Calcified vestibular schwannoma in the cerebellopontine angle

Fractionated Radiosurgical Treatment of Intracerebral Schwannoma: A Case Report and Literature Review

Intracranial schwannomas (ICS) unrelated to the cranial nerves are extremely rare; around 70 cases have been reported worldwide. The available literature consists of case reports and small series that present variable characteristics distinguishing these lesions. Brain parenchyma schwannomas are typically benign tumors with currently unknown origins. Diagnosis of intraparenchymal schwannoma is almost never made preoperatively. The management of these tumors usually consists of gross total resection, chemotherapy, and radiotherapy in cases of recurrence. The authors present a case of fractionated Gamma Knife radiosurgical treatment of intracerebral schwannoma following partial microsurgical resection.

Calcification and ossification in conventional schwannoma: A clinicopathologic study of 32 cases

Calcification and ossification are uncommon in schwannomas; however, when present these findings may cause diagnostic confusion with other mesenchymal tumors which more frequently harbor these features. We sought to better characterize the type and rate of calcification and ossification in schwannomas. Cases of schwannoma diagnosed at our institution from 2005 to 2019 were reviewed to determine the type and amount of calcification and ossification present. Of 2116 total cases of schwannoma reported during the study period, 38 cases harbored calcification or ossification per the pathology report. Thirty-two of the 38 cases had slides available for review, of which 27 (84.3%) showed calcification, nine showed ossification (28.1%), and four (12.5%) cases demonstrated both. Foci of ossification typically occurred adjacent to large vessels. Of the 27 cases showing calcification, coarse dystrophic calcification was seen in 22 cases, psammomatous calcification in nine cases, and combined dystrophic and psammomatous calcification was seen in four cases. Cases with psammomatous calcification predominantly occurred in spinal roots and cerebellopontine angle of a younger age group with almost equal gender distribution. All four cases tested for protein kinase cyclic adenosine monophosphate-dependent type I regulatory subunit alpha immunohistochemical stain demonstrated retained expression. We confirm that calcification and ossification are rare findings in schwannoma. Awareness that these features may be present in these tumors will prevent misdiagnosis and ensure appropriate clinical management.

Intraparenchymal schwannoma with calcification of the temporal lobe: Case report and literature review

RATIONALE

Intracranial schwannomas most frequently arise from the trigeminal nerve and the vestibular nerve. Schwannomas within the cerebral parenchyma are exceedingly rare. Additionally, calcification is an uncommon histopathological and radiological characteristic in schwannomas.

PATIENT CONCERNS

A 46-year-old man presented to us with sudden onset epileptic seizure and a 3-month history of intermittent headache. After admission, the physical and neurological examinations were all normal. Brain CT revealed an irregular, well-defined, hyperdense mass in the right temporal lobe. MRI showed a solid mass appearing iso- to hypointensity on T1-weighted imaging and heterogeneous intensity on T2-weighted imaging in the right temporal lobe; after Gd-DTPA administration, the lesion showed heterogeneous enhancement.

DIAGNOSIS

Histopathological examination revealed hyperchromatic nuclei and loose intercellular matrix with calcification. Immunohistochemical analysis demonstrated that the tumor was strongly positive for S100 protein but negative for GFAP and CK, which was consistent with a schwannoma.

INTERVENTIONS AND OUTCOMES

A surgical resection via the right temporal approach was performed. Intraoperatively, we noticed that the tumor was grayish yellow, capsuled, and located entirely within the temporal parenchyma. A gross total resection was achieved. The postoperative course was uneventful, and there was no epileptic seizure.

LESSONS

Intraparenchymal schwannoma with calcification is an uncommon histopathological and radiological characteristic in schwannomas. Intraparenchymal schwannoma with calcification is extremely rare. The early identification and appropriate surgical treatment should be highlighted.

Intramedullary schwannoma of the upper cervical spinal cord: a case study of identification in pathologic autopsy

Intramedullary schwannoma of the upper cervical spinal cord is rarely reported in forensic medicine. We herein report a case involving a patient who died of compression from an intramedullary schwannoma in the upper cervical spinal cord. A 30-year-old man initially presented with a five-day history of pain in the left chest that progressed to weakening in the left arm. Although the patient was treated with analgesic poultices, he developed inspiratory dyspnoea and died while working the next day without having undergone any medical imaging examination or surgical treatment. Anatomical and histopathological examinations revealed an intramedullary schwannoma in the left cervical spinal cord (C₃-C₅) underneath the spinal nerve root. The cause of death might have been asphyxia secondary to the tumour, which interfered with the nerve function in the respiratory muscles. This finding suggests that an autopsy is essential for pathologists and medicolegists to comprehensively undertake their due obligation to obtain "the first evidence", especially when there is a lack of directly related evidence. As part of the central nervous system, the spinal cord could be systematically included in a routine pathological autopsy in some cases.

