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.     

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.     

Endolymphatic sac carcinoma of the right petrous bone in Von Hippel-Lindau disease.

A large endolymphatic sac papillary adenocarcinoma in a patient with Von Hippel-Lindau (vHL) disease is reported. A 31-year-old man was treated for a left eye retinal angioma 10 years previously and had been blind in that eye since. He was admitted with progressive tinnitus, lower cranial nerve paresis and ataxia. Investigations revealed a vascular and bone-eroding petrous tumour. The entirely extradural tumour involved a large part of the petrous bone and extended into the cerebellopontine angle. The vascular tumour was radically resected using a presigmoid approach after feeding vessel embolisation. The literature on this rare clinical entity is briefly discussed.     

Endolymphatic sac tumor: staged endovascular-neurosurgical approach

Endolymphatic sac tumors are rare, low-grade adenocarcinomas of the petrous bone. These tumors are highly vascularized and surgical removal is often challenging. We present a staged endovascular-neurosurgical approach consisting of stent-assisted angioplasty of the petrous carotid, selective endovascular embolization and surgical removal.     

Piezosurgery for safe and efficient petrous bone cutting in cerebellopontine angle and petroclival meningioma surgery

Intradural petrous bone drilling has become a widespread practice, providing extended exposure in the removal of cerebellopontine angle (CPA) or petroclival tumors. Adjacent neurovascular structures are at risk, however, when drilling is performed in this deep and narrow area. Hence, this study evaluates the use of Piezosurgery (PS) as a non-rotating tool for selective bone cutting in CPA surgery.A Piezosurgery® device was used in 36 patients who underwent microsurgery for extra-axial CPA or petroclival tumors in our Neurosurgical Department between 2013 and 2019. The clinical and radiological data were retrospectively analyzed. The use of PS was evaluated with respect to the intraoperative applicability and limitations as well as efficacy and safety of the procedure.Piezosurgical petrous bone cutting was successfully performed in the removal of meningiomas or extra-axial metastases arising from the dura of the petroclival region (21 patients) or petrous bone (15 patients). PS proved to be very helpful in the deep and narrow CPA region, considerably reducing the surgeon’s distress toward bone removal in close proximity to cranial nerves and vessels in comparison to common rotating drills. The use of PS was safe without injuries to neurovascular structures. Gross total resection was achieved in 67% of petroclival and 100% of petrous bone tumors.Piezosurgery proved to be an effective and safe method for selective petrous bone cutting in CPA surgery avoiding rotating power and associated risks. This technique can particularly be recommended for bone cutting in close vicinity to critical neurovascular structures.     

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.     

Cerebellopontine angle subependymoma without fourth ventricle extension: An uncommon tumor in a rare location

Subependymomas are benign tumors that occur predominantly in the ventricular system. We describe a case of a 57‐year‐old man with a large cerebellopontine angle (CPA) tumor which expanded into the jugular foramen. Complete surgical excision of the tumor was achieved through a retrosigmoid approach and the histopathological diagnosis was subependymoma. Subependymomas located exclusively in the CPA without extension into the fourth ventricle are extremely rare. The mainly pathological features and the difficulty in correctly diagnosing these cases preoperatively, even with MRI, are discussed.     

Petroclival intravascular papillary endothelial hyperplasia with psammoma body-like structures

Masson's tumor or intravascular papillary endothelial hyperplasia (IPEH) is considered a non-neoplastic lesion. It is probably an unusual exaggerated reorganization of a thrombus. IPEH may be present as a secondary lesion in hemangiomas. Symptomatic osseous hemangiomas are rare tumors. Few cases of clival and petrous bone hemangiomas have been described. None of them shows secondary IPEH. So far, there are only four reported cases of cranial bone IPEHs in the literature, two in the skull, one in the clivus and one in the petrous apex. The aim of this study is to report an additional case of osseous hemangioma with secondary IPEH of the petroclival region. We review the literature and describe the main clinical features of IPEHs and hemangiomas of the clivus and the petrous bone. Additionally, we report an unusual histological feature observed in our case of IPEH, the presence of psammoma body-like structures. This feature has been rarely mentioned previously in IPEH. We consider that IPEH should be included in the lesions that may present psammoma bodies to avoid misdiagnosing it as a tumor that commonly shows psammoma bodies, such as intraosseous meningioma or, less frequently, metastasis of thyroid or ovarian carcinoma.     

