Endolymphatic sac tumor misdiagnosed as metastatic renal cell carcinoma: Pitfalls in morphology and immunohistochemistry.

Endolymphatic sac tumor (ELST) is a rare disease that originates from the endolymphatic sac system of the inner ear. Being a low-grade malignant tumor, ELST has a mild morphology and is characterized by a slow but aggressive growth. Most clinicians and pathologists are unfamiliar with this disease. ELST can be misdiagnosed as metastatic renal cancer because of the similarity in morphology and expression of nephrogenic markers such as PAX8. The presented case of a 27-year-old man revealed that observing the characteristic location and confirming the absence of renal neoplasm to rule out the possibility of metastasis are critical for obtaining an accurate final diagnosis.

Functional outcomes and caloric response changes after endolymphatic sac decompression.

OBJECTIVE: To evaluate caloric response changes after endolymphatic sac decompression (ESD), together with hearing outcomes and the functional benefit of the operation. METHODS: A retrospective chart review of subjects who underwent endolymphatic sac decompression at a tertiary referral centre was performed. Data on audiological results, caloric testing, and functional level scale of the patients were analysed. RESULTS: Twenty-eight patients who met our criteria were eligible for enrolment in the study. The average follow-up after surgery was 25 months (range, 13-41). Postoperative pure-tone threshold averages and reduced vestibular response values (RVR) were not significantly altered by ESD; whereas, functional level scores improved significantly. CONCLUSION: Endolymphatic sac decompression is a surgical procedure that preserves hearing and vestibular function, and improves the daily functional level of patients with Ménière's disease. ESD can be preferred both in bilateral and unilateral disease because it does not alter vestibular function and preserves hearing.

Occlusion of the Lateral Semicircular Canal, Endolymphatic Sac Surgery, and Cochlear Implantation: A Low Destructive Treatment for Unilateral Ménière's Disease and Deafness.

INTRODUCTION: Surgical treatment of Ménière's disease (MD) and deafness aims to treat vertigo and hearing disabilities. Current treatment options like labyrinthectomy and cochlear implantation (CI) have shown acceptable results but are destructive. Less destructive procedures, like the occlusion of the lateral semicircular canal and endolymphatic sac surgery, have been shown to be successful in vertigo control. The combination of both procedures with CI has not been investigated; therefore the objective of this study was to investigate the outcome of this combination in patients with single-sided MD and moderately severe to complete sensorineural hearing loss. METHODS: In this retrospective study, 10 patients with single-sided MD and moderately severe to complete sensorineural hearing loss were included. In all of them, a single-staged surgery, which consisted of CI, endolymphatic sac surgery, and occlusion of the lateral semicircular canal, was performed. The surgery was performed after a failed conservative therapy trial. The clinical outcome was evaluated by the Dizziness Handicap Inventory (DHI) and audiological tests. These were assessed preoperatively, 3 and 6 months after surgery. An MRI with a hydrops sequence was performed to support the clinical diagnosis. RESULTS: After the combined surgery, the mean DHI testing improved significantly from 71 to 30. Mean audiological monosyllabic speech testing outcome with the cochlea implant was 65% at 65 dB. The residual hearing of 2 patients could be preserved after the surgical procedure. CONCLUSION: The combination of occlusion of the lateral semicircular canal, endolymphatic sac surgery, and CI is an efficient low traumatic treatment for patients with a single-sided MD and moderately severe to complete sensorineural hearing loss.

Significance of endolymphatic sac surgery with and/or without simultaneous cochlea implant surgery in respect of vertigo control and speech perception in patients with Menière's disease.

PURPOSE: The focus on treating patients with Menière's Disease (MD) lies on the reduction of vertigo attacks and the preservation of sensory function. Endolympathic hydrops is considered as an epiphenomenon in MD, which can potentially be altered by endolymphatic sac surgery (ESS). Purpose of the study was to investigate the influences on vertigo control through manipulation of the perilymphatic system with or without ESS. METHODS: Retrospective data analysis of 86 consecutive patients with MD according to current diagnostic criteria after endolymphatic sac surgery alone (ESSalone; n = 45), cochlear implantation (CI) alone (CIalone; n = 12), and ESS with CI (ESS + CI; n = 29), treated at a tertiary referral center. MAIN OUTCOME MEASURES: vertigo control, speech perception pre- and postoperatively. RESULTS: Gender, side, and preoperative treatment were similar in all groups. Age was younger in the ESSalone-group with 56.2 ± 13.0 years (CIalone = 64.2 ± 11.4 years; ESS + CI = 63.1 ± 9.7 years). Definitive MD was present in all the CIalone, in 79.3% of the ESS + CI and in 59.6% of the ESSalone-patients. Likewise, vertigo control rate was 100% in the CIalone, 89.7% in the ESS + CI and 66.0% in the ESSalone-group. CONCLUSIONS: Vertigo control was improved in all three groups, however, superior in groups treated with CI, potentially contributed by the manipulation of both the endo- and perilymphatic systems. A more systematic characterization of the patients with larger case numbers and documentation of follow up data would be needed to evaluate a clinical effect more properly.

