Calcifying pseudoneoplasm of the neuraxis in direct continuity with a low‐grade glioma: A case report and review of the literature

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are presumed to be a non‐neoplastic reactive pathology, based on the frequent finding of granulomatous inflammation. To our knowledge, there are few reports of CAPNON in association with a neoplasm. Here, we report the case of a 62‐year‐old man presenting with headache, which was caused by CAPNON in the left cingulate gyrus. CT scan revealed a calcified mass exhibiting gradual growth and increasing peritumoral edema. MRI showed an intra‐axial hypointense mass on T1‐ and T2‐weighted images. Development of a peri‐lesional hyperintense lesion on T2‐weighted images suggested local edema or tumoral invasion. Gadolinium‐enhanced T1‐weighted images revealed mild peripheral enhancement of the calcified nodule. L‐methyl‐¹¹C methionine‐positron emission tomography revealed the uptake of tracer in the calcified nodule. The calcified mass and its enveloping brain tissue were removed using a parietal craniotomy. The calcified tissue was surrounded by spindle‐shaped cells positive for GFAP and nestin. The MIB‐1 labeling index of spindle cells was around 10% (i.e. a hot spot). Fourteen months after surgery, gadolinium‐enhanced MRI evidenced growth of a tiny residual lesion. Therefore, this report illustrates a potential case of CAPNON arising from low‐grade glial neoplasm.     

Multiple calcifying pseudoneoplasms of the neuraxis (MCAPNON): Distinct entity,CAPNON variant,or old neurocysticercosis?

We report a case of multiple calcifying pseudoneoplasms of the neuraxis (MCAPNON) with associated multifocal perivascular microcalcifications and vascular calcinosis. Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a very rare condition that may arise in extra‐axial and occasionally, in intra‐axial locations. Moreover, it is nearly always a solitary mass with only one case with two lesions reported. While the etiology and pathogenesis of CAPNON remains unclear, the histopathology findings of this entity have been well described. We report a case of a 62‐year‐old woman with 18 calcifying radiologic lesions involving bilateral cerebral hemispheres. Histologically, these lesions have features similar to that reported for CAPNON, including nodular calcification with fibro‐osseous components and peripheral histiocytic reaction. The patient had a poorly documented diagnosis of neurocyticercosis 32 years prior, although without tissue confirmation. The lack of detectable cysticercus serum antibody titers, and absence of residual larval or cyst wall tissue render multifocal calcific involution of that parasite unprovable although still plausible. We also raise the possibility of a blood–brain barrier derangement and/or a metabolic disorder as an alternative etiology. Whether this case of MCAPNON shares the same pathogenesis as the usual solitary CAPNON is unclear.     

Tumor‐to‐tumor metastasis to the central nervous system

Tumor‐to‐tumor metastasis is a well‐recognized phenomenon. Meningioma is the most common intracranial host tumor, with the breast and lung being the most common primary sites. We report herein two such cases of metastasis from pulmonary adenocarcinoma and malignant melanoma (MM) of vulva, respectively. Case 1: a 69‐year‐old female smoker who had a history of right upper lobectomy of lung for adenocarcinoma presented with a headache and altered mental status, and was found to have a left temporal contrast‐enhancing mass with massive surrounding edema on MRI. The resection specimen revealed foci of metastatic adenocarcinoma within a microcystic meningioma. Case 2: a 75‐year‐old woman with a history of radical vulvectomy for MM died of widespread systemic metastasis of MM. At autopsy, a 2.5 × 2 × 2 cm firm nodule attached to the falx was incidentally found, with focal black discoloration at the periphery of the mass. Histologic examination showed a fibroblastic meningioma with a focus of metastatic MM. Case 1 is the first case report describing a microcystic variant of meningioma harboring metastatic carcinoma. Although MM is one of the most common metastatic brain tumors, MM‐to‐meningioma metastasis is reportedly extremely rare, but can occur.     

