Dural-based Lesions Research Articles

Metastatic prostate adenocarcinoma to the brain – a clinicopathologic analysis of 21 cases

BackgroundBrain metastasis from prostate adenocarcinoma (PCa) is rare, often leading to death within a year. Its infrequent occurrence and atypical histopathologic features contribute to lower consideration in the differential diagnosis of tumor brain metastasis. This study aims to assess the clinical characteristics and distinctive histopathologic features of metastatic PCa in the brain for timely and enhanced diagnostic accuracy.DesignA retrospective search spanning 20 years (2003–2022) was conducted on our archives and identified 21 cases diagnosed as “metastatic prostate adenocarcinoma (mPCa)” in brain biopsies and resections. All existing slides were thoroughly reviewed to evaluate the histopathology of the mPCa.ResultThe mean age at presentation for brain metastasis was 70 years. Of 21 cases, 5 were dural-based lesions, 16 were true intraparenchymal metastases, including 2 sellar/suprasellar masses, 3 frontal, 3 temporal, 3 occipital, 1 cerebellum, and 4 involving multiple brain lobes. The average interval between initial diagnosis and brain metastasis was 90.75 months. Notably, brain metastasis was the initial presentation for one patient, while another patient, initially diagnosed with prognostic grade group (GG) 2 PCa in 1/12 cores, presented with isolated brain metastasis two years later. Architecturally, tumor cells were arranged in sheets or nests in most cases; however, four cases showed histologic cribriform patterns, and five displayed papillary architecture. Cytohistology varied from uniform monomorphic to highly pleomorphic cells with prominent nucleoli (8/19) and high mitotic activity. Interestingly, 1 case showed small round blue cell morphology, another had focal areas of rhabdoid and spindle cell differentiation, and 6 had cytoplasmic clearing. Almost half of the cases (47%) showed necrosis.ConclusionmPCa to the brain can present with variable histomorphology. Therefore, consideration of mPCa in the differential diagnosis of metastatic brain lesions, even with non-suggestive imaging, is imperative in male patients with or without a history of primary disease. Accurate and prompt diagnosis is crucial, given the recent advancements in treatment that have improved survival rates.

PSMA PET improves characterization of dural-based intracranial lesions in patients with metastatic prostate cancer

PurposeTheranostic approaches combining prostate-specific membrane antigen (PSMA)-PET/CT or PET/MRI with PSMA-targeted radionuclide therapy have improved clinical outcomes in patients with prostate cancer (PCa) especially metastatic castrate resistant prostate cancer. Dural metastases in PCa are rare but can pose a diagnostic challenge, as meningiomas, a more common dural based lesions have been shown to express PSMA. The aim of this study is to compare PSMA PET parameters between brain lesions classified as dural metastases and meningiomas in prostate cancer patients. MethodsA retrospective analysis of PSMA PET/CT scans in patients with PCa and intracranial lesions was conducted. Brain lesions were categorized as dural metastases or meningiomas based on MRI characteristics, longitudinal follow-up, and histopathological characteristics. Standardized uptake values (SUVmax) of each brain lesion were measured, along with SUV ratio referencing parotid gland (SUVR). SUVs between lesions classified as metastases and meningiomas, respectively, were compared using Mann-Whitney-test. Diagnostic accuracy was evaluated using ROC analysis. Results26 male patients (median age: 76.5 years, range: 59–96 years) met inclusion criteria. A total of 44 lesions (7 meningiomas and 37 metastases) were analyzed. Median SUVmax and SUVR were significantly lower in meningiomas compared to metastases (SUVmax: 2.7 vs. 11.5, p = 0.001; SUVR: 0.26 vs. 1.05, p < 0.001). ROC analysis demonstrated AUC 0.903; the optimal cut-off value for SUVR was 0.81 with 81.1 % sensitivity and 100 % specificity. ConclusionPSMA PET has the potential to differentiate meningiomas from dural-based metastases in patients with PCa, which can optimize clinical management and thus improve patient outcomes.

