of the tumor through a transmastoid approach and accepted postoperative radiotherapy. In two of them, the structure of the labyrinth and facial nerve were preserved in operation.

RESULTS

Histopathologic examinations agreed with features of an ELST. Patients suffered transitory vertigo shortly after operation, and so far, they are alive and well without further cranial nerve involvement. Case 3 patient has good hearing and facial nerve function now. No residual or recurrent tumor was detected on the postoperative MRI images.

Contrasting behavior of endolymphatic sac tumors: a report of 2 cases and literature review

BACKGROUND

Endolymphatic sac is an established source of low-grade neoplasms, posing a difficult problem in local tumor control.

CASE DESCRIPTION

Two cases of endolymphatic sac tumors are described in detail with regard to their clinical presentation and radiological findings. Both cases had diametrically opposite clinical outcomes in spite of repeated surgical interventions. A case with severe paraneoplastic syndrome and death after "cancer cachexia" is described.

CONCLUSIONS

Although endolymphatic tumors are known for their low-grade aggressiveness, in occasional cases, they may behave in a highly malignant behavior. The present communication highlights the contrast in clinical outcome and makes the clinician cautious of this special subgroup of tumors with a highly aggressive nature.

Small papillary tumor in the saccule

Papillary tumors of the ear are aggressive neoplasms. Previously, a tumor growing in the saccule had not been reported. We report a tumor found incidentally in the saccule of a patient. Serial sections of both temporal bones of the patient were studied in order to analyze the tumor's origin and influence on audio vestibular function. In the right inner ear, there was a small papillary lesion in the saccule, which looked like a papillary tumor without aggression invasion. The tumor was located in the membranous labyrinth of the saccule, not in the endolymphatic duct and sac. It was not related to Von Hippel-Lindau (VHL) disease, nor was it an endolymphatic sac tumor. The tumor did not influence the hearing and vestibular function in the right ear, although this patient presented a severe sensorineural hearing loss and vestibular function loss because of the vestibular schwannoma in the left ear.

[Benign and malignant lesions in the region of the inner ear and cerebellopontine angle]

Tumorous lesions in the region of the inner ear and cerebellopontine angle are very rare and can be classified into benign and malignant disease forms. This contribution presents and explains the CT and MRI characteristics of these tumors.High-resolution computed tomography (HRCT) in the axial projection is applied for evaluation in the high-resolution bone window. The coronary slices can be reconstructed from the axial datasets or in individual cases examined in the coronary plane.HRCT excellently demonstrates osseous lesions and in individual cases - e.g., exostoses - it can simply suffice to perform HRCT of the temporal bone, while HRCT is also excellent for detecting osseous lesions to determine whether the tumor is benign or malignant.MRI, on the other hand, excellently shows the extent of tumor spread because of its superb soft tissue contrast. Consequently, HRCT and MRI images of the inner ear and cerebellopontine angle provide meaningful information for visualization and classification of tumorous lesions. The two methods should not be considered as competing but rather as complementary and among other aspects exert considerable influence on the therapeutic approach.

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.