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.

Development and validation of prediction model to estimate vertigo risk after endolymphatic sac decompression in Meniere's disease: a retrospective cohort study.

PURPOSE: To study the efficacy predictors of endolymphatic sac decompression (ESD) in Meniere's disease (MD), and to establish and verify the prediction model of vertigo after ESD in patients with MD. METHODS: The retrospective cohort data of 56 patients with unilateral MD who underwent ESD surgery were recorded. A stepwise regression method was used to select optimal modeling variables, and we established a logistic regression model with the outcome of vertigo after ESD. The bootstrap method was used for internal validation. RESULTS: Potential predictors included sex, age, follow-up duration, disease course, attack duration, frequency of attack, pure-tone threshold average (PTA) of the patient's speech frequency, audiogram type, glycerin test results, MD subtype, and 10-year atherosclerotic cardiovascular disease risk classification. Using the stepwise regression method, we found that the optimal modeling variables were the audiogram type and PTA of the patient's speech frequency. The prediction model based on these two variables exhibited good discrimination [area under the receiver operating characteristic curve: 0.72 (95% confidence interval: 0.57-0.86)] and acceptable calibration (Brier score 0.21). CONCLUSION: The present model based on the audiogram type and PTA of the patient's speech frequency was found to be useful in guidance of ESD efficacy prediction and surgery selection.

Endolymphatic Duct and Sac Decompression: A New Life for an Old Technique.

BACKGROUND: Ménière's disease is an inner ear disorder causing recurrent vertigo, hearing loss, and tinnitus. Diagnosis is based on the variability of the symptoms over time and absence of radiological abnormalities. Medical therapy is effective only in a small percentage of patients. Surgical strategies remain controversial. In this article, we revisit a surgical technique neglected over the years: endolymphatic sac surgery. METHODS: Fifty-four patients affected by Ménière's disease underwent endolymphatic duct and sac decompression. According to the American Academy of Otolaryngology-Head and Neck Surgery criteria, vertigo control was evaluated with follow-up at 6 months, 1 year, and 2 years from the intervention. Hearing results were evaluated before the surgery and at 2 years of follow-up using the pure tone average. The results were compared with similar techniques of endolymphatic sac surgery described in the literature. RESULTS: According to the American Academy of Otolaryngology-Head and Neck Surgery criteria classification, 2 years after surgery, 87% patients achieved complete control of vertigo (class A). The hearing remained stable in 93.5% of patients. The results appear compatible with other publications data regarding endolymphatic sac surgeries. CONCLUSION: The duct and endolymphatic sac decompression allows the control of vertigo and preserves hearing from the pathological effects of Ménière's disease. The revised technique allows the functional restoration of endolymphatic homeostasis.

Surgical Treatment of an Endolymphatic Sac Tumor.

Endolymphatic sac tumors (ELST) are low-grade papillary adenocarcinoma originating from the endolymphatic sac. Usually slow-growing, with local aggressiveness and a low risk of distant metastases, ELST can be sporadic but also frequently associated with von Hippel Lindau disease. The current treatment of ELST is primarily surgical resection. A 55-year-old woman accessed our otologic tertiary level referral center for a sudden worsening of hearing loss in her left ear and vertigo. A magnetic resonance (MRI) and computer tomography scan study subsequently showed a mass in the petrous bone; hence, the presence of an ELST was hypothesized. After embolization of the mass, the patient underwent surgical removal of the lesion. The resection of the mass was done through a translabirinthine approach, with an uneventful procedure. No residual disease remained after surgery. After 24 months of radiologic follow up with MRI, there are no signs of recurrence disease. This paper reports the management of this sporadic ELST, as well as the follow up results, providing clinicians this protocol for the handling of such a challenging otologic skull base surgery and rare disease.

Surgical Management of Endolymphatic Sac Tumor: A Systematic Review and Meta-Analysis.