经岩骨乙状窦前入路处理岩斜区肿瘤(附40例报告)

目的提高经岩骨乙状窦前入路处理岩斜区肿瘤的手术疗效.方法对采用经岩骨乙状窦前入路处理的40例岩斜区肿瘤病人的临床特征、手术方法、手术结果及术后并发症进行回顾性分析.以岩骨乙状窦交叉点和内淋巴囊裂作为磨除岩骨的定位标志,以减少岩骨内结构的损伤.结果肿瘤全切除27例,次全切除9例,部分切除4例.无手术死亡.术后主要并发症为脑神经损伤、脑组织水肿、肌力减退等.结论经岩骨乙状窦前入路是处理岩斜区肿瘤较好的手术方法.大多可全切除肿瘤.     

Endolymphatic sac adenocarcinoma: case report

A case of endolymphatic sac adenocarcinoma is reported and the literature is reviewed. The clinical picture was presented by vertigo and progressive hearing loss caused by a tumor of the endolymphatic sac. The surgical removal was complete, via a retro and translabyrinthine approach. Endolymphatic sac tumors are locally invasive, involve the petrous bone and the mastoid. The radical surgery presents good outcome.     

小脑桥脑角髓母细胞瘤延伸至幕上区的成年个案

髓母细胞瘤是一种罕见的中枢神经系统肿瘤,甚至在成年期发生罕见。它可能发展为一个像小脑桥脑角肿瘤,而这些非典型和不常见的网站可能很少目前与前天幕延伸。我们报告从桥小脑幕上区延伸到成人髓母细胞瘤角案件。病人提出的投诉与头痛,眩晕,听力在左听,恶心/呕吐,步态不稳的困难。失衡已经从4周前。关于考试,他的脑神经检查是正常的。电脑断层扫描显示高密度病灶,异质性增强的左侧小脑桥脑角区群众。他是经营上的注册会计师地区大部切除病灶。髓母细胞瘤的组织病理学检查证实,世卫组织第四级。手术后,他接受放射治疗。他得到了改善,而且还为31个月无症状。他重新操作两个髓母细胞瘤复发及恶化更多的时间和最终死亡。肿瘤表现为前天幕延伸,使这种情况在后颅窝的位置比其他参与的独特的小脑桥脑角的参与。磁共振成像被认为是很为这个罕见的肿瘤类型的管理。     

Gamma knife radiosurgery in jugular foramen endolymphatic sac adenocarcinoma

A 41-year-old male presented to us with a history of right-sided temporal headache and ear discharge. MRI revealed an extra-axial space-occupying lesion in the region of the right jugular foramen. The patient was operated upon and a radical excision of the tumor was performed. Histopathology revealed an adenocarcinoma, probably of endolymphatic sac origin. The patient had a recurrence of tumor at 2-year follow-up and was subjected to gamma knife radiosurgery. The patient was subsequently asymptomatic at a 2.5-year follow-up and imaging revealed regression of the tumor size. Stereotactic radiosurgery in recurrent endolymphatic sac tumors involving the jugular foramen has not been reported previously. We review the literature on this novel treatment protocol for this rare skull base tumor.     

Simultaneously occurring vestibular schwannoma and meningioma in the cerebellopontine angle: case report and literature review

Simultaneously occurring multiple primary brain tumors of different histological types are rare, and the coexistence of schwannoma and meningioma in the same cerebellopontine angle (CPA) without neurofibromatosis is extremely rare. A 57-year-old female patient presented with headache, speech disturbance, left facial numbness and deafness in the left ear. Magnetic resonance imaging demonstrated two different tumors in the left CPA. These tumors were not in continuity. The tumors were totally removed through the left suboccipital approach. Histopathological examination revealed that the large tumor was a vestibular schwannoma and the smaller was a meningioma. Neurofibromatosis was not diagnosed in the patient. No recurrence was observed at the end of 9 years after the operation. The simultaneous occurrence of vestibular schwannoma and meningioma in the CPA appears coincidental. This association must be kept in mind if two different tumors are detected radiologically in the same CPA.     

Petrous bone osteoblastoma invading the cavernous sinus.

A 45-year old female was admitted complaining of double vision. A CT scan revealed a mass originating from the petrous part of the temporal bone with infiltration of the cavernous sinus. The patient was operated and a subtotal excision of the tumor was achieved. Pathological examination revealed benign osteoblastoma. During an 18 year follow up period, no progression of tumor has been detected.     

