Surgical management of endolymphatic sac tumor: classification, outcomes and strategy. A single institution's experience.

PURPOSE: To review the resections of endolymphatic sac tumor (ELST) and describe our experience in the surgical management of ELST. METHODS: Retrospective investigation of consecutive patients who underwent resection of ELSTs at our hospital between 1999 and 2019. The symptoms, diagnosis, surgical findings, and outcomes were analyzed to develop a tumor staging system and corresponding surgical strategy. RESULTS: Retrospective review revealed the surgical treatment of 22 ELSTs. Based on intraoperative findings of tumor extent and size, ELSTs were classified into two types. Type-I (n = 6) referred to the small tumors that were locally confined with limited invasion of semicircular canals and dura; type-II (n = 16) referred to the large tumors that presented extensive erosion of at least one anatomic structure apart from the semicircular canals and the dura around endolymphatic sac. In this case series, Type-I ELST is amenable to resection through a transmastoidal approach, and subtotal petrosectomy is appropriate for the resection of type-II ELST. Sensorineural hearing loss (SNHL) is the most commonly preoperative symptom in both two types of cases. Five type-II ELSTs experienced recurrence and underwent reoperation, whereas all type-I ELSTs did not. CONCLUSION: ELST usually results in SNHL (95%) at the time of diagnosis. The surgical strategy and prognosis of ELST resections are different between type-I and type-II: type-I ELST is amenable to transmastoidal approach with the preservation of facial nerve, whereas type-II ELST increase the surgical difficulty and the risk of recurrence, and subtotal petrosectomy is the basic requirement for the resection of type-II ELST.

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.

Endolymphatic sac tumor: single-institution series of seven cases with updated review of literature.

BACKGROUND: Endolymphatic sac tumour (ELST) is a rare low-grade locally aggressive neoplasm arising from the endolymphatic duct or sac. It presents mostly with vestibulo-cochlear symptoms either sporadically or as part of von Hippel-Lindau (VHL) syndrome. Micro-neurosurgical excision remains the cornerstone of therapy with the role of radiotherapy (RT) being controversial. This is a clinico-pathological analysis of consecutive ELST patients presenting to a single-institution in India. METHODS: Neuropathology database of a tertiary-care comprehensive cancer centre was searched electronically to identify consecutive patients with histopathological diagnosis of ELST registered at the institute over last one decade. Data regarding demographic profile, clinical presentation, histopathological features, treatment details and outcomes were retrieved from electronic medical records for this retrospective analysis. RESULTS: Electronic search identified seven unique patients with biopsy-proven ELST registered at the institute between 2009 and 2020. Median age of the study cohort was 39 years (range 24-65 years) with strong male predilection (5:2 ratio) and left-sided preponderance (71%). Most common presenting symptoms were hearing loss (86%) and earache (71%) on affected side followed by headache (43%). All patients underwent maximal safe resection at initial diagnosis and were followed-up closely with periodic surveillance imaging. Two patients underwent salvage RT using high-precision conformal techniques at recurrence/progression. CONCLUSION: ELST is a rare low-grade locally aggressive neoplasm that arises generally as part of VHL syndrome or sometimes sporadically. Gross total resection provides the best chance of cure with RT being reserved for unresectable disease, large residue, medical inoperability, or as salvage therapy for recurrent/progressive tumor.

Symptoms and clinical features in patients affected by endolymphatic sac tumor: a systematic review and meta-analysis.

