Dural lesions mimicking meningiomas

Dural-based large B-cell lymphoma masquerading as a tentorial meningioma

A 53-year-old woman presented with a 2-week history of headache and vertigo. Computed tomography revealed a hyperdense tumor, measuring 30 × 31 × 36 mm in diameter, in the anteromedial parts of the cerebellar hemispheres. Cerebral magnetic resonance imaging 10 days later revealed an apparent extra-axial tumor with broad attachment to the medial tentorium cerebelli and rapid growth to a diameter of 40 × 41 × 46 mm. Cerebral angiography revealed no obvious feeding vessels or tumor stains. The patient underwent biopsy through the left occipital transtentorial route. The histological appearance was consistent with diffuse large B-cell lymphoma. Intracranial lymphoma may present as a dural tumor that mimics a meningioma. Rapid tumor growth incongruous with benign meningiomas should be assumed to be possible lymphoma, and prompt biopsy should be performed.

Primary central nervous system marginal zone lymphoma

Marginal zone lymphoma (MZL) is the most common indolent lymphoma primarily arising in the central nervous system (CNS). To date, 207 cases of primary CNS MZL (PCNSMZL) were published, mostly as single case reports or small case series. It most commonly presents as extra-axial dural-based masses, more frequently in middle-aged women, displaying an insidious onset, with a long history of symptoms preceding the diagnosis. PCNSMZL can be radiographically mistaken for meningioma. PCNSMZL consists of CD20+ , CD3- small B lymphocytes with varying degrees of plasmacytic differentiation and low proliferation index. Trisomy 3, but not MALT1 or IgH translocation, is a common genetic abnormality. Other recurrent genetic abnormalities involve TNFAIP3 and NOTCH2. Ethiopathogenesis was poorly investigated. Due to its rarity, standard of care remains to be defined; it exhibits an excellent prognosis after varied treatments, such as surgery, radiotherapy, chemotherapy or their combinations. Nevertheless, each treatment should be considered after an accurate analysis of overtreatment risk. Short follow-up is a major limitation in reported PCNSMZL cases, which restrains our knowledge on long-term results and iatrogenic sequels. This review was focussed on presentation, differential diagnoses, pathological findings, treatment options and clinical outcomes of PCNSMZL; recommendations for best clinical practice are provided.

Multiple and recurrent intracranial pseudolymphoma mimicking multiple skull base meningioma, a case report

INTRODUCTION AND IMPORTANCE

Primary central nervous system (CNS) lymphomas (PCNSLs) comprise a heterogeneous subset of intracranial disorders, predominantly of the intraparenchymal high-grade non-Hodgkin's lymphoma. Intracranial pseudolymphoma represents an exceedingly rare entity; as few as 3 reports in the English literature. We describe the first multiple large intracranial pseudolymphomata leading to increased intracranial pressure, visual loss, and recurrence during a short while. It also represents the first report of intracranial pseudolymphoma presented as a skull base tumor.

CASE PRESENTATION

We describe a 67-year-old female suffering from left-sided loss of visual acuity, headache, nausea, vomiting, and improper balance. Axial brain computed tomography (CT) scan revealed an isodense anterior interhemispheric mass lesion with surrounding edema in both frontal lobes. T1 and T2 weighted magnetic resonance imaging (MRI) and T1 weighted with gadolinium injection revealed two extra-axial isointense dural-based mass lesions with homogenous enhancement compressing both frontal lobes. The morphologic findings favored B cell pseudolymphoma and meningeal B cell lymphoid hyperplasia. One year later, she developed headaches, disorientation, and progressive meaningless speech lasting 2 months. Subsequent MRI demonstrated the rapid growth of the lesion of the lesser sphenoid wing and recurrence of the lesion at the same site of surgery, thereby undergoing revision surgery in which both tumors were maximally resected using a pterional approach.

CLINICAL DISCUSSION

Intracranial pseudolymphoma remains exceedingly rare, and despite its benign cellular nature, it may proliferate and recur quickly.

CONCLUSION

Intracranial pseudolymphoma should always be considered a rare but potentially differential diagnosis leading to the intraventricular lesion.