Parasellar Solitary Fibrous Tumor of Meninges: Magnetic Resonance Imaging Features With Pathologic Correlation

Solitary fibrous tumor (SFT) is a benign mensenchymal neoplasm of spindle-cell origin. The authors report the case of a 50-year-old man with SFT arising from the meninges of the left parasellar region with cavernous sinus involvement. The tumor was demonstrated isointense on T1-weighted and heterogeneously hypointense on T2-weighted magnetic resonance imaging (MRI) with strong contrast enhancement. The preoperative MRI diagnosis was meningioma or hemangiopericytoma. Pathological study revealed an SFT that stained positive immunohistochemically for CD34 and vimentin.     

Calcifying pseudoneoplasm of the neuroaxis presenting with refractory seizures: Case report and literature review

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare benign lesions that can arise anywhere within the central nervous system. The etiology of these lesions remains unknown and diagnosis is made on pathohistological analysis. We present the case of a 35-year-old male patient with a history of epilepsy since childhood who was evaluated for refractory seizures. MRI revealed a small lesion in the left-posterior temporal lobe suspected to be a cavernoma. A gross total resection of the lesion was achieved via a left temporal craniotomy and pathological analysis revealed CAPNON. At 6 months follow-up, the patient remained neurologically intact and his seizures had ceased.     

Concurrent spinal nerve root schwannoma and meningioma mimicking single‐component schwannoma

We present a first case of concurrent tumors consisting of schwannoma and meningioma arising at the same spinal level in a patient without neurofibromatosis. A 49‐year‐old man without clinical evidence of neurofibromatosis presented with a 5‐month history of right neck pain. MRI demonstrated an extradural tumor involving the right‐sided C2 nerve root with a small intradural component. T1‐ and T2‐weighted and contrast‐enhanced MRI could not differentiate the intradural tumor as different from the extradural tumor. Total removal of the tumors was performed. No contiguity of the extradural tumor with the intradural tumor was seen. The intradural tumor attached strongly to the dura mater around the C2 nerve root exits. Intraoperative pathological diagnosis confirmed the extradural tumor as schwannoma and the intradural tumor as meningioma. We therefore thoroughly coagulated the dura mater adjacent to the intradural tumor and resected the dura mater around the nerve root exits together with the tumor. Pathological examination revealed that the resection edge of the extradural component consisted of a spinal nerve with thickened epineurium and was free of neoplastic cells. No schwannoma component was evident in the intradural tumor. No obvious transition thus existed between the extra‐ and intradural tumors. Distinguishing these tumors prior to surgery is critical for determining an optimal surgical plan, as schwannoma and meningioma require different surgical procedures. We therefore recommend a careful review of preoperative imaging with the possibility of concurrent tumors in mind.     

Multiple calcifying pseudoneoplasms of the neuraxis

Calcified pseudoneoplasms of the neuraxis (CAPNON) are a rare diagnostic entity. They have been reported intra‐cranially as well as in the spine, and are most commonly found at the skull base. This is a case report of a 38‐year‐old woman who presented with bilateral CAPNON, diagnosed 8 years apart. While there are approximately 46 reported in the current literature of cerebral and spinal fibro‐osseous lesions, this is the first report of separate lesions.     

Meningioma–primary brain lymphoma association

The authors report a rare meningioma–primary cerebral B cell lymphoma association that occurred in an insulin‐dependent type‐I diabetic woman. The woman was initially operated on because of meningothelial meningioma of the fronto‐basal region, and 2 months later showed a primitive‐non‐Hodgkin B cell lymphoma, localized in the same area as the meningioma. The published literature on the meningioma–primary cerebral lymphoma association is revised.     

An unusual case of cervical clear-cell meningioma in pediatric age

Introduction and background A 4-year-old girl was admitted with complaints of diplegia, right lower limb monoplegia, and left lower limb monoparesia. Cervical magnetic resonance imaging revealed an intradural-extramedullary tumor at the level of C1–C2. The tumor was resected totally. Histopathologic diagnosis revealed clear-cell meningioma. Discussion Intraspinal clear-cell meningioma (ICCM) is a rare aggressive variant of meningioma. There are only 25 cases reported to date, and only 13 of them are in pediatric age group. Of these 25 ICCM cases, only two are at cervical region. This report is the first ICCM case at upper cervical region (C1–C2) in both adult and pediatric age populations.     

