Manish Beniwal

Role of Dynamic Contrast-Enhanced Perfusion Magnetic Resonance Imaging in Grading of Pediatric Brain Tumors on 3T

Background/Aims: Perfusion magnetic resonance imaging (MRI) is useful for preoperative assessment of brain tumors. Dynamic susceptibility contrast perfusion MRI is commonly used for evaluation of brain tumors. Dynamic contrast-enhanced (DCE) MRI is an alternative method that has mainly been used in adult brain tumors. In this preliminary study, we report our initial experience with the DCE perfusion MRI in pediatric brain tumors. Methods: Sixty-four newly diagnosed pediatric brain tumor patients underwent DCE perfusion MRI on a 3-T scanner. Hemodynamic and kinetic parametric maps were generated and the regions with the highest values were measured on each map. Statistical differences were sought to differentiate between low-grade tumors, high-grade tumors, and medulloblastomas. The perfusion metrics of common posterior fossa tumors were also compared. Results: Relative corrected cerebral blood volume (rCBV) and fractional plasma volume measures differed significantly between high- and low-grade tumors (p < 0.05). High-grade tumors could be differentiated from low-grade tumors, with an rCBV cutoff value of 2.41 and 88.6% sensitivity and 65% specificity. There was no significant difference in Ktrans, Kep, Ve, or λtr between these 2 groups of tumors. rCBV, relative quantification of the cerebral blood flow, and permeability indices were found to be significantly different in various posterior fossa tumors, i.e., pilocytic astrocytoma, ependymoma, and medulloblastoma (p < 0.05). Conclusion: DCE-derived perfusion metrics are useful in differentiating high-grade tumors from low-grade ones and discriminating among various posterior fossa tumors in the pediatric age group.

Abscess within a Glioblastoma: Mimicking a Matryoshka Doll

BACKGROUND Abscess coexisting within a brain tumor is rare. Case reports in the literature primarily consist of sellar pathology and parenchymal lesions, including meningioma, glioma, and metastases. We report a case of glioblastoma with an intratumoral abscess in a middle-aged patient with no prior invasive procedure or systemic focus of infection. CASE DESCRIPTION A 45-year-old woman presented with new-onset generalized seizures and rapidly progressive left hemiparesis. Imaging showed a right frontal necrotic lesion with a peripherally enhancing wall and solid component posteriorly. There was no diffusion restriction within the lesion. She was afebrile, and there was no systemic focus of infection. With provisional diagnosis of malignant glioma, she underwent surgical resection of the lesion. A differential diagnosis of abscess was considered preoperatively because of the rapid increase in size of the lesion. At surgery, there was a pus-filled cavity with a few areas of grayish, soft, flimsy wall and thrombosed veins. This raised a strong suspicion of a coexisting abscess within a malignant glioma, which was confirmed by histopathologic and microbiologic examination. CONCLUSIONS It is important for neurosurgeons to be aware of this rare entity. The treatment protocol remains controversial and is primarily guided by expert opinion. It is important to aggressively treat the patient with antibiotics followed by adjuvant therapy for malignancy. The timing and administration of adjuvant therapy are unclear. We suggest a delay of chemotherapy until at least 4 weeks of therapy with sensitive antibiotics.

Wolf in Sheep's clothing: Intracranial actinomycosis masquerading as en-plaque meningioma

Background: Actinomycosis israeli is a gram-positive non-acid-fast bacterium and is the most common causative agent of actinomycosis. It usually presents as a brain abscess via a secondary spread from the cervicofacial region or lungs. However, presentation as an en-plaque lesion with bone involvement out of proportion to brain parenchyma is rare and needs to be acknowledged. Case Description: We report a case of intracranial en-plaque lesion in a 47-year-old female with restriction of mouth opening and right third nerve palsy for 1 year. Imaging showed hyperostosis of the maxilla, temporal base, sphenoid, and zygoma with dural thickening suggestive of a meningioma. Surgical decompression yielded a granulomatous lesion along with empirical antitubercular therapy. However, patient succumbed to the infection and final histopathology revealed actinomycosis infection. Conclusion: Adequate knowledge along with clinical suspicion are the pillars to treating this unfortunate disease. Cheek swelling with bone involvement should be actively sought as risk factors. This case presents a unique opportunity to identify the fox among the sheep by elucidating the characteristic imaging findings and intraoperative view of this rare entity.

Rare cranial nerve schwannomas: A retrospective review of nontrigeminal, nonvestibular cranial nerve schwannomas

Introduction: Intracranial schwannomas arising from non-trigeminal and non-vestibular sources are extremely rare constituting <0.8% of all schwannomas. In this article, we have analyzed our experience in the management of these rare tumors over a 10-year period. Material and Methods: There were a total of 16 cases, with 11 of them undergoing microsurgical resection and 5 undergoing stereotactic radiosurgery (SRS). Results: There were no fresh neurological deficit in any of these patients and two patients underwent postoperative SRS for residual tumor. One patient died due to postoperative septicemia. Conclusion: Knowledge of these lesions along with their clinicoradiological profile is essential to maintain a high index of suspicion and understand the nuances of treatment.