Meningioma and Other Meningeal Tumors

Meningiomas develop from meningothelial cells and approximately account for more than 30 percent of central nervous system (CNS) tumors. They can occur anywhere in the dura, most often intracranially and at dural reflection sites. Half of the cases are usually at parasagittal/falcine and convexity locations; other common sites are sphenoid ridge, suprasellar, posterior fossa, and olfactory groove. The female-to-male ratio is approximately 2 or 3-1, and the median age at diagnosis is 65 years. Meningiomas are generally extremely slow-growing tumors; many are asymptomatic or paucisymptomatic at diagnosis and are discovered incidentally. Clinical manifestations, when present, are influenced by the tumor site and by the time course over which it develops. Meningiomas are divided into three grades. Grade I represents the vast majority of cases; they are considered typical or benign, although their CNS location can still lead to severe morbidity or mortality, resulting in a reported ten-year net survival of over 80%. Atypical (WHO grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases. They show a tendency for recurrence and malignant degeneration with a relevant increase in tumor cell migration and surrounding tissue infiltration; ten-year net survival is reported over 60%. The anaplastic subtype (WHO III) represents only 1-3% of cases, and it is characterized by a poor prognosis (ten-year net survival of 15%). The treatment of choice for these tumors stands on complete microsurgical resection in case the subsequent morbidities are assumed minimal. On the other hand, and in case the tumor is located in critical regions such as the skull base, or the patient may have accompanied comorbidities, or it is aimed to avoid intensive treatment, some other approaches, including stereotactic radiosurgery and radiotherapy, were recommended as safe and effective choices to be considered as a primary treatment option or complementary to surgery. Adjuvant radiosurgery/radiotherapy should be considered in the case of atypical and anaplastic histology, especially when a residual tumor is identifiable in postoperative imaging. A "watchful waiting" strategy appears reasonable for extremely old individuals and those with substantial comorbidities or low-performance status, while there is a reduced threshold for therapeutic intervention for relatively healthy younger individuals due to the expectation that tumor progression will inevitably necessitate proactive treatment. To treat and manage meningioma efficiently, the assessments of both neurosurgeons and radiation oncologists are essential. The possibility of other rarer tumors, including hemangiopericytomas, solitary fibrous tumors, lymphomas, metastases, melanocytic tumors, and fibrous histiocytoma, must be considered when a meningeal lesion is diagnosed, especially because the ideal diagnostic and therapeutic approaches might differ significantly in every tumor type.

Imaging Characteristics of Meningiomas

Contemporary neuroimaging of meningiomas has largely relied on computed tomography, and more recently magnetic resonance imaging. While these modalities are frequently used in nearly all clinical settings where meningiomas are treated for the routine diagnosis and follow-up of these tumors, advances in neuroimaging have provided novel opportunities for prognostication and treatment planning (including both surgical planning and radiotherapy planning). These include perfusion MRIs, and positron emission tomography (PET) imaging modalities. Here we will summarize the contemporary uses for neuroimaging in meningiomas, and future applications of novel, cutting edge imaging techniques that may be routinely implemented in the future to enable more precise treatment of these challenging tumors.

Pachymeningitis in Biopsy-Proven Sarcoidosis

Background and Objectives

Meningeal inflammation is one of the most common manifestations of neurosarcoidosis, occurring in 16%–69% of affected patients. While the clinical and radiographic features of leptomeningitis in neurosarcoidosis are well known, those of pachymeningitis are far less clear. Our primary aim was to study the clinicoradiographic features of pachymeningeal involvement in neurosarcoidosis and its evolution over time in response to treatment.

Methods

Patients with a diagnosis of neurosarcoidosis seen at Emory University (January 2011–August 2021) were included if pachymeningeal involvement was evident by MRI and the patient's sarcoidosis was pathologically confirmed (from a CNS or non-CNS site).

Results

Twenty-six of 215 (12.1%) patients with neurosarcoidosis qualified for inclusion. Pathologic confirmation came from CNS tissue in 50%. The median age of onset was 43.5 years; most were male (16/26, 61.5%). Symptoms were primarily related to pachymeningitis in 20/26 (76.9%). Headache (19/26, 73.1%), visual dysfunction (12/26, 46.2%), and seizures (7/26, 26.9%) were the most common symptoms. All patients had cranial pachymeningitis; only a single patient undergoing spinal imaging (1/11, 9.1%) had spinal pachymeningitis. The falx cerebri (16/26, 61.5%) was the most commonly affected dural structure, but the anterior and middle cranial fossae and tentorium cerebelli were frequently involved (12/26 each, 46.2%). The pachymeningeal lesions were unifocal (11/26, 42.3%) or multifocal (15/26, 57.7%) in distribution, nodular morphologically (23/25, 92.0%), and homogeneously enhancing (24/25, 96.0%). Symptomatic improvement occurred with steroids initially in 22/25 (88.0%). Ultimately, 23/26 (88.5%) required initiation of steroid-sparing immunosuppressants, including 8/26 (30.8%) eventually undergoing TNF inhibition. Pachymeningeal relapses occurred in 7/26 (26.9%). The median clinical follow-up was 48 months. The median modified Rankin scale score at last follow-up improved to 1.0 from 2.0 at presentation.

Discussion

Pachymeningitis due to sarcoidosis often presents with headaches, visual dysfunction, and seizures; it usually affects the dura of the falx cerebri, anterior and middle cranial fossae, and tentorium cerebelli and tends to require steroid-sparing immunosuppressants. It has the potential to relapse, but the prospect for recovery is good.