Intraventricular presentation of Rosai–Dorfman disease: a case report with review of literature

BackgroundRosai–Dorfman disease (RDD)/sinus lymphohistiocytosis is a rare benign lymphoproliferative disorder. Only 25% show extra-nodal manifestation, only 5% are seen involving the CNS, with intraventricular manifestation rarely reported. Our aim was to highlight important imaging features which would be useful in considering this entity as one of the differentials while encountering this rare entity.Case descriptionWe present a case of a 34-year-old female with complaints of headache, altered behavior and visual disturbances. MRI brain showed T2 hypointense lesion arising from the left choroid plexus with dense homogenous enhancement, with multiple additional extra-axial dural-based lesions and a small lesion involving right choroid plexus. Left parietal craniotomy was done, and the lesion was excised. Histopathology showed large foamy macrophages in eosinophilic background, with lymphophagocytosis (emperipolesis), confirming the diagnosis of Rosai–Dorfman disease.ConclusionsIntraventricular Rosai–Dorfman disease is a rare entity. Imaging features of T2 hypointense homogenously enhancing lesion with blooming on GRE, without features of calcification or hemorrhage, may be helpful in prompting adequate histopathologic evaluation.

Surgical resection of pediatric craniocervical junction Rosai-Dorfman histiocytosis-a case report and literature review.

Rosai-Dorfman disease (RDD) with craniocervical junction involvement is a rare clinical entity. We present herein a case of a pediatric patient with craniocervical junction RDD which was surgically treated. A 10-year-old female with a history of B-cell acute lymphoblastic leukemia (B-ALL) in remission and RDD presented with frontal migraine headaches. She previously had a right posterior chest wall lesion which was biopsy-proven RDD. She was found on imaging to have a dural-based right craniocervical junction lesion. Given her history of B-ALL, after a multidisciplinary discussion, the decision was made to proceed with resection with possible initiation of cobimetinib or clofarabine. The patient underwent a suboccipital craniotomy, C1 laminectomy, and resection of the dural-based lesion. Gross total resection was achieved, and histopathology confirmed the diagnosis of RDD. She was discharged home on postoperative day 4. No recurrence was seen on follow-up imaging at 3months. We conducted a systematic literature review examining all cases of pediatric intracranial RDD and all cases of craniocervical junction RDD. This represents, to the best of our knowledge, only the second case of pediatric craniocervical junction RDD. Although RDD is often self-limiting, medical treatment is often considered for intracranial disease, but tissue confirmation is necessary. Surgical resection provides histopathologic diagnosis and can sometimes serve as definitive treatment for a particular lesion.

IMMU-32. CAN PEMBROLIZUMAB TREAT RECURRENT GLIOBLASTOMA AND REVERSE HIV LATENCY?

Abstract Immunotherapy revolutionized treatment for many solid tumors. Early studies show that immunotherapy may be effective for recurrent glioblastoma. The ongoing Phase 2 LEEP-005 clinical trial (pembrolizumab+lenvima) is currently enrolling glioblastoma patients, but excludes patients with HIV. However, there is a strong need to treat this special patient population. One of the barriers to achieving cure in HIV patients is HIV latency within infect CD4+ T cells. Recently published data suggests that pembrolizumab can reverse HIV latency by forcing the HIV out of intracellular hiding into the plasma where anti-retroviral therapy can be effective. We present a case of a 39 year-old male with HIV and a Left Parietal Glioblastoma who had progressive disease following a subtotal resection and radiation alone due persistent neutropenia. Post-radiation MR brain wwo showed progressive disease in the left parietal lobe and new dural-based lesions in the left frontal and temporal lobes. HIV viral load was &amp;lt; 20 and CD4 count was 406 on HAART. The patient declined lenvima, but was amenable to bevacizumab. At 1 month follow-up, after 1 infusion of pembrolizumab 200mg and 2 infusions of bevacizumab, he achieved CR in the original site of disease and stable disease in the left frontal and temporal lobes. HIV viral load was 52. CD4 count was 660. Though it is too early to draw any firm conclusions, in our patient, pembrolizumab appears to induce HIV reversal, which is supported by an increase in the increase in his HIV viral load. The combination of pembrolizumab and bevacizumab appears to be effective at short-term follow-up. Our study is significant because there is limited evidence on the use of PD-L1 inhibitors in active HIV patients with cancer. To our knowledge, our case is the first reported case of the use of pembrolizumab in a patient with HIV and glioblastoma.

Nonmeningothelial Dural-Based Lesions: A Histopathological Analysis.