Intraventricular metaplastic meningioma in a child: case report and review of the literature

Childhood meningiomas are rare and display important differences from adult forms. We report the first case of an intraventricular metaplastic meningioma arising in a child. A 7‐year‐old female underwent resection of an enhancing tumor arising within the left lateral ventricle. It was composed of monomorphic cells embedded within an abundant myxoid stroma. The cells demonstrated epithelial membrane antigen and vimentin immunoreactivity. Ultrastructural analysis demonstrated intermediate filaments, complex intercellular interdigitations and desmosomes, and a diagnosis of myxoid (metaplastic) meningioma was rendered. This case reflects the higher incidence of intraventricular meningiomas in childhood and greater incidence of intraventricular meningiomas in the left lateral ventricle. Recognition of the grade I myxoid meningioma in this case is paramount since chordoid meningiomas, which share similar histologic features, are of a higher grade and worse prognosis.     

Tumor‐to‐tumor metastasis from pituitary carcinoma to radiation‐induced meningioma

Radiation‐induced meningioma and pituitary carcinoma are both uncommon. Tumor‐to‐tumor metastasis (TTM) from pituitary carcinoma to meningioma, to our knowledge, has not been previously reported. A 67‐year old man presented with a previous history of transcranial subtotal resection of pituitary adenoma, at the age of 36, followed by radiotherapy. The follow‐up was uneventful for the following 31 years. The patient presented with worsening sight and numbness of the right arm. Three separate lesions were found on MRI. Histological examinations revealed pituitary carcinomas and TTM from pituitary carcinoma to meningioma. A constant surveillance is necessary for patients with pituitary tumor, especially those followed by radiotherapy.     

Lateral ventricular meningioma encapsulated by the dura‐like membrane

The first case of a ventricular meningioma that was encapsulated by the dura‐like membrane is reported. Magnetic resonance imaging (MRI) showed a heterogeneous mass with a low intensity rim in the trigone of the right lateral ventricle of a 63‐year‐old male. Histological examination revealed that the tumor was a transitional meningioma encapsulated by a thick dura‐like membrane. Moreover, abundant clusters of the dura‐like connective tissue existed in the tumor, indicating that both the dura‐like capsule and the dura‐like clusters in the tumor were created by the tumor cells.     

Synchronous intravascular large B‐cell lymphoma within meningioma

Intravascular large B‐cell lymphoma is a rare and aggressive lymphoma with a dismal prognosis. Synchronous intravascular large B‐cell lymphoma within meningioma has not previously been documented. We report a case of a 73‐year‐old woman of Asian descent who presented with fever of unknown origin with generalized weakness. CT scan and MRI of the head revealed a dural‐based mass lesion consistent with meningioma in the left frontal cerebral convexity. Surgery was performed to remove the tumor and histopathology showed a meningioma within which was a synchronous intravascular large B‐cell lymphoma. The hematology and oncology services were consulted and palliative treatment was initiated due to the patient's poor Eastern Cooperative Oncology Group performance status. The patient died within 30 days post‐surgery. To the best of our knowledge, this case represents the first report of synchronous intravascular large B‐cell lymphoma within a meningioma.     

Synchronous meningioma and anaplastic large cell lymphoma

Synchronous primary brain tumors are exceedingly rare. When they occur, most cases are associated with metastatic disease. To the best of our knowledge, we report the first case of an atypical meningioma infiltrated by a T‐cell‐primary central nervous system lymphoma (PCNSL), specifically anaplastic large cell lymphoma (ALCL). We present a novel, unifying, plausible mechanism for its origin based on theories in the current literature. A 65‐year‐old man with a history of near‐total resection of atypical meningioma presented with a complaint of progressive headaches. Imaging revealed recurrent tumor. Left frontal‐temporal craniotomy with near‐total tumor resection followed by radiation was performed. Recurrent symptomatic tumor led to repeat left frontotemporal craniotomy with tumor resection and partial anterior temporal lobectomy. Part of the specimen showed predominantly fibrotic neoplasm composed of nests and whorls of meningothelial cells, highlighted by epithelial membrane antigen (EMA) staining. The remainder of the specimen consisted of densely cellular neoplasm centered in connective tissue, including areas involved by meningioma. This tumor was composed of moderately large lymphoid cells with large nuclei, prominent nucleoli, and amphophilic cytoplasm. These cells were strongly immunoreactive for CD3 and CD30 but remained unstained with EMA, anaplastic lymphoma kinase‐1 (ALK‐1), CD15 or cytotoxic associated antigen TIA‐1. Smaller mature lymphocytes, chiefly T‐cells, were intermixed. The morphologic and immunohistochemical features were considered typical of anaplastic large T‐cell lymphoma. The pathogenesis of this association may have been due to radiation‐mediated breakdown of the blood–brain barrier with subsequent T‐cell infiltration and proliferation. We advocate aggressive resection and long‐term surveillance for individuals with metastasis, especially higher‐grade neoplasms that receive radiotherapy.     