Dural lymphoma misdiagnosed as subdural hematoma following head trauma after an episode of syncope

Primary dural lymphoma is a rare subtype of primary central nervous system lymphoma. Primary dural lymphoma may be radiologically misdiagnosed as it shares similar imaging characteristics with several pathologies, including meningiomas and subdural or epidural hematomas. We present a patient who was originally diagnosed with a subdural hematoma following a syncopal episode on computed tomography. Follow-up magnetic resonance imaging of the brain demonstrated heterogeneously enhancing dural-based mass overlying the left frontoparietal convexity associated with bidirectional dural tails, suggestive of a malignant meningioma. Neurosurgical histopathology revealed marginal zone B-cell lymphoma. This case represents the potential difficulty in diagnosing primary dural lymphoma, especially in the setting of uncertain clinical history and obscured imaging features.

Intracranial Rosai Dorfman Disease Presented With Multiple Huge Intraventricular Masses: A Case Report

Introduction

Rosai-Dorfman disease (RDD) usually presents with painless cervical lymphadenopathy during the two first decades of life, with or without extranodal involvement. Exclusive extranodal manifestation, and especially central nervous system (CNS) involvement, is uncommon. The etiology remains unknown and definitive diagnosis is based on characteristic histopathological and immunohistochemical features showing S100(+) CD1a(−) RDD type histiocytes with emperipolesis. Most CNS cases are dural-based masses.

Case Presentation

Herein, we present a case of RDD in an 8-year-old boy, who presented with multiple huge intraventricular masses.

Conclusion

Regarding rare CNS involvement and lack of established evidence-based therapeutic approaches, reports of any individual case can supply further beneficial data concerning treatment approaches and long-term effectiveness of therapeutic strategies.

Use of advanced neuroimaging and artificial intelligence in meningiomas

Anatomical cross‐sectional imaging methods such as contrast‐enhanced MRI and CT are the standard for the delineation, treatment planning, and follow‐up of patients with meningioma. Besides, advanced neuroimaging is increasingly used to non‐invasively provide detailed insights into the molecular and metabolic features of meningiomas. These techniques are usually based on MRI, e.g., perfusion‐weighted imaging, diffusion‐weighted imaging, MR spectroscopy, and positron emission tomography. Furthermore, artificial intelligence methods such as radiomics offer the potential to extract quantitative imaging features from routinely acquired anatomical MRI and CT scans and advanced imaging techniques. This allows the linking of imaging phenotypes to meningioma characteristics, e.g., the molecular‐genetic profile. Here, we review several diagnostic applications and future directions of these advanced neuroimaging techniques, including radiomics in preclinical models and patients with meningioma.

Intracranial neuroendocrine tumour simulating meningioma for several years: an overview of diagnosis and treatment

Metastatic neuroendocrine tumour (NET) to brain has been reported in 1.5–5% of patients with NETs. Differentiation between intracranial NET metastasis and meningiomas can cause a diagnostic dilemma. We present a symptomatic case of a 66-year-old male with a history of left-sided skull base mass. The diagnosis of a meningioma was made based on the MRI findings and clinical presentation. The patient received radiation and the mass remained stable on serial MRI images at follow-up visits. Five years after his initial presentation, the patient’s mass showed further growth. He also complained of worsening of his recent diagnosis of irritable bowel syndrome and fluctuations in his blood pressure. Surgical resection was performed, and histopathological features were consistent with moderately differentiated neuroendocrine tumour. Further evaluation with 68 Gallium-DOTATATE positron emission-computed tomography (Ga-68 PET/CT) showed metastatic disease involving the bones, lymph nodes, and liver without convincing evidence of the location of primary malignancy within the bowel loops or the pancreas. The patient was started on combination of capecitabine and temozolomide with partial response and significant improvement of his symptoms. This case highlights the clinical and radiological behaviour of intracranial NET that can mimic the diagnosis of meningioma.

Inflammatory pseudotumor simulating a jugular foramen meningioma: case report, technical video and literature review

Inflammatory pseudotumor (IP) is a non-neoplastic, reactive inflammatory process, of unknown etiology, characterized by a proliferation of connective tissue with an inflammatory infiltrate, most commonly involving the lungs and orbits. Primary intracranial inflammatory pseudotumor is an extremely rare entity often arising from the meningeal structures of the skull base. We reported an extremely rare case of a primary intracranial IP located in the cerebello-pontine angle, mimicking a jugular foramen meningioma. We further illustrated our microsurgical technique through a surgical video and performed a review of the pertinent scientific literature. The patient underwent gross total microsurgical resection of the tumor mass through a left retrosigmoid approach. Intraoperative neuro-monitoring of VII-VIII cranial nerve complex and lower cranial nerve was performed, and thulium laser fibers were used as a tool for tumor debulking. Post-operatively, patient neurological symptoms recovered. Histopathological studies showed dense infiltrate of T and B cells lymphocytes and epithelioid granulomas, compatible with the diagnosis of inflammatory pseudotumor. Post-operative, MRI scans showed complete tumor resection. Patient underwent a 3-month oral corticosteroid therapy showing no signs of recurrence at the radiological follow-up. Primary intracranial inflammatory pseudotumors are very rare pathological entities that can mimic extra-axial tumors, and should take into consideration as a potential differential diagnosis. Complete microsurgical resection in combination with other treatments (steroids therapy, radiotherapy) is the most common treatment of choice and in associated to good outcome and low rate of recurrence.