Introduction We report 30 cases of nonmeningothelial dural-based lesions encountered during a 3-year study period. Materials and Methods We retrospectively reviewed pathology records of patients operated for extra-axial, dural-based lesions during the years 2016 to 2018 and included nonmeningothelial lesions as a part of this study. Results Among the 3,243 neurosurgical specimens for histopathologic examination, only 30 (0.93%) were "nonmeningothelial dural-based lesions." Six (20%) patients were in the pediatric age group. Pathologic assessment identified 13 cases of solitary fibrous tumor/hemangiopericytoma (43.3%) and 7 cases of Ewing's sarcoma/primitive neuroectodermal tumor (23.3%). Two cases (6.7%) were of metastasis. Other lesions included a single case each of non-Hodgkin's lymphoma, undifferentiated sarcoma, solitary plasmacytoma, and granulocytic sarcoma. Nonneoplastic lesions included two cases each of Rosai-Dorfman disease and nonspecific inflammatory lesions. Conclusion Nonmeningothelial dural-based lesions being rare, thorough examination of morphological features is a must by the pathologist, to arrive at the accurate diagnosis. Ancillary tests, if required, should be employed in the context of the morphologic picture.

Vascular steal and associated intratumoral aneurysms in highly vascular brain tumors: illustrative case.

Intratumoral aneurysms in highly vascular brain tumors can complicate resection depending on their location and feasibility of proximal control. Seemingly unrelated neurological symptoms may be from vascular steal that can help alert the need for additional vascular imaging and augmenting surgical strategies. A 29-year-old female presented with headaches and unilateral blurred vision, secondary to a large right frontal dural-based lesion with hypointense signal thought to represent calcifications. Given these latter findings and clinical suspicion for a vascular steal phenomenon to explain the blurred vision, computed tomography angiography was obtained, revealing a 4 × 2-mm intratumoral aneurysm. Diagnostic cerebral angiography confirmed this along with vascular steal by the tumor from the right ophthalmic artery. The patient underwent endovascular embolization of the intratumoral aneurysm, followed by open tumor resection in the same setting without complication, minimal blood loss, and improvement in her vision. Understanding the blood supply of any tumor, but highly vascular ones in particular, and the relationship with normal vasculature is undeniably important in avoiding potentially dangerous situations and optimizing maximal safe resection. Recognition of highly vascular tumors should prompt thorough understanding of the vascular supply and relationship of intracranial vasculature with consideration of endovascular adjuncts when appropriate.

Staged Resection of Difficult-to-Treat Intracranial Meningiomas: A Systematic Review of the Indications, Surgical Approaches, and Postoperative Outcomes.

Introduction Meningiomas-the most common extra-axial tumors-are benign, slow-growing dural-based lesions that can involve multiple cranial fossae and can progress insidiously for years until coming to clinical attention secondary to compression of adjacent neurovascular structures. For complex, multicompartmental lesions, multistaged surgeries have been increasingly shown to enhance maximal safe resection while minimizing adverse sequela. Here, we systematically review the extant literature to highlight the merits of staged resection. Methods PubMed, Scopus, and Web of Science databases were queried to identify articles reporting resections of intracranial meningiomas using a multistaged approach, and articles were screened for possible inclusion in a systematic process performed by two authors. Results Of 118 identified studies, 36 describing 169 patients (mean age 42.6 ± 21.3 years) met inclusion/exclusion criteria. Petroclival lesions comprised 57% of cases, with the most common indications for a multistaged approach being large size, close approximation of critical neurovascular structures, minimization of brain retraction, identification and ligation of deep vessels feeding the tumor, and resection of residual tumor found on postoperative imaging. Most second-stage surgeries occurred within 3 months of the index surgery. Few complications were reported and multistaged resections appeared to be well tolerated overall. Conclusions Current literature suggests multistaged approaches for meningioma resection are well-tolerated. However, there is insufficient comparative evidence to draw definitive conclusions about its advantages over an unstaged approach. There are similarly insufficient data to generate an evidence-based decision-making framework for when a staged approach should be employed. This highlights the need for collaborative efforts among skull base surgeons to establish an evidentiary to support the use of staged approaches and to outline those indications that merit such an approach.

Giant convexity enchondroma mimicking a meningioma: A case report and literature review

Abstract Most intracranial enchondromas are located in the skull base. Intracranial enchondromas over convexity are very rare benign extra-axial tumors that tend to present with protracted symptomatology and as large dural-based space-occupying lesions. We report a large convexity enchondroma in a 23-year-old male who presented with 3 years of recurrent seizures. Surgical gross total removal resulted in a good outcome. This case report emphasizes the unusual location of enchondroma in the form of an extra-axial space-occupying lesion in the parietooccipital lobe and further adds to the literature on this pathological entity. Our objective is to report this rare case and review the pertinent literature, especially concerning presentation, pathology, and management.