Periventricular intraparenchymal schwannoma. Case report

A 60-year-old male presented with a rare case of periventricular schwannoma. Imaging studies revealed a partially calcified, well-enhanced tumor in the periventricular area of the left frontal horn. The preoperative diagnosis was low grade glioma, but postoperative pathological findings revealed that the tumor was schwannoma. Most intraparenchymal schwannomas are benign, so total extirpation is usually curative. However, this uncommon neoplasm is difficult to distinguish from mimics, especially low grade gliomas, with only preoperative radiological findings or intraoperative pathological findings. Based on our experience and analysis of the characteristic radiological and pathological features in previous cases, we suggest that an accurate intraoperative diagnosis is possible. The key element is the combination of correct interpretation of the intraoperative pathology analysis and careful evaluation of the preoperative radiological studies. An appropriate intraoperative judgment is important, because the treatment, including the surgical management, would be totally different for schwannoma and glioma.

Calcification of vestibular schwannoma: a case report and literature review

Calcification rarely occurs in vestibular schwannoma (VS), and only seven cases of calcified VS have been reported in the literature. Here, we report a 48-year-old man with VS, who had a history of progressive left-sided hearing loss for 3 years. Neurological examination revealed that he had left-sided hearing loss and left cerebellar ataxia. Magnetic resonance imaging and computerized tomography angiography showed a mass with calcification in the left cerebellopontine angle (CPA). The tumor was successfully removed via suboccipital craniotomy, and postoperative histopathology showed that the tumor was a schwannoma. We reviewed seven cases of calcified VS that were previously reported in the literature, and we analyzed and summarized the characteristics of these tumors, including the calcification, texture, and blood supply. We conclude that calcification in VS is associated with its texture and blood supply, and these characteristics affect the surgical removal of the tumor.

Schwannoma of the greater superficial petrosal nerve

The authors report the clinical features, imaging and surgical findings, and follow-up of 5 rare cases of schwannoma of the middle fossa with possible origin from the greater superficial petrosal nerve (GSPN). All patients presented to a single neurosurgical institution. The study design was a prospective follow-up of 5 cases of schwannomas of the middle fossa that most likely originated from the GSPN. The presenting features were burning pain in the eyes in 2 cases, epilepsy and behavioral changes in 2 cases, and headache in 1 case. Imaging studies showed a subtemporal mass on the anterosuperior aspect of the petrous bone in all cases. An enhancing tail on the MR images was highly suggestive of the origin of the tumor from the GSPN. All tumors were removed through a subtemporal extra- or intradural approach.

Partial to complete peripheral facial nerve palsy was encountered after surgery in 3 cases, which recovered completely. Dry eye was the long-term permanent deficit in all cases. Mid- to long-term follow-up of the cases has not revealed any tumor recurrence. The 5 cases of schwannoma of the middle fossa with possible origin from GSPN were managed successfully, and their clinical presentation, differential diagnosis, and management are discussed.

Undetermined fibrous tumor with calcification in the cerebellopontine angle

In this report, we introduce an undetermined fibrous tumor with calcification occurring in the cerebellopontine angle (CPA). A 51-year-old woman was admitted with a short history of dizziness. Computed tomography and magnetic resonance images revealed a 2×2×2 cm sized mass at the left CPA which was round and calcified. There was no dura or internal auditory canal involvement. At surgery, the tumor was located at the exit of 7th and 8th cranial nerve complex. It was very firm, bright yellow and well encapsulated. Histologic findings revealed that the tumor was predominantly composed of fibrous component, scant spindle cells and dystrophic calcification. Immunohistochemical staining demonstrated positive for vimentin and negative for epithelial membrane antigen (EMA), S-100 protein, CD34, factor XIIIa and smooth muscle actin. The diagnosis was not compatible with meningioma, schwannoma, metastatic brain tumors, and other fibrous tumors. Although the tumor was resected in total, long term follow-up monitoring is necessary due to the possibility of recurrence.