Supratentorial pure cortical ependymoma: An unusual lesion causing focal motor aware seizure

Ependymomas usually arise from the ependymal lining cells of the ventricular system and central canal of the spinal cord. Supratentorial ependymoma is a rare entity with the variable clinical course. In a small number of cases, ependymoma arises from supratentorial parenchyma. Only a few cases are reported in the literature. We report a case of 3-year-old girl with left frontal mass. Total removal of the mass lesion was performed without any neurological deficit. Pathological examination of the excised tumor was consistent with anaplastic ependymoma. We have discussed management strategy of this rare entity.

Occipital Intraosseous Hemangioma over Torcula: Unusual Presentation with Raised Intracranial Pressure

BACKGROUND Hemangiomas of the bone are benign, uncommon, slow-growing lesions accounting for <1.0% of all bony neoplasms. Intraosseous occipital hemangiomas are rare, and occipital hemangiomas presenting with features of raised intracranial tension are, with only 2 cases reported to date. CASE DESCRIPTION In this case report, we describe the unique case of a 30-year-old male patient presenting with raised intracranial pressure due to venous obstruction at the torcula. The patient underwent excision of the lesion and became symptom free. CONCLUSIONS Although these are benign lesions, they can have a varied clinical presentation. An understanding of the different clinical presentations and surgical nuances in excising such tumors can lead to early diagnosis and good patient outcome.

Management of Perforator Plunge in the Transverse Sinus

Plunging is rare with the use of automatic-release perforators. We describe the management of a case of plunging in the transverse sinus in a child who underwent suboccipital craniotomy. The perforator got stuck in the bone and transverse sinus. The perforator-bone complex was removed in one piece with suturing of the transverse sinus.

Azygous anterior cerebral artery with an anterior cranial fossa base meningioma.

Sir, A 42‑year‑old lady presented with headache and anosmia of nine months duration. She had progressive loss of vision, and generalized seizures. She was conscious, but had a reduced attention span. Her visual acuity was limited to perception of hand movements close to face. Her magnetic resonance imaging (MRI) of the brain revealed a large meningioma arising from the olfactory groove, and extending until the tuberculum sella [Figure 1]. The magnetic resonance angiography showed lifting of both anterior cerebral arteries (ACA) with a single distal ACA (azygous ACA) [Figure 2]. A bifrontal craniotomy and a subfrontal approach facilitated excision of the tumor. The tumor was intimately related to both the ACAs and the distal azygous ACA. It was excised and a very small portion of the tumor was left at the junction of both ACAs at the site of critical perforators [Figure 3]. The postoperative period was uneventful. An azygous distal ACA is seen in 0‑5% of humans. [1] However, an azygous ACA commonly occurs in lower primates; hence, this anomaly is referred as a “monkey’s type” of ACA. [2,3] The azygous ACA may be associated with malformations like holoprosencephaly, agenesis of corpus callosum, meningoceles, lipoma, arachnoid cyst, and porencephalic cyst. [4‑7] In the available literature, the association of an azygous ACA with a coexisting suprasellar tumor has not been described. The association of an azygous ACA with an anterior cranial fossa meningioma, as seen in our patient, may be coincidental. It can, however, pose a significant challenge during surgery. Large meningiomas of anterior cranial fossa base may be adherent to the ACAs and surgery may lead to injury of this vessels. When there is a single ACA, as in our case, the injury to this vessel can cause infarction of both medial frontal lobes leading to paraplegia. Presence of a vascular anomaly in a close vicinity to the tumor calls for more precision during surgery.

Surgical management of petroclival meningiomas: Factors affecting early post-operative outcome.

Abstract Introduction. Petroclival meningiomas pose a major challenge to the treating neurosurgeon. The philosophy of treatment has changed over the decades from a nihilistic attitude to that of aggressive total excision to now a more tempered, maximal safe excision preventing morbidity followed by adjuvant treatment. Despite the advances in neurosurgery, surgical management of these tumours is still associated with sizable morbidity and mortality. Material and methods. This is a retrospective study of surgically managed petroclival meningiomas at our institute. Clinical status, radiological features and surgical outcome were analysed. Results. Between January 2003 and August 2013, we have operated on 30 patients. The most common presenting complaints were varying degrees of cranial nerve involvement and cerebellar dysfunction. Surgery was done using one of the skull base approaches with the retrosigmoid approach being used maximally (22 cases). Total or near-total excision was possible in 11 cases. There was a post-operative deterioration in cranial nerve functions in all patients and deterioration in Karnofsky Performance Score in seven patients at discharge. Three improved to independent status on follow-up. There was mortality in two cases. Overall 23 of the 30 patients (76.6%) had favourable outcomes. Conclusions. These are challenging tumours to treat and are associated with sizable morbidity and mortality. On statistical analysis, we found that if the tumour has a size of 3–5 cm and petroclival in location with no sphenoid extension and the lesion is homogenous on T2-weighted images, then there was a trend towards gross total resection and favourable outcome.