Evaluation and Management of Endolymphatic Sac and Duct Tumors

Grading system and surgical approaches for endolymphatic sac tumors

PURPOSE

Endolymphatic sac tumors (ELSTs) are rare, low-grade adenocarcinomas arising from the endolymphatic sac. This study aims to present a novel grading system for ELSTs to determine the optimal management strategy.

METHODS

We performed a retrospective analysis of 16 patients with 17 ELSTs. The tumor location and involved adjacent neurovascular structures on CT and MRI were selected to establish the grading system.

RESULTS

Based on the novel grading system, grade III a tumors were most common (7/17), followed by grade I (4/17), grade II (3/17), and grade III b (3/17) tumors. Eight advanced ELSTs (grade III a and III b) received an infra-temporal fossa approach, while the other 6 early stage ELSTs (grade I and II) underwent either a retrolabyrinthine approach with posterior petrosectomy or a translabyrinthine approach combined with subtotal temporal bone resection. Hearing preservation was achieved in 2 grade I patients. Postoperative facial nerve function was HB II in 1 grade III a patient who underwent anterior facial nerve transposition and was HB III in 4 advanced patients who received facial nerve grafts with the great auricular nerve or facial-hypoglossal nerve anastomosis. The mean follow-up time was 35.1 months. Two grade III patients and 1 grade II patient had tumor recurrence during follow-up, among whom 1 grade III b patient had two cases of recurrence.

CONCLUSION

A correct initial diagnosis was established in all patients after meticulous imaging studies. Surgical resection is still the first choice to manage patients with ELSTs. The novel grading system enables surgeons to select tailored surgical approaches. Long-term follow-up is necessary following surgical intervention.

Radiotherapy and Radiosurgery for Treatment of Residual or Recurrent Endolymphatic Sac Tumor Following Previous Microsurgical Resection

OBJECTIVE

To report and discuss the effectiveness of stereotactic radiosurgery (SRS) or fractionated radiotherapy (FRT) for tumor control following surgical resection of endolymphatic sac tumors (ELST).

STUDY DESIGN

Retrospective case series.

SETTING

Multi-institutional academic referral centers.

PATIENTS

Patients undergoing surgical resection for ELST followed by SRS or FRT.

INTERVENTION(S)

Surgical resection followed by radiotherapy.

MAIN OUTCOME MEASURES

Local tumor control.

RESULTS

Two of the five patients experienced tumor recurrence after gross total microsurgical at 78 and 11 months, respectively. The former patient received salvage 3D conformal radiotherapy (3D-CRT) and while the latter patient underwent three courses of salvage SRS for recurrence, two of which were in-field and was disease-free at last follow up. Two additional patients underwent subtotal tumor resection (STR) followed by intensity-modulated radiation therapy (IMRT) and are currently without disease. One patient underwent STR followed by proton-beam therapy (PBT) and was free of disease at most recent follow-up.

CONCLUSION

SRS/FRT remains a useful adjuvant for treatment of residual or recurrent ELSTs, where the risk of revision microsurgical resection is high.

Transcanal endoscopic assisted skull base endolymphatic sac tumor resection: A rare disease with advanced technology

Endolymphatic sac tumors (ELSTs) are rare, papillary adenomatous tumors that arise from the endothelium of the endolymphatic sac. We demonstrate a difficult case of endolymphatic sac tumor and how it is managed via transcanal endoscopic assisted technique, with discussion of feasibility of transcanal approach to lateral skull base tumor.

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%.

Atypical radiographic features of skull base cholesterol granuloma

Cholesterol granulomas (CGs) are the most common benign lesions of the petrous apex (PA) and have distinct computed tomography (CT) and magnetic resonance imaging (MRI) characteristics. On CT, CGs of the PA (PACG) present as expansile lesions with erosion of bony trabeculae. MRI shows a hyperintense lesion on T1-and T2-weighted images and do not enhance with gadolinium. The objective is to describe the radiographic features of CGs of the skull base that do not arise from the PA. This study is a retrospective review. Three patients were operated on for suspected recurrent endolymphatic sac tumor, intracranial cholesteatoma, and recurrent sphenoid wing meningioma based on CT and MRI findings. Pathology results were consistent with CG in all three cases. All patients had bone erosion on CT. These skull base CGs did not demonstrate similar MRI features. These lesions were hyperintense, iso-to-hyperintense, and hypointense on T1-weighted MRI, respectively. These CGs were hyperintense in two cases and iso-to-hyperintense in one case on T2-weighted MRI. These lesions either demonstrated central or rim enhancement after gadolinium administration. Skull base CGs that do not arise from the PA demonstrate a broad spectrum of radiographic characteristics on MRI that are not typical of PACG.