Cervical solitary fibrous tumor: case report and literature review

Solitary fibrous tumors (SFTs) are rare neoplasms in the spinal canal. There are few studies addressing SFT/hemangiopericytomas with no distinctive clinical characteristics, no conclusive radiological findings or even a well-defined best treatment strategy. We described a rare case of cervical SFT/hemangiopericytomas in a young patient with spinal cord compression. There are many differential diagnoses for spinal dural-based masses of which meningiomas are the most common. Surgeons and oncologists should be aware of differentials of dural-based masses in the spinal cord for surgical decision making and to guide treatment.

Meningioma: not always a benign tumor. A review of advances in the treatment of meningiomas

Meningiomas are the most common primary intracranial tumors. The majority of meningiomas are benign, but they can present different grades of dedifferentiation from grade I to grade III (anaplastic/malignant) that are associated with different outcomes. Radiological surveillance is a valid option for low-grade asymptomatic meningiomas. In other cases, the treatment is usually surgical, aimed at achieving a complete resection. The use of adjuvant radiotherapy is the gold standard for grade III, is debated for grade II and is not generally indicated for radically resected grade I meningiomas. The use of systemic treatments is not standardized. Here we report a review of the literature on the clinical, radiological and molecular characteristics of meningiomas, available treatment strategies and ongoing clinical trials.

Case report of primary dural lymphoma mimicking a cerebellar meningioma and brief review of literature

Primary dural lymphoma (PDL) is an extremely rare subtype of primary central nervous system lymphoma arising from the dura mater in absence of systemic disease. The most common histological type is the low-grade marginal zone lymphoma, whereas high-grade lymphomas are unusual. We present a case of primary diffuse large B-cell lymphoma, presenting as PDL in the posterior fossa, originating from the dura mater of the petrous bone covering the surface of the left cerebellum, a location not previously described. A 65-year-old woman presented with sudden onset of severe dizziness was admitted in otolaryngology department then transferred to neurosurgery ward. CT scan revealed a large lesion involving left cerebellum, subsequent MRI of the brain demonstrated an enhancing mass suggestive for petrous bone meningioma. The tumor was excised, and the histopathological examination unexpectedly revealed a diffuse large B-cell lymphoma. The patient received postoperative chemoradiotherapy. 20 months after surgery a good outcome was registered. Due to the rarity of primary dural lymphomas no standard treatment is available, however, gross total or subtotal resection followed by adjuvant therapy seems to be a good choice to manage the pathology.

Pathological Spectrum of Dura-Based Nonmeningothelial Lesions: 5 Years' Experience from a Tertiary Care Centre

Introduction Nonmeningothelial lesions arising from the dura comprise a wide spectrum of pathologies ranging from neoplastic to infective etiologies. They have overlapping clinical and radiologic findings necessitating histopathological evaluation for the final diagnosis which in turn dictates management and prognosis. Therapeutic strategies are different for each of the lesion. There is scarcity of large case series detailing clinicopathological spectrum of dura-based nonmeningothelial lesions.

Materials and Methods In this study, we analyzed the neuropathological spectrum of dura-based nonmeningothelial lesions diagnosed over a period of 5 years in our tertiary care center.

Results There were 79 cases of dura-based nonmeningothelial lesions constituting 7.3% of all dura-based lesions (age range: 2–75 years; M:F = 2:3). Basal region was more frequently involved than the convexities. On histopathology, neoplastic lesions predominated (92.4%) and included in order of frequency solitary fibrous tumor/hemangiopericytoma (35.6%), gliomas (27.4%), metastasis (27.4%), mesenchymal tumors (4%), primitive neuroectodermal tumor (2.73%), and medulloblastoma (2.73%). Infective lesions were less frequent (7.6%), included fungal infections and Rosai-Dorfman disease.

Conclusion Awareness of the spectrum of nonmeningothelial dural lesions is useful for pathologists as well as the treating surgeon.

Intracranial Solitary Fibrous Tumor of the Skull Base: 2 Cases and Systematic Review of the Literature

BACKGROUND

Intracranial solitary fibrous tumors (ISFTs) are rare neoplasms of mesenchymal origin that originate from the meninges. ISFTs of the skull base can be challenging to treat, as resection can be complicated by skull base anatomy. We present 2 cases of ISFT, the first manifesting with compressive cranial neuropathy from Meckel cave involvement and the second a posterior fossa lesion causing symptomatic hydrocephalus.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed database was queried with title/abstract keywords "intracranial," "solitary fibrous tumor," "hemangiopericytoma," "SFT," and "HPC." Search results were reviewed to exclude cases not involving the skull base. References from all selected articles were reviewed for potential additional cases. Patient demographic and clinical data from 58 identified skull base cases were collected for qualitative synthesis.