PURPOSE: Most ELST data in the literature are case studies or limited to small cohorts (< 16 patients). We evaluated the main clinical signs observed at endolymphatic sac tumor (ELST) diagnosis in patients with or without Von Hippel-Lindau disease. METHODS: We conducted a comprehensive literature search in PubMed, Scopus, and Web of Science. We included studies with at least 1 patient, of any age, affected by sporadic or VHL-related ELSTs reporting levels of hearing loss and facial nerve function and a comprehensive description of presenting symptoms at ELST diagnosis. We combined data for proportional meta-analysis. p values of 0.05 were considered statistically significant. Methodological quality was evaluated. Analyses were performed with MedCalc 14.8.1 software. RESULTS: A total of 26 studies, including 113 patients and 118 cases of ELSTs were included. Pooled proportion rates (95% CI) of overall hearing loss was 88.7%, (82.4-93.4), severe hearing loss was 21.6% (12.8-32.1) profound hearing loss was 39.8% (28.7-51.5), vertigo/imbalance was 42.0% (33.8-50.5), tinnitus was 61.8% (53.4-69.8) and facial nerve palsy was 30.6% (23.2-38.9). Generally, symptoms were homogeneous or moderately heterogeneous among included studies. CONCLUSION: This is the first systematic review of clinical presentations at ELST diagnosis. The most serious clinical events include profound hearing loss and facial impairment. Fluctuating hearing loss, tinnitus and vertigo are frequently reported and may confound correct and prompt ELST diagnosis.

The endolymphatic sac tumor: challenges in the eradication of a localized disease.

OBJECTIVE: Identify the critical points that lead to recurrences and lack of radicality in endolymphatic sac tumors (ELSTs). STUDY DESIGN: Retrospective case study and review of the literature. SETTING: Tertiary referral center. PATIENTS: Thirteen cases of ELST were included in the study and their preoperative, intraoperative and postoperative data were analyzed and compared to a review of the literature. INTERVENTION(S): Therapeutical. MAIN OUTCOME MEASURE(S): Prevalence of recurrent and residual tumors, comparison to the literature and analysis of ELST characteristics. RESULTS: Diagnosis was made 26 ± 17 months after the onset of symptomatology, and an ELST was preoperatively suspected in only six cases. At the time of surgery, 10 patients suffered from hearing loss. Preoperative symptoms or audiometry could not predict labyrinth infiltration, although speech discrimination scores were significantly associated with labyrinth infiltration (p = 0.0413). The labyrinth was infiltrated in 8 cases (57.1%), and in 7 cases (46.7%) the tumor eroded the carotid canal, whereas 6 cases (40%) presented an intradural extension. A gross total resection was achieved in 11 cases. There were two residual tumors, one of which because of profuse bleeding, and one recurrence (23.1%). A mean of 22.8% of recurrent or residual tumors are described in the literature based on 242 published cases, in more than half of the cases as a consequence of subtotal tumor resection (STR). CONCLUSIONS: Recurrence derives mostly from the difficulty to identify the extension of the tumor due to the extensive bone infiltration. Accurate diagnosis and correct preoperative planning, with embolization when possible, will facilitate surgery and avoid STR due to intraoperative bleeding. Long follow-ups are important in order to avoid insidious recurrences.

Clinicoradiologic characteristics of endolymphatic sac tumors.

PURPOSE: Endolymphatic sac tumor (ELST) is a rare, slow-growing, and low-grade malignant tumor arising from the endolymphatic sac in the posterior petrous bone. The purpose of this study is to describe the clinical and radiologic features, and investigate the clinicoradiologic correlation of ELST. METHODS: We retrospectively reviewed the clinical, computed tomography (CT), magnetic resonance imaging (MRI), and pathologic findings of 14 patients with 15 ELSTs. RESULTS: Patients comprised of eight women and six men with a mean age of 42.3 years at the time of diagnosis and 35.2 years at the time of initial symptoms. The mean interval between initial symptoms and diagnosis was 84.7 months. The most frequent cochleovestibular symptom was hearing loss in 14 patients (100%); other cochleovestibular symptoms were tinnitus in eight patients (57.1%), vertigo in three patients (21.4%), and aural fullness in three patients (21.4%). Ten patients (71.4%) presented with facial paralyses and five patients (14.3%) presented lower cranial nerve deficits. CT findings revealed spiculated, stippled, or reticular high density within the tumors. The lesions involved mastoid cells, vertical facial nerve canal, semicircular canal, cochlea, tympanum, jugular foramen, internal auditory canal, or petrous apex. On the available MRI, all the eight lesions showed patchy and/or speckled hyperintensity on unenhanced T1WI. Five lesions showed flow voids on T2WI and T1WI. Three lesions had blood fluid levels within cysts. CONCLUSION: CT and MRI findings of ELSTs are associated with clinical features. Imaging tests should be performed to identify ELSTs early and ensure greater potential for hearing preservation in patients with cochleovestibular symptoms.