The aim of our study was to report rates of facial nerve palsy and residual tumor following surgical intervention and subsequent tumor recurrence in patients with endolymphatic sac tumors. A systematic literature review of preoperative assessment and surgical management is also included. Studies including patient/s affected by sporadic or von Hippel-Lindau disease related endolymphatic sac tumors, reporting levels of facial nerve function, residual and recurrence pathology following a surgical procedure, were considered. Data were combined for proportional meta-analysis, and the selected studies' methodological quality was also evaluated. Overall 34 papers, including 202 subjects (209 cases of endolymphatic sac tumors) were analyzed. Pooled proportion rate (95% CI) of overall facial nerve palsy was 39.7% (28.2-51.9) and residual tumor was 16.5% (10.3-23.7) after surgical procedure. Pooled proportion rate (95% CI) of tumor recurrence was 14.0% (9.7-19.3) during a mean follow-up period of 49.7 months (8-136). Our results showed that preoperative facial nerve function is impaired in almost 30% of patients with endolymphatic sac tumors. Surgical management of endolymphatic sac tumor may cause a worsening of facial nerve function in a low percentage of treated subjects. Residual and/or recurrence of endolymphatic sac tumors are not rare events, and follow-up strategies should be designed accordingly.

Endolymphatic Duct Blockage as a Surgical Treatment Option for Ménière's Disease.

Endolymphatic duct blockage is a relatively new treatment option for Ménière's disease, aiming to reduce vertigo attacks while sparing hearing and equilibrium. After a regular mastoidectomy, the posterior semicircular canal is identified, and Donaldson's line is determined. This is a line through the horizontal semicircular canal, crossing the posterior semicircular canal. The endolymphatic sac is usually found at this site under the posterior semicircular canal. The bone of the endolymphatic sac and the dura are thinned until the sac is skeletonized, after which the endolymphatic duct is identified. The duct is then blocked with a titanium clip. Using a computerized tomography (CT) scan, the position is confirmed. Follow-up visits take place 1 week, 6 weeks and 1 year after surgery. To this day, only one prospective trial assessing this method has been conducted, comparing this new method to endolymphatic sac decompression. Results of the duct blockage are promising, with 96.5% of the patients free of vertigo after 2 years. However, further research is required.

[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.

Endolymphatic sac tumour - a rare complication associated with von Hippel-Lindau disease.

We report the case of a 42-year - old female with familiar form von Hippel-Lindau disease (VHL) and recurrent endolymphatic sac tumour (ELST), which was presented like non-homogenous, solid and cystic expansion of the left petrous temporal bone. Histologically, there was found lamellae of bone with adjacent ligament and with papillary projections with fibrovascular core. The papillae were lined by a single layer of cuboidal epithelium with hyperchromatic and lightly pleomorphic nuclei. Sporadically, small cystic formations with eosinophilic, PAS positive secretion were noted. Imunohistochemically, the cuboidal cells showed diffuse positivity for vimentin, epithelial membrane antigen (EMA), cytokeratin AE1/AE3 and S100 protein (weakly). Other markers examined, including TTF1, PAX8 and CD10, were negative. Endolymphatic sac tumour is rare low-grade malignant epithelial tumour arising from the endolymphatic sac in the temporal bone, which occurs in 1 out of 30 000 births, with just fewer than 300 cases reported in the literature. About one third of cases are associated with von Hippel- Lindau disease, an autosomal dominant familial cancer syndrome.

Evaluation of changes in endolymphatic volume after middle ear pressure therapy for intractable meniere's disease using 3D magnetic resonance imaging.

BACKGROUND: Nowadays, the endolymphatic space size can be evaluated by 3D-analysis of 3 T-MRI after intravenous injection of gadolinium enhancement. AIMS/OBJECTIVES: In the present study, to elucidate the relationships between vertigo and endolymphatic hydrops (EH) volume after middle ear pressure therapy (MEPT), we investigated changes in EH volume after MEPT for intractable Meniere's disease (MD) by means of the inner ear MRI (ieMRI) in relation to clinical results. MATERIALS AND METHODS: We enrolled 202 successive definite MD cases with intractable vertiginous symptoms from 2015 to 2020, assigning Group-I of MEPT, and Group-II of endolymphatic sac drainage (ELSD). Ninety patients completed the planned 2-year-follow-up, which included assessment of vertigo frequency and changes in EH volume using ieMRI (Group-I/MEPT: n = 40; Group-II/ELSD: n = 50). RESULTS: Two years after surgery, vertigo was completely controlled in 77.5% of patients in Group-I and 90.0% in Group-II. Hearing improved by >10 dB in 7.5% of patients in Group-I and 24.0% in Group-II. ELS ratios were significantly reduced after treatments of Group-I and Group-II only in the vestibule. CONCLUSIONS: The obtained results indicate that MEPT as well as ELSD could be a good treatment option for patients with intractable MD.

The Diagnosis and Management of Advanced Endolymphatic Sac Tumor.