Medulloblastoma presenting as an extra-axial tumor in the cerebellopontine angle

Differences in the imaging characteristic of adult medulloblastomas have been reported, including involvement of lateral cerebellar hemispheres with an extra-axial appearance. We present a case report of this rare circumstance: a 40 year old man presented with a 3 weeks history of headache, morning vomiting and left hearing difficulties. Magnetic resonance imaging revealed a left cerebellopontine angle (CPA) tumor, like a well circumscribed homogeneously enhancing mass. Through a left suboccipital craniectomy the tumor was totally removed. It presented as a cerebellopontine angle tumor, like a meningioma, and not as an intra-axial tumor. Histological analysis revealed that the tumor was composed of densely packed with highly proliferative cells that produce a dense intercellular reticulin fiber network. Inmunohistochemical analysis showed positive expression to synaptophysin, specific neuronal enolase and cromogranin. Histological diagnosis was crucial to define it as a desmoplastic medulloblastoma the present case and to perform postoperative adjuvant therapy. Neurosurgeons should be aware of the possibility that a CPA tumor is of intraaxial origin, because this increase the variability on pathological diagnosis.     

VHL gene inactivation in an endolymphatic sac tumor associated with von Hippel-Lindau disease.

The authors present a case of endolymphatic sac tumor, a rare adenomatous tumor of the temporal bone, in a patient with von Hippel-Lindau (VHL) disease. Sequencing and microsatellite analysis of DNA samples from the tumor showed a 1-base pair deletion in exon 1 of the VHL gene and loss of heterozygosity at chromosome 3p25.5, the locus for the VHL gene. The results indicate that VHL gene inactivation contributed to the oncogenesis of endolymphatic sac tumor and provide molecular genetic proof that this tumor is associated with VHL disease.     

颞下经岩骨至岩斜区显微解剖学研究

目的 界定硬膜下磨除岩骨的安全范围,探索岩骨切除方法.方法 福尔马林固定成人头颅湿标本10例(20侧).模拟颞下经岩骨手术入路,观察岩骨磨除前后的显露范围及周围重要结构的解剖关系,观察结果测量拍照.结果 颞下经岩骨入路可先根据面听神经的位置结合内听道和岩骨嵴所成的角度判断出内听道在岩骨前表面的投影.以内听道为标志,可以将岩骨分为内听道周围部分和内侧岩尖部分共两部分来磨除岩骨.结论 采用颞下经岩骨入路可根据术中实际需要合理地磨除岩骨,进一步增加对岩斜区结构的显露,具有显露充分、操作简单、安全性高的特点.

Abstract：

Objective To explore the anatomical structure and identify the safe resecting region in the temporal base approach of transpetrosal subdura.To explore ways to grind petrous bone easily.Method The subtemporal approach was simulated in 10 ( 20 sides ) formalin - fixed cadaveric adult heads to observe the grinding of the bone.The results of observation were photographed and measured to provide the safe range of the grinding petrous bone.Results As a symbol of the auditory canal, bone was divided into the part of around the internal auditory canal and the petrous apex.The bone around the internal auditory canal was devided into the lateral internal auditory canal and upper part.Distance of about 5 mm to the internal auditory canal could be grinded.The yard of the inside petrous apex could be grinded safly.Grinding the subdural bone could increase the vertical angle up to 15°.Conclusions The subtemporal tentorial approach can increase the view on the structure of the posterior fossa.It gives the priority exposure for the base of posterior fossa tumors.     

乙状窦后入路桥小脑角区显微解剖研究

目的通过显微镜及神经内镜观察研究国人乙状窦后入路的桥小脑角区的结构，为临床应用提供解剖学依据。方法在5个新鲜国人头颅标本上模拟枕下乙状窦后手术入路．通过神经内镜和手术显微镜观察桥小脑角区的重要结构，测量内耳门后下缘到后半规管后缘中点的距离。结果颈静脉孔位于岩骨内侧面的下方，有岩下窦、乙状窦、颈静脉及第Ⅸ、Ⅹ、Ⅺ颅神经通过：内耳门位于岩骨内侧面中央，面神经多位于内耳门的前上，听神经位于内耳门后下，小脑前下动脉在内耳门处形成动脉袢，发出1～3支内听动脉。内耳门后下缘到后半规管后缘中点的距离左侧为（12．51±2．28）mm，右侧为（13．26±2．17）mm。结论结合显微镜和神经内镜有助于更全面的了解桥小脑角区解剖结构之间的关系，能最大程度减低损伤，更好的保护正常结构。     

Primary lumbar epidermoid tumor mimicking schwannoma.

A case of a primary lumbar epidermoid tumor is described. Intraspinal epidermoid tumors are rare. The differential diagnosis on this case was a nerve sheath tumor, such as aschwannoma, as the tumor entered the dural sac and caused dural ectasia. The diagnostic pitfalls of this feature of the tumor are discussed.