Clinicopathologic study of endolymphatic sac tumor (ELST) and differential diagnosis of papillary tumors located at the cerebellopontine angle.

We investigated the clinicopathologic features and immunophenotypes of 10 cases of endolymphatic sac tumor (ELST) and compared them with other papillary tumors, including eight cases of choroid plexus papilloma (CPP), three cases of atypical choroid plexus papilloma (ACPP), two cases of papillary ependymoma (PE), three cases of papillary meningioma (PM) and two cases of metastatic carcinoma (MC) the at cerebellopontine angle (CPA). The age at onset of ELST ranged from 13 to 39 years. The male-to-female ratio was 1:1. The clinical presentations were primarily ear-related symptoms. The temporal bones showed extensive destruction. Histologically, the important characteristics for differential diagnosis with CPP, which is most similar to ELST, include the quantity of blood vessels, the nuclei location at apical surface of the papillary, clear cytoplasm cells sometimes with visible vacuoles, psammoma bodies and dura or bone invasion. Immunohistochemistry stains for AE1/AE3, cytokeratin CK)5/6, epithelial membrane antigen, CK8/18, S-100, and synaptophysin are helpful in diagnosis of ELST. In ELST, ultrastructure of uniform 2 µm vesicles in cytoplasm was seen, and gene analysis also showed missense mutation in exon 3. This study indicates that the above histological features combined with immunohistochemistry findings are important for making the correct diagnosis. Gene analysis should be used in patients without medical history to exclude von Hippel-Lindau disease.

A Rare Case of Angiofibroma Presenting as an Endolymphatic Sac Tumor.

A 30-year-old man presented with minute-long episodes of vertigo and severe autophony. CVEMP showed a decreased threshold when testing the left side, potentially indicating SSCD. A subsequent MRI demonstrated a multi-lobulated, cystic mass in the temporal bone and the radiological diagnosis at that time was ELST. Tumor excision was performed, and microscopic examination of the excised material revealed fibrovascular tissue without signs of papillary or cystic projections. The conclusion of the histological assessment rendered a diagnosis of angiofibroma. We were unable to find a previous report of ENA originating around the endolymphatic sac. Laryngoscope, 134:1897-1900, 2024.

Endolymphatic sac tumor: An urgent case presenting acute intracranial hypertension successfully treated with suboccipital decompressive craniectomy - 8 years of follow-up.

Background: Endolymphatic sac tumor (ELST) is a rare lesion. It may be sporadically or associated with Von Hippel-Lindau syndrome. Progressive audiovestibular symptoms characterize the typical clinical presentation. Here, we report a unique case of ELST with acute intracranial hypertension (IH) due to tumor compression, successfully treated with an urgent suboccipital decompressive craniectomy (SDC). Case Description: A 33-year-old woman previously underwent a biopsy and ventriculoperitoneal shunt. The histopathological finding revealed an ELST. One year later, she developed headache, vomiting, and somnolence due to brainstem compression. An urgent SDC was performed. One month later, preoperative endovascular embolization and partial tumor resection were carried out. After 6 months adjuvant radiotherapy (RT) therapy was administered. She has been under follow-up for 8 years since the last surgical procedure, and the tumor remains stable. Conclusion: ELST generally has a progressive clinical course. This is a unique case with acute IH due to tumor compression. The tumor's high vascularity and the unavailability of endovascular embolization precluded its resection. SDC was an alternative approach. The final treatment included tumor embolization, surgical resection, and RT. No progression was observed for 8 years after the last procedure, and long-term follow-up is warranted.

Systematic Review of Endolymphatic Sac Tumor Treatment and Outcomes.