Endolymphatic sac tumor (ELST) is a group of low-grade malignant tumors originating from the endolymphatic sac of the inner ear. It is rare in the clinic and has the biological characteristics of slow growth and local aggression. Due to the lack of specificity in the clinical manifestations of patients with ELST, many cases have entered the advanced stage at the time of diagnosis. However, there are still great challenges in the treatment of advanced ELSTs. Here, the authors describe a case of advanced ELST, which relapsed after 2 operations. This time, the authors chose the transotic approach for tumor resection, which achieved the goal of complete resection of the tumor, and the patient recovered smoothly after surgery. There were no surgical complications and no tumor recurrence after the follow-up. Through literature review and our own experience, the authors suggest that complete surgical resection is the first choice for both primary and recurrent advanced ELSTs. The choice of a reasonable surgical approach is the key to ensuring complete resection of the tumor, while preoperative angiography and embolization, fine treatment of important structures during surgery, and postoperative long-term follow-up are equally important for patients with advanced ELST to obtain a good prognosis.

Endolymphatic sac decompression effect on secondary symptoms of Meniere's disease.

OBJECTIVE: To evaluate if endolymphatic sac decompression (ESD) significantly improves secondary symptoms of Meniere's disease including tinnitus and aural fullness. STUDY DESIGN: Survey study with retrospective chart review. SETTING: Tertiary care center. METHODS: Survey of adult patients with Meniere's disease that underwent primary ESD surgery from 2015 to 2020. Subjective reporting of pre- and postoperative aural fullness and tinnitus based on postoperative survey. Survey results and audiologic data of the patients that reported were compared pre- and postoperatively. RESULTS: Statistical analysis was performed using weighted kappa statistics to examine the level of agreement. There was a value of 0.12 for pre- and postoperative aural fullness, indicating a difference in the two groups with 77 % having improvement and only 4 % having worsening. There was a value of 0.21 for pre- and postoperative tinnitus, demonstrating a lack of agreement with 58 % having improvement and 4 % having worsening. Overall, there was significant improvement in both tinnitus and aural fullness postoperatively. There was no significant difference in word recognition score, speech reception threshold, or pure tone average between the pre- and postoperative group based on paired t-test. CONCLUSIONS: There is a significant improvement in both aural fullness and tinnitus for patients undergoing ESD with no negative effect on audiologic status. ESD is a viable option for treatment of Meniere's disease with vertigo, aural fullness, and tinnitus relief. Future prospective studies are needed to further improve the evidence of ESD's effect on secondary symptoms of Meniere's disease.

Untargeted Metabolomic Analysis in Endolymphatic Sac Luminal Fluid from Patients with Meniere's Disease.

Dysfunction of the endolymphatic sac (ES) is one of the etiologies of Meniere's disease (MD), the mechanism of which remains unclear. The aim of the present study was to explore the molecular pathological characteristics of ES during the development of MD. Metabolomic profiling of ES luminal fluid from patients with MD and patients with acoustic neuroma (AN) was performed. Diluted ES luminal fluid (ELF) samples were obtained from 10 patients who underwent endolymphatic duct blockage for the treatment of intractable MD and from 6 patients who underwent translabyrinthine surgery for AN. ELF analysis was performed using liquid chromatography-mass spectrometry before the raw data were normalized and subjected to subsequent statistical analysis by MetaboAnalyst. Using thresholds of P ≤ 0.05 and variable important in projection > 1, a total of 111 differential metabolites were screened in the ELF, including 52 metabolites in negative mode and 59 in positive mode. Furthermore, 15 differentially altered metabolites corresponding to 15 compound names were identified using a Student's t-test, including 7 significant increased metabolites and 8 significant decreased metabolites. Moreover, two differentially altered metabolites, hyaluronic acid (HA) and 4-hydroxynonenal (4-HNE), were validated to be upregulated in the epithelial lining of the ES, as well as in the subepithelial connective-tissue in patients with MD comparing with that in patients with AN. Among these differentially altered metabolites, an upregulated expression of HA detected in the ES lumen of the patients with MD was supposed to be associated with the increased endolymph in ES, while an increased level of 4-HNE found in the ELF of the patients with MD provided direct evidence to support that oxidative damage and inflammatory lesions underlie the mechanism of MD. Furthermore, citrate and ethylenediaminetetraacetic acid were detected to be decreased substantially in the ELF of the patients with MD, suggesting the elevated endolymphatic Ca2+ in the ears with chronic endolymphatic hydrops is likely to be associated with the reduction of these two chelators of Ca2+ in ES. The results in the present study indicate metabolomic analysis in the ELF of the patients with MD can potentially improve our understanding on the molecular pathophysiological mechanism in the ES during the development of MD.

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.