RESULTS

Visual disturbances were the most common presenting symptom (30 cases, 52%) followed by headache (22 cases, 38%). The most common site of involvement was the sellar/parasellar region (18 cases, 31%) followed by middle fossa/temporal bone (14 cases, 24%). Resection was performed in 55 cases; gross total resection was reported in 26 cases (45%) and subtotal resection was reported in 21 cases (36%). Tumor recurrence was documented in 15 cases (26%) with median and mean follow-up periods of 16 and 29.9 months, respectively.

CONCLUSIONS

We discuss presentation, imaging, histopathology, and management considerations for ISFTs while highlighting the potentially complex nature of skull base lesions and need for multidisciplinary approach to treatment.

Dural-based lesions: is it a meningioma?

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Solitary Plasmacytoma with Amyloid - An Unusual Dural-Based Lesion

Solitary plasmacytoma of the dura without systemic involvement are extremely rare lesions, with <15 cases reported in the literature. Among these, ours is the second case to show the presence of amyloid. Fifty-year-old male had presented with headache, sudden onset right-sided weakness, and vomiting. Magnetic resonance imaging revealed an extra-axial mass in the left fronto-parietal region measuring 10 cm × 8.7 cm × 3.9 cm, suggestive of meningioma. The left fronto-parietal craniotomy was performed and multiple tissue bits aggregating to 10 cm × 8.5 cm × 2 cm along with thinned out membrane-like bit of calvarium was sent for pathologic examination. H and E stained sections showed sheets of plasmacytoid cells along with amyloid, which showed apple-green birefringence on Congo red staining. On immunohistochemistry, tumor cells were positive for CD38, CD138, showed kappa light chain restriction and were negative for CD45, CD34. Hence, it was diagnosed as a plasma cell neoplasm. Further work-up with whole-body positron-emission tomography scan revealed no systemic involvement. Dural-based lesions can mimic meningioma radiographically as well as intraoperatively. Histopathological examination unveils the diagnosis, to guide appropriate therapeutic regimens.

The Current State of Radiomics for Meningiomas: Promises and Challenges

Meningiomas are the most common primary tumors of the central nervous system. Given the fact that the majority of meningiomas are benign, the preoperative risk stratification and treatment strategy decision-making highly rely on the conventional subjective radiologic evaluation. However, this traditional diagnostic and treatment modality may not be effective in patients with aggressive-growing tumors or symptomatic patients with potential risk of recurrence after surgical resection or radiotherapy, as this passive “wait and see” strategy could miss the optimal opportunity of intervention. Radiomics, a new rising discipline, translates high-dimensional image information into abundant mathematical data by multiple computational algorithms. It provides an objective and quantitative approach to interpret the imaging data, rather than the subjective and qualitative interpretation from relatively limited human visual observation. In fact, the enormous amount of information generated by radiomics analyses provides radiological to histopathological tumor information, which are visually imperceptible, and offers technological basis to its applications amid diagnosis, treatment, and prognosis. Here, we review the latest advancements of radiomics and its applications in the prediction of the pathological grade, pathological subtype, recurrence possibility, and differential diagnosis of meningiomas, and the potential and challenges in general clinical applications. In this review, we highlight the generalization of shared radiomic features among different studies and compare different performances of popular algorithms. At last, we discuss several possible aspects of challenges and future directions in the development of radiomic applications in meningiomas.

Neuroimaging features of CNS histiocytosis syndromes

Histiocytosis syndromes (HS) are group of heterogeneous disorders characterized by abnormal accumulation and infiltration of histiocytes, cells derived from hematopoietic cells of monocyte/macrophage lineage. Overall these disorders are rare. When they do occur they involve many organ systems including the central nervous system (CNS). While imaging findings can provide important clues, diagnosis of this disorder is challenging and definitive diagnosis often necessitates pathologic examination. In this review, we describe imaging features of HS involving the CNS, with the aim to increase our understanding of these disorders. The entities discussed in this review will include: Langerhans cell histiocytosis (LCH), Rosai-Dorfman Disease (RDD), Erdheim Chester Disease (ECD), hemophagocytic lymphohistiocytosis (HLH), and crystal-storing histiocytosis (CSH).

Intracranial Metastases from Prostate Carcinoma: Classification, Management, and Prognostication

BACKGROUND

Prostate carcinomas rarely metastasize to the central nervous system but, when they do, dural localizations are as common as and far more aggressive than intraparenchymal ones. Those metastases can be further classified according to their extension toward the subdural or extradural space and can frequently simulate other pathologic conditions including chronic subdural hematomas, abscess, and primary bone tumors. Beside the challenges of the preoperative differential diagnostic and complexity of surgical planning and operative excision, subdural metastases seem to carry a much poorer prognosis.