OBJECTIVE: Endolymphatic sac tumors are rare neoplasms originating in the endolymphatic sac. Current literature is limited to case reports and small case series. The objective of this study was to systematically review the literature to better describe clinical presentation, treatment options, and outcomes in endolymphatic sac tumors. DATA SOURCE: PubMed, Embase, and Cochrane Library. REVIEW METHODS: A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines describing human endolymphatic sac tumors. Risk of bias was assessed using a validated critical appraisal checklist for case series. Studies without inclusion of individual patient characteristics, corresponding treatments, and outcomes were excluded. Heterogeneity of data precluded meta-analysis. RESULTS: A total of 82 studies met inclusion criteria, and 253 discrete tumors were analyzed. A total of 23.4% of patients had von Hippel-Lindau disease. Von Hippel-Lindau-associated tumors affected females to males in a 2.4:1 ratio. Patients with von Hippel-Lindau disease displayed earlier average age at diagnosis compared to the sporadic cohort. Surgery was the primary treatment modality and was performed in 88.9% of cases. Adjuvant radiation therapy was employed in 18.7% of cases; 16.2% cases recurred, and 10.6% had progression of residual disease after treatment. Mean time to recurrence or progression was 53.1 ± 52.4 months with a range of 3 to 240 months. CONCLUSION: Endolymphatic sac tumors require a high degree of suspicion for early diagnosis. Complete resection is the standard of care. No strong evidence supports routine use of adjuvant radiation therapy. Given the high rate of recurrence and wide-ranging time to recurrence, long-term follow-up is necessary.

[Endolymphatic sac tumor with intralabyrinthine hemorrhage: a case report].

A 27-year-old female patient suffering endolymphatic sac tumor with intralabyrinthine hemorrhage was reported. The patient had hearing loss in the left ear with continuous tinnitus, and MRI showed the soft tissue shadow of endolymphatic sac. Considering that the tumor involved semicircular canal and vestibule,endolymphatic cyst tumor resection was performed by labyrinth route. After surgery, there was no cerebrospinal fluid leakage and facial nerve function was normal. More importantly, enhanced MRI of temporal bone showed no tumor recurrence 1 year after surgery.

Cytological features of endolymphatic sac tumors: Case studies with review of literature.

Endolymphatic sac tumors are extremely rare, locally aggressive neoplasms that arise from the endolymphatic sac or duct, primarily in the intraosseous portion. These neoplasms show diverse histomorphological architectures and despite a bland cytologic appearance, can locally recur. Although the clinicopathological and radiological features of this entity are well characterized, the literature on cytological features is extremely sparse. Herein, we describe the cytological features of the endolymphatic sac tumors and discuss the relevant differential diagnoses.

Endolymphatic Sac Tumor Screening and Diagnosis in von Hippel-Lindau Disease: A Consensus Statement.

Objective Endolymphatic sac tumors (ELSTs) are a frequent cause of hearing loss and other audiovestibular dysfunction in patients with von Hippel-Lindau disease (VHL). Unified screening recommendations for VHL patients have not been established. To develop consensus guidelines, the VHL Alliance formed an expert committee to define evidence-based clinical screening recommendations. Patients and Methods Recommendations were formulated by using the Grading of Recommendations, Assessment, Development, and Evaluation framework after a comprehensive literature review. Results Diagnosis of ELSTs in VHL requires a combination of clinical evaluation and imaging and audiometric findings. Audiovestibular signs/symptoms are often an early feature of small ELSTs, including those that are not visible on imaging. Diagnostic audiograms have the greatest sensitivity for the detection of ELST-associated sensorineural hearing loss and can help confirm clinically relevant lesions, including those that may not be radiographically evident. Magnetic resonance imaging (MRI) can be a more specific test for ELSTs in VHL particularly when supplemented with computed tomography imaging for the identification of small tumors. VHL patients between the ages 10 and 60 years carry high preponderance for ELST presentation. Conclusion We recommend that clinical evaluation (yearly) and diagnostic audiograms (every other year) be the primary screening tools for ELSTs in VHL. We suggest that screening be performed between the ages 11 and 65 years or with the onset of audiovestibular signs/symptoms for synchronicity with other testing regimens in VHL. We recommend that baseline imaging (MRI of the internal auditory canals) can be performed between the ages of 15 and 20 years or after positive screening.