Meningioma Presenting with Spontaneous Venous Intraparenchymal Hemorrhage

A 65-year-old woman with a known right-sided, dural-based lesion and metastatic pancreatic neuroendocrine tumor presented with multiple days of progressive lethargy and left-sided weakness culminating with obtundation and dilated pupils. Computed tomography demonstrated an acute right convexity subdural hematoma and a frontotemporal intraparenchymal hemorrhage with 1.3 cm of midline shift, uncal herniation, and an increase in size of now a hemorrhagic dural-based lesion. She underwent emergency hemicraniectomy for evacuation of subdural hematoma and resection of hemorrhagic meningioma with excellent postoperative result including improvement in midline shift and gross total resection of lesion. Pathology was consistent with a World Health Organization grade II meningioma with a chordoid component. She underwent adjuvant stereotactic radiosurgery and cranioplasty and made a full neurologic recovery. Identification of hemorrhagic meningioma as the underlying pathology causing multicompartmental hemorrhage is crucial. We recommend single-stage decompression with extraaxial clot evacuation and resection of the meningioma when feasible.

QLTI-15. VENOUS SINUS THROMBOSIS AFTER BRAIN TUMOR RESECTION

Abstract Post-operative venous sinus thrombosis (POVST) is an uncommon complication from a craniotomy for brain tumor resection. There are few data in how to treat POVST, including the use of anticoagulation and follow-up. It has been found that POVST is more common in dural-based lesions especially located on or near a sinus, however treatment has not been standardized. We retrospectively reviewed our POVST cases between January 2018 to December 2020 for brain tumor resection, whether we chose to start anticoagulation or not, and the eventual outcome. We also performed a literature review on the topic to compare findings and management. We identified 14 cases of POVST; 8 of the cases were for extra-axial masses. Of the 14, 6 POVST had clot involving the superior sagittal sinus (SSS), with 3 being discharged with a direct oral anticoagulant (DOAC) and one being discharged on warfarin. With transverse sinus involvement, 6 cases were noted (with no SSS clot), with 2 started on a DOAC and 2 being started on ASA 81mg. In the sigmoid sinus there were 2 cases and did not receive anticoagulation. Of the 14 total cases, 1 was symptomatic (new-onset seizures) necessitating surgical recanalization and no other cases had symptoms attributed to the POVST. Two patients died from unrelated reasons prior to receiving any outpatient imaging, and all other patients had recanalization of their involved sinuses within 2-5 months. There were no complications in patients receiving anticoagulation. Our literature review didn't show a standardized method in POVST treatment. There is also disagreement in what anticoagulation should be used, and if it is necessary. Based on our retrospective analysis and literature review, if the clot is symptomatic, involves the SSS, or propagates, we recommend anticoagulation. Outside the SSS, it should be determined on a case-by-case basis, but anticoagulation may not be necessary.