METHODS

A series of consecutive patients admitted during a 12-year period through our oncall pathway for subdural/extradural collections or intraparenchymal lesions found, on histologic analysis, to represent intracranial prostate cancer metastases was retrospectively reviewed.

RESULTS

A total of 19 patients were included, but only 3 were diagnosed with small cell prostate carcinoma, while the majority had a primary prostate adenocarcinoma. Metastases could be classified as pure subdural space lesions, dural-based lesions, extradural/bony lesions, and pure intraparenchymal lesions. All patients with subdural metastases and 3 out of 5 patients with dural-based lesions required an emergency intervention due to rapidly deteriorating neurologic status. The mean follow-up in our series was 37 months; only subdural localizations had a remarkably unfavorable outcome.

CONCLUSIONS

Supported by our experience and the review of the literature, we suggest that a low threshold for contrast-enhanced computed tomography/magnetic resonance imaging is advisable in case of suspicious subdural collection, even in an emergency setting, for patients with previous medical history of prostate cancer.

Current status of PET imaging in neuro-oncology

Over the past decades, a variety of PET tracers have been used for the evaluation of patients with brain tumors. For clinical routine, the most important clinical indications for PET imaging in patients with brain tumors are the identification of neoplastic tissue including the delineation of tumor extent for the further diagnostic and therapeutic management (ie, biopsy, resection, or radiotherapy planning), the assessment of response to a certain anticancer therapy including its (predictive) effect on the patients’ outcome and the differentiation of treatment-related changes (eg, pseudoprogression and radiation necrosis) from tumor progression at follow-up. To serve medical professionals of all disciplines involved in the diagnosis and care of patients with brain tumors, this review summarizes the value of PET imaging for the latter-mentioned 3 clinically relevant indications in patients with glioma, meningioma, and brain metastases.

Primary intracranial leiomyosarcoma in an immunocompetent patient: Case report with emphasis on imaging features

RATIONALE

Primary intracranial leiomyosarcoma (LMS) is an extremely rare tumor in the central nervous system (CNS), and usually seen in immunocompromised individuals. Only a few cases of primary intracranial LMS have been documented in the literature and no study focused on their MRI findings. We reported a case of primary intracranial leiomyosarcoma in a immunocompetent patient and review its imaging features.

PATIENT CONCERNS

A 20-year-old female was admitted to our hospital, complaining with nausea, weight loss and progressive headache in recent 2 years.

DIAGNOSIS

The magnetic resonance imaging scan of the brain revealed a large well-defined extra-cerebral mass adherent to left temporal meninges. The mass was iso-intense on T1-weighted images (T1WI), lightly iso to hypointense on T2-weighted images (T2WI) and enhanced uniformly with contrast medium. The preoperative diagnosis is meningioma.

INTERVENTIONS

A left craniotomy was performed for the complete resection of the mass.

OUTCOMES

The lesion was diagnosed via surgical histopathology and immunochemistry as leiomyosarcoma. No evidence of recurrence and complications were found in the following 13 months.

LESSIONS

Primary intracranial leiomyosarcoma which has some special MR imaging features should be considered in the differential diagnosis of intracranial tumor.

A Rare Case of Isolated Intracranial Rosai-Dorfman Disease Mimicking Optic Nerve Meningioma: A Case Report and Literature Review

Sinus histiocytosis with massive lymphadenopathy, or Rosai–Dorfman disease (RDD), was first described in 1969 as a reactive condition of unknown etiology that is characterized by a proliferation of histiocytes exhibiting emperipolesis of both lymphocytes and plasma cells. It usually presents with painless cervical lymphadenopathy either with or without extranodal manifestations. Intracranial involvement of this disease is extremely rare. Intracranial RDD occurs in <5% of all patients with extranodal disease. Here, we report a case of RDD with isolated intracranial involvement. A 67-year-old male presented with a long-standing headache, retro-ocular pain, and progressive visual loss of the left eye. Magnetic resonance imaging showed features of optic nerve meningioma. The histopathology revealed sheets of histiocytes displaying emperipolesis. These histiocytes were S100 positive; however, a CD1a and epithelial membrane antigen were negative.