Usefulness of T2*-weighted MR sequence for the diagnosis of subfrontal schwannoma

Subfrontal schwannomas are rare tumors that are usually diagnosed during surgery. They are often misdiagnosed as meningioma or esthesioneuroblastoma because of their similar clinical and radiological features. We report a case of schwannoma arising from the floor of the anterior cranial fossa that had radiological features similar to that of meningioma. However, T2*-weighted MR imaging revealed multiple foci of low signal intensities within the tumor related to microbleeds, which suggested a diagnosis of schwannoma that was confirmed by histopathology. This case report demonstrates the usefulness of T2*-weighted sequence in distinguishing meningioma from schwannoma, especially in cases where the tumor has an unusual location.     

Anaplastic meningioma: Progression from atypical and chordoid morphotype with morphologic spectral variation at recurrence

The current WHO 2007 classification divides meningiomas into a 3‐grade prognostic hierarchy. Recent literature evokes two pathways to disease progression in meningiomas akin to a comparable paradigm in gliomas, but without similar prognostic connotation: de novo anaplastic meningioma (better prognosis), and transformed meningioma (worse prognosis). We present two adult cases of transformed meningiomas that display a spectrum of morphologic progression. Case 1 at presentation showed a random admixture of meningothelial, atypical and anaplastic meningioma. The tumor recurred as anaplastic meningioma. Case 2 presented as a chordoid meningioma, but recurred as anaplastic meningioma mainly at the invasive front in transition with residual chordoid pattern. Of interest, portions of tumor also showed papillary configuration. In accordance with the dire prognosis for anaplastic meningioma, both patients succumbed to their disease within 2 months of recurrence. The present study highlights two main points: First, that proper recognition of focal high‐grade areas in a heterogeneous low‐grade meningioma (case 1) provides critical morphologic clues to spatial histologic progression and predicts aggressive biologic behavior, as evidenced by progression to frankly anaplastic meningioma at recurrence. Second, the presence of papillary in addition to anaplastic areas, in the recurrence of a previously diagnosed chordoid meningioma supports the ostensibly heightened transforming potential of grade II meningiomas, but also reflects on the morphologic heterogeneity of high‐grade meningiomas, and their potentially diverse pathways of progression. We propose that grading of meningiomas as outlined by WHO is of more critical prognostic import than histologic sub‐typing, and must include a thorough survey of the tumor‐brain interface. Future molecular genetic correlates, akin to those characterized in gliomas, could help stratify prognostic subcategories to refine meningioma grading, and govern optimal therapeutic strategies.     

Pineal chordoid meningioma complicated by repetitive hemorrhage during pregnancy: Case report and literature review

Chordoid meningioma is an uncommon variant of meningioma, and is very rarely found in the pineal region. We report a case of pineal region chordoid meningioma occurring in a young woman complicated by repetitive hemorrhages in the setting of pregnancy. A 23‐year‐old woman, 28 weeks pregnant, was transferred to our hospital for further management of a multi‐septated, hemorrhagic pineal region mass and hydrocephalus. MRI revealed a heterogeneous T2‐hyperintense lesion measuring 1.7 × 1.7 cm in the pineal gland. Resection of the tumor through an occipital transtentorial approach was performed. Histopathologic examination of the lesion confirmed the diagnosis of chordoid meningioma demonstrating cords and clusters of eosinophilic cells with rare cytoplasmic vacuolation arranged in a mucinous stroma. Additionally, there was abundant lymphoplasmacytic infiltration within the tumor. The details of this case are presented with a review of the literature.     