ODP593 Thyroid sarcoidosis: case study and literature review

Abstract Introduction Sarcoidosis is a disorder characterized by noncaseating granulomas, most commonly in the lungs, lymph nodes, and skin. Patients often present with cough, skin or eye changes, enlarged lymph nodes, fatigue, or are found to have incidental findings on chest imaging. While any organ can be involved, thyroid involvement is rare, reportedly seen postmortem in 4.2 to 4.6% of sarcoidosis cases. We describe the case of a young adult male with thyroid sarcoidosis in addition to neurosarcoidosis. Case Presentation A 37-year old African American male was found to have a goiter on routine examination. Work up revealed an elevated TSH level of 11.1 uIU/mL (0.4-4. 0) with a free T4 of 0.91 ng/dL (0.7-1.9). Thyroid ultrasound demonstrated a dominant right-sided thyroid mass measuring 5.5×3.1×4.1 cm. Fine needle aspiration cytology reported polymorphic lymphocytes, few lymphohistiocytic aggregates, scant hurthle cells, and multinucleated giant cells. Thyroidectomy was recommended; intra-operatively the right thyroid lobe contained a 5-cm firm, hard, whitish mass in the mid inferior portion which could not be excised due to extensive fibrosis. Incisional biopsy was performed demonstrating fibrotic lymphocytic thyroiditis and non-caseating granulomas with no evidence of malignancy. He presented to the ER six weeks later with confusion, headaches, retro-orbital pain, and periodic involuntary movements in all extremities. MRI of the brain showed dural-based lesion in the right lateral and inferior temporal fossa. He underwent craniotomy and excisional biopsy of the lesion, which showed granulomatous inflammation, favoring a diagnosis of neurosarcoidosis. In a future admission, he was found to have dural venous sinus occlusion and new granulomas on brain MRI. It was then noted that previous thyroid biopsy revealed granulomatous disease, which was then linked to his sarcoidosis. He was discharged on prednisone and methotrexate with eventual further neurological complications. Discussion Thyroid sarcoidosis is very rare and because of this, it is frequently misdiagnosed initially and fine needle aspiration of the thyroid is frequently nondiagnostic. Histopathology is usually necessary to rule out malignancy and identify non-caseating granulomas. In some reported cases, thyroid sarcoidosis shared clinical, ultrasonographic, and even cytologic features with papillary thyroid cancer. Our case was unique for several reasons. Firstly, although not immediately noted, incisional thyroid biopsy was the first diagnostic clue of sarcoidosis. More commonly, patients are already diagnosed with systemic sarcoidosis. Additionally, typical findings such as mediastinal hilar adenopathy, hypercalcemia, and elevated angiotensin converting enzyme levels were absent. Although sarcoidosis of the thyroid is rare and often benign, it is important to consider this differential diagnosis while ruling out more likely causes as early detection can lead to early treatment and prevent adverse outcomes. The ideal treatment remains unclear, regarding whether to treat pharmacologically or concurrently with surgical intervention. Presentation: No date and time listed

Ventral Intrameningeal Cyst Treatment and Management: Technical Note

Intrameningeal cysts are rare lesions without definitive etiologies that can involve the dura or arachnoid mater. Spinal arachnoid cysts have been described, and several different etiologies have been hypothesized. This includes one-way valve mechanisms, traumatic herniation of arachnoid through the dura, and abnormal arachnoid membrane proliferation. To the authors' knowledge, no such descriptions exist regarding purely dural-based cystic lesions; however, the authors hypothesize similar mechanisms may be involved. Most notably, a traumatic injury to the dura leading to a one-way valve mechanism may allow for egress of cerebrospinal fluid between the dural layers, splitting them open. This progressive enlargement can lead to displacement of neural elements and subsequent neurological compromise. We describe a 17-year-old girl who presented with progressive neck and back pain, left upper-extremity numbness, bilateral lower-extremity weakness, paresthesias, and numbness without obvious etiology despite an extensive neurologic investigation. She had undergone conservative management options including multiple medications, physical and chiropractic therapy, and epidural steroid injections. Computed tomography myelography revealed a cerebrospinal fluid leak into the lumbar epidural space for which surgical exploration was performed. Despite utilizing fluoroscopy and intrathecal fluorescein, no leak source was identified. Fluid collection was found contained within the dural layers rather than the epidural space. An intracystic blood patch was performed with near-complete resolution of the lesion by 6-week follow-up and near-complete return of neurologic function. Ventral panspinal cysts are an exceedingly rare cause of radiculopathy and myelopathy that can be resolved by an intracystic blood patch.

De Novo Glioblastoma Masqueraded within a Hemispheric Dural Meningiomatosis: Rare Imaging Findings and Rationale for Two-Staged Resection