Endolymphatic sac tumors

Endolymphatic sac tumors (ELST) are slow-growing, locally aggressive, low-grade malignancies that originate from the epithelium of the endolymphatic duct and sac. ELST often present with sensorineural hearing loss, tinnitus, and vertigo, which may mimic Meniere disease. Large tumors may present with additional cranial neuropathies. Management is primarily via microsurgical excision. Radiation therapy has a limited role for residual or unresectable disease. Early detection may enable hearing preservation techniques. ELST have an association with von Hippel-Lindau disease.

An endolymphatic sac tumor with imaging features of aneurysmal bone cysts: differential diagnostic considerations

BACKGROUND

Endolymphatic sac tumors (ELSTs) are rare, slow-growing tumors of the petrous bone. Despite the typical localisation, their radiological diagnosis can be challenging due to the variety of other tumors potentially showing similar features.

CASE REPORT

We present a 16-year-old child with progressive hearing loss, vertigo, and tinnitus who had a large petrous bone lesion showing imaging features of both ELSTs and aneurysmal bone cysts (ABCs). The patient underwent preoperative embolization of the tumor-supplying vessels and subsequently a subtotal resection. Histological examination revealed an ELST.

CONCLUSION

Despite the rarity of petrous bone ABCs, they should be considered as a differential diagnostic alternative of ELSTs due to their similar imaging appearance.

A rare case of endolymphatic sac tumour: clinicopathologic study and surgical management

Objective. Endolymphatic sac tumor (ELST) is a rare neoplasm arising from the intrapetrous portion of the endolymphatic sac, either isolated or in association with the von Hippel-Lindau disease. We report a sporadic case of ELST with an overview of the literature and a discussion of clinic-radiological, histopathologic, and surgical findings. Case Report. A young woman presented with a progressive hearing loss in the left ear. Otoscopy showed a reddish, bleeding hypotympanic mass. CT demonstrated an expansile lytic mastoid lesion extending to the middle ear, with bone erosion. MRI confirmed a lesion of increased signal on T1-weighted sequences. The patient underwent a canal wall-down tympanoplasty with complete removal of the tumor. Histopathology was consistent with a papillary ELST. Immunohistochemistry was positive for cytokeratin and chromogranin A. Conclusion. This paper highlights the rarity of ELST, the need for an accurate neuroradiological and immunohistochemical study at the early stages, and the timeliness of surgical treatment.

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

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

Contemporary perspectives on the pathophysiology of Meniere's disease: implications for treatment

PURPOSE OF REVIEW

Meniere's disease is characterized by episodic vertigo, fluctuating hearing loss, aural fullness and tinnitus. Endolymphatic hydrops, found on post-mortem examination, is the histologic hallmark. Recent research suggests that endolymphatic hydrops results from cytochemical perturbations of unknown etiology that lead to disturbance of the normal endolymphatic fluid homeostasis. This consequent hydropic state or the associated cytochemical perturbations appears to create a neurotoxic environment that ultimately leads to spiral ganglion cell death likely via the apoptotic mechanism. This review highlights some of the recent advances in the understanding of the pathophysiology of endolymphatic hydrops and progressive cochleovestibular deterioration, with emphasis placed on its potential therapeutic implications.

RECENT FINDINGS

Recent evidence supports that endolymphatic hydrops is possibly an epiphenomenon, and is preceded by perturbation of the normal ionic transport regulatory mechanisms. Furthermore, chronic cochleovestibular deterioration appears to be the result of an excitotoxic response to chronic hydrops. A recently described animal model, the Phex mouse, carrying a mutation in the Phex Hyp-Duk gene, provides a novel insight to genetically regulated postnatal endolymphatic hydrops and a useful tool to expand our understanding.

SUMMARY

Despite encouraging recent advances, there are considerable challenges that remain in the development of targeted therapeutic interventions that may offer new avenues of neuroprotection in known cases of Meniere's disease. These advances will hopefully provide pharmacotherapeutic interventions aimed at preventing progressive cochleovestibular dysfunction.

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.