"The Subdural Collection" a Great Simulator: Case Report and Literature Review

Prostate carcinoma rarely develops intracranial metastasis. In case it does, the dura is the most affacted area. In general, brain computed tomography (CT) findings mimic subdural hematoma making surgery challenge. We report the case of a 52-year-old male, presented as an emergency with a month history of headache, progressive temporospatial disorientation, mental confusion, and abrupt consciousness deterioration up to coma occurring few hours prior admission. An urgent brain CT scan showed a subdural collection in favor of a chronic subdural hematoma. The patient underwent surgery by standard burr hole, and surprisingly, peroperatively, there was a very bloody diffuse thickening of the dura without a real hematoma obliging to switch to a large fronto-temporoparietal craniotomy revealing a subdural mass that was completely removed. Histopathology disclosed a metastatic prostatic carcinoma confirming that such a subdural collection could behave as a great simulator. A contrast brain CT scan, is advisable, even in emergency, in selected case, with atypical images finding, especially if, a malignant disease is already known; the former could be of great help in the differential diagnosis and the best prompt management.

Diagnostic challenges in meningioma

Advances in molecular profiling and the application of advanced imaging techniques are currently refreshing diagnostic considerations in meningioma patients. Not only technical refinements but also sophisticated histopathological and molecular studies have the potential to overcome some of the challenges during meningioma management. Exact tumor delineation, assessment of tumor growth, and pathophysiological parameters were recently addressed by "advanced" MRI and PET. In the field of neuropathology, high-throughput sequencing and DNA methylation analysis of meningioma tissue has greatly advanced the knowledge of molecular aberrations in meningioma patients. These techniques allow for more reliable prediction of the biological behavior and clinical course of meningiomas and subsequently have the potential to guide individualized meningioma therapy. However, higher costs and longer duration of full molecular work-up compared with histological assessment may delay the implementation into clinical routine.This review highlights the diagnostic challenges of meningiomas from both the neuroimaging as well as the neuropathological side and presents the latest scientific achievements and studies potentially helping in overcoming these challenges. It complements the recently proposed European Association of Neuro-Oncology guidelines on treatment and diagnosis of meningiomas by integrating data on nonstandard imaging and molecular assessments most likely impacting the future.

Supratentorial dural-based collision of cavernoma and meningioma: a case report

Background

Collision tumor is a very rare case of cerebral lesion. Approximately 50 reports of intracranial collision tumors were described in the literature. We present a case of supratentorial dural-based convexity collision tumor radiologically mimicking cavernous malformation and composed of cavernous malformation and meningioma.

Case presentation

The case presents a 63-year-old female having MR findings such as hemorraged supratentorial dural-based mass with “popcorn” signs and hemosiderin deposits. The patient underwent craniotomy and evacuation of the subdural hematoma with resection of the tumor mass. Histologically the lesion had signs of a cavernoma and meningioma. MRI in a year after surgery did not reveale residual tumor mass or recurrence.

Conclusions

Collision tumor is a very rare case. Preoperative diagnosis of a dural lesion is difficult and challenging. A neuroradiological differential diagnosis of similar cases needs focused attention.

Metastatic prostate cancer mimicking a subdural hematoma: A case report and literature review

Occurrences of metastatic prostate cancer imitating a subdural hematoma are limited to a small number of case reports, even though prostate cancer spreads to the dura more than other types of cancer. Here, we present the case of a 64 year-old male whose prostate carcinoma's metastasis mimicked a subdural hematoma, and he suffered a middle cerebral artery stroke. Prostate cancer's high rate of progression to the dura is disproportionate to its relatively low rate of brain metastasis. Furthermore, we explore the potential molecular implications of prostate cancer's propensity to spread to the dura.

A dural metastatic small cell carcinoma of the gallbladder as the first manifestation: a case report

Background

A dural metastasis is one of the essential differential diagnoses of meningioma. In general, carcinomas of the breast and lung in females and prostate in males have been the most commonly reported primary lesions of dural metastases. However, dural metastasis of gallbladder carcinoma is extremely rare. Here, we report a unique case of a dural matter metastasis of gallbladder carcinoma as the first manifestation, which was autopsy-defined as small cell carcinoma.

Case presentation

A 78-year-old man came to our hospital complaining of left hemianopia. Brain computed tomography (CT) revealed a sizeable parasagittal dural-based extra-axial tumor. However, the findings for meningioma were atypical by magnetic resonance imaging, suggesting a meningioma mimic. A contrast-enhanced CT scan of the abdomen revealed a large gallbladder carcinoma. The patient opted for the best supportive care and died 2 months later. The post-mortem examination revealed small cell carcinoma in gallbladder carcinoma. Moreover, an immunologically similar carcinoma was detected in the dural metastasis.

Conclusions

To the best of our knowledge, this is the first case of a dural metastasis of gallbladder small cell carcinoma. A systemic examination is essential for clinicians when atypical findings of meningioma are observed, suggesting a meningioma mimic. We present this rare case with a review of the literature.