Introduction Collision tumors present as histologically different juxtaposed neoplasms within the same anatomical region, independent of the adjacent cell population. De novo intracranial collision tumors involving metachronous primary brain neoplasms alongside dural meningiomatosis are not well documented in the literature. Clinical Presentation We present staged surgical management of a 72-year-old female with known left hemispheric stable dural-based convexity mass lesions over 10 years and new-onset expressive aphasia and headaches. MRI had revealed left supratentorial dural-based enhanced masses consistent with en plaque meningiomatosis. Embolization angiography showed an unusual tumor blush from an aberrant branch of anterior cerebral artery suggesting a deeper focal intra-axial nature; a stage 1 craniotomy for dural-based tumor resection was completed with diagnosis of a meningioma (WHO grade 1). Intraoperatively, a distinct intra-axial deep discrete lesion was verified stereotactically, concordant with the location of tumor blush. The patient made a complete neurological recovery from a transient postoperative supplemental motor area syndrome in a week. Subsequent postoperative follow-up showed worsening of right hemiparesis and MRI showed an increase in residual lesion size and perilesional edema, which prompted a stage 2 radical resection of a glioblastoma, WHO grade 4. She improved neurologically after surgery with steroids and physical therapy. At 15 months following adjuvant therapy, she remains neurologically intact throughout the postoperative course, with no recurrent tumor on MRI. Conclusion A de novo glioblastoma presented as a masquerading lesion within hemispheric convexity meningiomatosis in an elderly patient with no prior radiation/phakomatosis, inciting a non-causal juxtapositional coexistence. The authors highlight rare pathognomonic angiographic findings and the rationale for two-staged resections of these collision lesions that led to excellent clinicoradiological outcome.

The Middle Meningeal Artery: Branches, Dangerous Anastomoses, and Implications in Neurosurgery and Neuroendovascular Surgery

The middle meningeal artery (MMA) has always been the workhorse corridor for devascularization of dural-based intracranial lesions and, more recently, has been established as a target for the endovascular management of chronic subdural hematomas. The MMA anatomy is complex and deceitful, and its territory of irrigation (including cranial nerves) is poorly understood. Furthermore, MMA variations and anastomoses are more frequent than expected, which may predispose to procedure-related morbidity. A literature search was conducted in electronic databases per PRISMA guidelines for studies describing normal and abnormal MMA anatomy including variations in MMA origin and dangerous anastomoses. Our institutional case series of greater than 100 MMA embolizations for management of chronic subdural hematomas were reviewed for abnormal MMA anatomy, and clinically relevant case examples are presented. In this article, we provide a comprehensive review of the MMA to provide a better understanding and appreciation of this artery, including pearls and pitfalls, that we hope will aid the neurosurgeon and neurointerventionalist in safely tackling these lesions.

Pitfall of gamma knife radiosurgery as primary treatment of Dural-based lesion: a case report and review of the literature.

Pitfall of gamma knife radiosurgery as primary treatment of Dural-based lesion: a case report and review of the literature.

A Giant Nondural-Based Lumbosacral Clear Cell Meningioma Mimicking Schwannoma: A Case Report and Review of the Literature.

Spinal clear cell meningiomas (CCMs) are rare and dural-based lesion usually affecting the younger population. We report the rare case of giant nondural-based spinal CCM mimicking schwannoma and review the literature. A literature search was performed at PubMed and Embase until January 1, 2020. A total of 19 cases of nondural-based spinal CCM was reported. The following relevant data were extracted: authors, publication year, patient and tumor characteristics, treatment, and outcome. The mean age of the presentation was 20.58 years. Twelve (63.16%) were female and seven patients (36.84%) were male. The most common location was lumbosacral region 15 (79%). Fifteen (79%) tumors had cranio-caudal dimension ≤2 vertebral level, and only four (21%) tumors had dimension ≥2 vertebral level. Gross total resection (GTR) was performed in 18 (95%) patients and subtotal resection (STR) in 1 patient. Recurrences were reported in five (26.14%) patients. Four of them showed recurrences within 6 months; earliest at 2.3 months in the patient had undergone STR. Our patient is 19-year-old male diagnosed with a lumbosacral intradural lesion. Craniocaudal dimension is ≥2 vertebral level shows the foraminal extension and vertebral scalloping. GTR is performed. Intraoperatively, the tumor has foraminal extension and shows attachment with right S1S2 nerve root. No dural attachment is found. Six-month follow-up magnetic resonance image shows no evidence of disease. Nondural-based spinal CCMs are extremely rare and should be kept as a differential diagnosis in young patients with giant intradural tumor, and whose radiological features suggesting of schwannoma. It affects young patients and usually involves more than one vertebral level. The chances of recurrences and metastasis are always high even after GTR; hence, close follow-up of the entire neuraxis is warranted.