Intractable epilepsy due to a rosette‐forming glioneuronal tumor with a dysembryoplastic neuroepithelial background

A rosette‐forming glioneuronal tumor (RGNT) was initially reported as an infratentorial tumor that comprised both small neurocytic rosettes and astrocytic components. However, a few studies have reported supratentorial RGNTs arising in the cerebral hemispheres. Here, we report an unusual case involving a 9‐year‐old boy with a supratentorial RGNT who presented with intractable epilepsy and behavioral changes. Brain MRI revealed a well‐circumscribed space‐occupying lesion with septae in the right inferomedial parietal lobe. Electroencephalography showed multifocal spikes over the right frontal, temporal and parietal regions. The seizure frequency decreased dramatically after tumorectomy. Histopathological examination revealed prominent neurocytic rosette formation appearing with the specific glioneuronal element of a dysembryoplastic neuroepithelial tumor (DNT). Although the pathogenesis has not been elucidated, a supratentorial RGNT presenting with epilepsy may exhibit a rosette component, which is the major feature of this tumor, against the background of a specific glioneuronal element mimicking DNT. However, RGNT arising in regions other than the fourth ventricle is rare, and the pathogenesis of epilepsy due to RGNT has not been fully elucidated. Further clinical and histological studies are required to understand the pathology underlying epilepsy caused by RGNT.     

Primary rhabdoid tumor with low grade glioma component of the central nervous system in a young adult

In the CNS, primary tumors with rhabdoid components are classified as atypical teratoid/rhabdoid tumor, rhabdoid meningioma or rhabdoid glioblastoma. The authors present a young adult patient with supratentorial rhabdoid tumor incidentally found after head trauma as a small pre‐existing lesion in the parahippocampal gyrus. MRI demonstrated an area of hypointensity on T1‐weighted images and hyperintensity on T2‐weighted and fluid attenuated inversion recovery images. A serial MR scan revealed no change 3 months after the initial examination but drastic changes at 6 months. As the tumor and accompanying intratumoral hemorrhage enlarged rapidly, resection of the tumor was performed. Histopathology revealed that the main component of the tumor was typical rhabdoid cells with some necrotic areas. There were also pathological features consistent with oligoastrocytoma. The specimen had neither vascular proliferation usually seen in high‐grade glioma nor the meningothelial pattern that suggests meningioma. Immunohistochemical findings revealed that cells were strongly positive for vimentin, epithelial membrane antigen and INI‐1 antibody throughout the specimen. Further, monosomy 22 was detected by fluorescence in situ hybridization. The tumor was finally thought to be an unclassifiable primitive rhabdoid tumor with oligoastrocytoma that arose in the CNS. The patient died within 5 months of detection of the tumor, regardless of surgical resection, radiotherapy and chemotherapy.     

Intrameningioma metastasis: A case-based literature review

A tumor-to-tumor metastasis inside a meningioma is a rare phenomenon. Malignant neoplasms of the breast and lung are the most common primary tumors. Other sites of origin include prostate, renal and gastric neoplasms. The included case files were retrieved from the medical records of the University Hospital of Crete, Greece. A review of the literature was conducted in March 2020 via PubMed. Relevant search results were few. We report a case of a 66-year-old female, with known Small Cell Lung Cancer, who presented with left-sided hemiparesis. The Magnetic Resonance Imaging scan revealed a right frontal extra-axial mass. The patient underwent a craniotomy and a gross total removal of the tumor. Histological examination of the excised mass revealed metastatic adenocarcinoma deposits inside a meningioma: tumor-to-tumor metastasis. Reviewing the available literature, it has been hypothesized that the following factors play a role in the pathophysiology of this phenomenon: progesterone and estrogen receptors, cell-to-cell adhesion molecules, rich vascularization, favorable metabolic, micro-and immunological environment. Meningiomas seem to be the most common type of intracranial neoplasm to host a metastasis. There is a difference between tumor-to-tumor metastasis and collision tumors. The former implies a recipient role of the host tumor, and the latter refers to a co-localization of two different tumors that grow into one another, both being in the same organ. Tumor-to-tumor brain metastasis is a well-described phenomenon but with unclear pathophysiology. Deeper knowledge could be beneficial for its management.