Synchronous Presentation of Rare Brain Tumors in Von Hippel-Lindau Syndrome.

Von Hippel-Lindau (VHL) disease is a heritable cancer syndrome in which benign and malignant tumors and/or cysts develop throughout the central nervous system (CNS) and visceral organs. The disease results from mutations in the VHL tumor suppressor gene located on chromosome 3 (3p25-26). A majority of individuals (60-80%) with VHL disease will develop CNS hemangioblastomas (HMG). Endolymphatic sac tumor (ELST) is an uncommon, locally aggressive tumor located in the medial and posterior petrosal bone region. Its diagnosis is based on clinical, radiological, and pathological correlation, and it can occur in the setting of VHL in up to 10-15% of individuals. We describe a 17-year-old male who presented with a chief complaint of hearing loss. Brain and spine Magnetic Resonance Imaging documented the presence of an expansive lesion in the left cerebellar hemisphere, compatible with HMG in association with a second cerebellopontine lesion compatible with ELST. The peculiarity of the reported case is due to the simultaneous presence of two typical characteristics of VHL, which led to performing comprehensive genetic testing, thus allowing for the diagnosis of VHL. Furthermore, ELST is rare before the fourth decade of life. Early detection of these tumors plays a key role in the optimal management of this condition.

Biological Treatments of Neurofibromatosis Type 2 and Other Skull Base Disorders.

Studies of genomic alterations that occur in skull base tumors have provided information regarding biological aberrations that are necessary for the growth and maintenance of these tumors. This has led to the development and initiation of clinical trials incorporating biological treatments for many skull base tumors. The exciting developments of molecularly targeted therapy for the treatment of skull base tumors may provide noninvasive therapeutic options for patients that can be used either alone or in combination with surgery and/or radiation therapy. Future analysis and continued scientific discovery of treatments for skull base tumors can lead to improved outcomes in patients.

Papillary Mucinous Adenocarcinoma of the Endolymphatic Sac: A Rare Middle Ear Neoplasm.

Glandular neoplasms of the temporal-mastoid region and endolymphatic sac (ELS) are rare, and it is quite challenging to differentiate between an adenoma and an adenocarcinoma. ELS tumors (ELST) usually present with papillary, follicular, or solid patterns and can be further distinguished histologically and through immunohistochemistry. The microscopic features and clinical course of this neoplasm have been comprehensively explained by Heffner, who considered it "low-grade adenocarcinoma of likely ELS origin." The papillary form more commonly affects females, and it is a more aggressive form of ELST that is destructive and exhibits extensive local spread. The tumor usually has a close association with von Hippel-Lindau (VHL) disease, but 11%-30% of the ELST cases develop in individuals without a VHL mutation. ELSTs manifest with headaches, hearing loss, ear discharge, and cranial nerve palsies. Currently, the only available curative therapeutic intervention consists of wide local excision and long-term follow-up. Because of the sensitive location of this tumor, the adjuvant radiotherapy options are still questionable. In this case report, the author presents a 74-year-old woman with a past medical history of Schneiderian papilloma and was diagnosed with papillary mucinous adenocarcinoma of the ELS not associated with VHL disease.

[Endolymphatic sac tumor with symptoms of endolymphatic hydrops: a case report and reviews].

A 38-year-old woman had suffered from recurrent vertigo, deafness and tinnitus for 2 years. After treatment for Meniere's disease, her symptoms did not improve. The threshold of pure tone audiometry was 68dBHL SNHL. High resolution CT of the temporal bone showed that a mass is behind the posterior semicircular canal. MRI showed that mixed signals are in the center of the mass and long T1T2 signal around the mass. The mass was surgically resected. Pathology report showed: endolymphatic sac tumor.

Long experience for the diagnosis and treatment of sporadic endolymphatic sac tumor in a single center.