Anaplastic Lymphoma Kinase‐Positive Inflammatory Myofibroblastic Tumor Mimicking Meningioma: A Case Report

A 15-year-old girl presented with intermittent nausea and vomiting, headache, and vision changes. MR imaging of the brain revealed an avidly enhancing infratemporal dural-based mass arising from the tentorium, with hyperintensity on T2WI and transdural extension into the posterior cranial fossa. The well-encapsulated fibrous tumor was resected en bloc after cauterization of its rich tentorial arterial supply. Histologic examination demonstrated pleomorphic myofibroblastic cells admixed with an inflammatory infiltrate. Spindle cells showed strong, diffusely positive immunostaining for anaplastic lymphoma kinase, and genomic sequencing uncovered a tropomyosin 3 gene and anaplastic lymphoma kinase fusion and an activating mutation in the Kirsten rat sarcoma oncogene. A diagnosis of inflammatory myofibroblastic tumor was made. Primary intracranial involvement of inflammatory myofibroblastic tumor is exceptionally rare, and few cases that feature an anaplastic lymphoma kinase translocation have been described. Inflammatory myofibroblastic tumor‐CNS is an important differential diagnosis for dural-based lesions in children and young adults due to its propensity for recurrence and malignant degeneration.

Dural-based lesions: is it a meningioma?

Meningiomas are the most common extra-axial intracranial neoplasms with typical radiological findings. In approximately 2% of cases, histopathological reports reveal different neoplasms or non-neoplastic lesions that can closely mimic meningiomas. We describe radiological features of meningioma mimics highlighting imaging red flags to consider a differential diagnosis. A total of 348 lesions with radiological diagnosis of meningiomas which underwent to surgical treatment or biopsy between December of 2000 and September of 2014 were analyzed. We determined imaging features that are not a typical finding of meningiomas, suggesting other lesions. The following imaging characteristics were evaluated on CT and MRI: (a) bone erosion; (b) hyperintensity on T2WI; (c) hypointensity on T2WI; (d) bone destruction; (e) dural tail; (f) leptomeningeal involvement; (g) pattern of contrast enhancement; (h) dural displacement sign. We have a relatively high prevalence of meningioma mimics (7.2%). Dural-based lesions with homogeneous contrast enhancement (52%) are easily misdiagnosed as meningiomas. Most lesions mimic convexity (37.5%) or parafalcine (21.9%) meningiomas. We have determined five imaging red flags that can alert radiologists to consider meningioma mimics: (1) bone erosion (22.2%); (2) dural displacement sign (36%); (3) marked T2 hypointensity (32%); (4) marked T2 hyperintensity (12%); (5) absence of dural tail (48%). The most common mimic lesion in our series was hemangiopericytomas, followed by lymphomas and schwannomas. The prevalence of meningioma mimics is not negligible. It is important to have awareness on main radiological findings suggestive of differential diagnosis due to a wide range of differentials which lead to different prognosis and treatment strategies.

Thalidomide Use for Complicated Central Nervous System Tuberculosis in Children: Insights From an Observational Cohort.

Much of the neurological sequelae of central nervous system (CNS) tuberculosis (TB) is due to an excessive cytokine-driven host-inflammatory response. Adjunctive corticosteroids, which reduce cytokine production and thus dampen the inflammation, improve overall survival but do not prevent morbidity. This has prompted investigation of more targeted immunomodulatory agents, including thalidomide. We describe a retrospective cohort of 38 children consecutively treated with adjunctive thalidomide for CNS TB-related complications over a 10-year period. The most common presenting symptom was focal motor deficit (n = 16), followed by cranial nerve palsies and cerebellar dysfunction. Three of the 38 children presented with large dural-based lesions, manifesting as epilepsia partialis continua (EPC), 4 presented with blindness secondary to optochiasmatic arachnoiditis, and 2 children developed paraplegia due to spinal cord TB mass lesions. Duration of adjunctive thalidomide therapy (3-5 mg/kg/day) varied according to complication type. In children compromised by TB mass lesions, the median treatment duration was 3.9 months (interquartile range [IQR], 2.0-5.0 months), whereas in children with optic neuritis it was 2.0 months (IQR, 1.3-7.3 months) and in EPC it was 1.0 months (IQR, 1-2.5 months). Satisfactory clinical and radiological response was observed in 37 of the children. None of the children experienced rashes, hepatitis, or hematologic derangements or complained of leg cramps. This study is the largest cohort of adult or pediatric patients treated with adjunctive thalidomide for CNS TB-related complications. The drug has proved to be safe and well tolerated and appears to be clinically efficacious. The potential role of thalidomide or analogues in the treatment of other tuberculous meningitis-related complications requires further exploration.