OBJECTIVES: Sporadic endolymphatic sac tumor (ELST) is rare. The purpose of this study was to analyze the clinical feature and surgical outcome of a single-center series of sporadic ELSTs. PATIENTS AND METHODS: We retrospectively reviewed all cases of sporadic ELSTs operated at the Tiantan hospital between 2010 and 2020. RESULTS: Retrospective record revealed 14 patients with sporadic ELSTs who underwent surgical management. Serum VEGF(vascular endothelial growth factor)values of 6 patients were measured on admission, and the levels were all higher than normal(0-160 ng/L, Enzyme-Linked ImmunoSorbent Assay). All patients underwent surgical treatments, and there was no significant difference in KPS before and after the operation(KPS = 88:88). The average maximum diameter of the tumor was 41 mm (range28-56 mm). After surgery, Two patients received radiation therapy, We did not encounter any case with metastatic dissemination. No deaths occurred during follow-up. CONCLUSION: ELST is defined as an aggressive or low-grade malignant tumor, with the characteristics of local recurrence and invasion of bone growth. Sporadic cases are common, and this rare tumor provides insight into the relationship between ELST and VHL syndrome. Early surgical resection can prevent or reduce the disability of auditory vestibular symptoms, and improve the chance of complete resection and retention of hearing. As far as possible complete resection of the tumor can prolong the disease-free survival of patients. Preoperative radiotherapy or stereotactic therapy cannot control tumor growth. Postoperative radiotherapy may have a positive effect on tumor control. The high expression of VEGF in patients may be related to tumor occurrence and development.

Fibrous dysplasia mimicking a pediatric endolymphatic sac tumor.

A 15-year-old female presented for evaluation of progressive hearing loss over a year. Computed tomographic imaging revealed a 11 x 6 × 6 mm osseous lesion with 'groundglass' appearance within the left posterior petrous bone lateral to vestibular aqueduct suspicious for an endolymphatic sac tumor. Surgical excision revealed fibrous dysplasia on histological analysis. Fibrous dysplasia of the temporal bone is not uncommon, but few cases of extension causing sensorineural hearing loss exist in the literature. We describe the first reported case of fibrous dysplasia mimicking an endolymphatic sac tumor; interestingly, the patient also showed hearing improvement immediately following removal.

Endolymphatic sac tumor: case report and literature review.

BACKGROUND: Endolymphatic sac tumor (ELST) is one of neuroectodermal tumor which arising from endolymphatic sac and duct. It is actually quite rare, with less than 200 cases reported. Although ELST presents benign appearance in histopathology, it can present aggressive destructive behavior in clinical. The cornerstone of treatment for ELST is complete surgical excision. However, it is almost impossible to completely resect the advanced stage tumor. There is still controversy about other treatments, such as radiotherapy and gamma knife surgery. CASE PRESENTATION: A 47-year-old man was admitted in The First Affiliated Hospital of Fujian Medical University with a 7-year history of progressive hearing loss and near 6-month repeated attacks of headache. Preoperative CT revealed a massive intracranial lesion and associated hydrocephalus. MR scanning demonstrated a 7.2 cm × 4.6 cm × 4.2 cm bulky mass located in left-sided posterior cranial fossa and temporo-occipital region which showed hyperintensity on T1-weighted images and mixed signal intensity on T2-weighted images. There was no neither clinical manifestation nor family history of Von Hippel-Lindau syndrome (VHL).Due to the mass that was large and invading the bone of skull base, it was difficult to extirpate surgically, so the ventriculoperitoneal shunt combined with local biopsy was performed. The postoperative pathology and immunohistochemical findings confirmed the lesion was an endolymphatic sac tumor. After operation, the patient regularly received radiotherapy. CONCLUSION: The widely accepted management of ELST is complete surgical resection. However, it is difficult for surgeons to achieve radical resection with late-stage ELST. Currently, there is much dispute about the role of radiotherapy for the management of ELST in academic circles. In this case where the mass cannot be surgical removed, radiotherapy has the curative effect for ELST in terms of disease control and quality of life.