Intracranial dural, calvarial, and skull base metastases

Metastatic disease to the intracranial dura, the calvarium, and the skull base is relatively uncommon but presents unique diagnostic and management challenges in the patient with cancer. Modern imaging techniques have facilitated the detection of intracranial tumor deposits, leading to increased incidence. While dural and calvarial metastases often present with nonspecific symptoms, skull base metastases present with distinct clinical syndromes dependent on the local neurovascular structures affected. Intracranial dural metastases can often be confused with meningioma and pose a diagnostic challenge, as well as significant neurologic morbidity, especially in the setting of hemorrhage. Surgical intervention may be helpful in selected patients for symptomatic relief as well as survival benefit. Management paradigms need to take into account the relative risks, benefits, and likely outcomes for each possible modality of treatment. Surgical excision is useful in many patients and in combination with radiation therapy can provide significant palliation. While medical therapy is rarely an initial therapy in these entities, it may be of added benefit dependent on the underlying tumor histology and prior treatment history. Occasionally treatment with curative intent is justified.

PET imaging in patients with meningioma-report of the RANO/PET Group

Meningiomas are the most frequent nonglial primary brain tumors and represent about 30% of brain tumors. Usually, diagnosis and treatment planning are based on neuroimaging using mainly MRI or, rarely, CT. Most common treatment options are neurosurgical resection and radiotherapy (eg, radiosurgery, external fractionated radiotherapy). For follow-up after treatment, a structural imaging technique such as MRI or CT is used. However, these structural imaging modalities have limitations, particularly in terms of tumor delineation as well as diagnosis of posttherapeutic reactive changes. Molecular imaging techniques such as PET can characterize specific metabolic and cellular features which may provide clinically relevant information beyond that obtained from structural MR or CT imaging alone. Currently, the use of PET in meningioma patients is steadily increasing. In the present article, we provide recommendations for the use of PET imaging in the clinical management of meningiomas based on evidence generated from studies being validated by histology or clinical course.

Meningioma mimics: five key imaging features to differentiate them from meningiomas

There are a wide variety of intracranial mass lesions, both benign and malignant, which can closely mimic meningioma on imaging. We present five characteristic imaging features that can alert the radiologist to consider other differential diagnoses. Of the five imaging characteristics that were rarely seen in meningiomas, but common and specific for meningioma mimics, absence of dural tail is the most common (83.7%). Homogeneous T2 hyperintensity or T2 hypointensity are seen in nearly half of meningioma mimics and osseous destruction and leptomeningeal extension are present in 40.5% and 21.6% of meningioma mimics, respectively. The distinction between meningioma and its mimics is important because a large portion of the meningioma mimics requires substantially different clinical and surgical management.

Primary diffuse large B-cell lymphoma of the dura with skull and scalp involvement: A case report and brief review of the literature

Primary dural lymphoma (PDL) refers to a lymphoma with epidural or subdural involvement and is a rare subtype of primary central nervous system lymphoma. Diffuse large B-cell lymphoma (DLBCL) presenting as PDL is extremely rare. The present study reports a case of PDL with skull and scalp involvement in a 56-year-old man. Magnetic resonance imaging (MRI) revealed that the tumor was located under the right parietal inner plate and was attached to the dura mater. Following contrast-enhanced MRI, markedly enhanced tumor signals were observed, and mild homogeneous enhancement was observed in the diploë and soft tissues under the scalp, near the parietal bone. Under general anesthesia, the patient underwent craniotomy and tumor resection. The postoperative pathological diagnosis was DLBCL. Tumors were additionally identified inside the skull and subcutaneous tissues. The patient was administered chemotherapy postoperatively, and the prognosis subsequent to the 4-year follow-up was favorable. Primary malignant lymphoma should be considered in the differential diagnosis of scalp masses and meningeal lesions. Early diagnosis and individualized treatment is closely associated with a favorable outcome.

A Man in His 40s With Headache, Lethargy, and Altered Mental Status

A man in his 40s presented with 1 month of worsening confusion, fatigue, and headache. Results from laboratory analyses were notable for a complete white blood cell count of 17 000/μL (31% blast cells), a platelet count of 76 000/μL, and a hemoglobin level of 16.6 g/dL. Imaging studies revealed a large mixed-attenuation subdural collection in the right frontal region with prominent mass effect. The patient underwent an emergency neurosurgical procedure. The differential diagnosis, pathologic findings, and diagnosis are discussed.

Dural metastasis masquerading as an en plaque meningioma

Metastatic adenocarcinoma mimicking meningioma is rare; and any metastatic lesion masquerading as an en plaque meningioma is extremely rare. We report the case of a 50-year-old female, who presented with headache and left hemiparesis for 1 month and on imaging showed a dural-based enhancing mass along the right hemisphere. The patient was operated with a working diagnosis of en plaque meningioma. Histopathology revealed metastatic adenocarcinoma. This report highlights an unusual radiological presentation of a metastatic lesion as dural based en plaque variety. Metastasis should be borne in mind for any en plaque lesion with rapid clinical progression.

Rapid Recurrence of a Benign Meningial Perineurioma

BACKGROUND

We describe a rare case of a rapidly recurring benign meningial-based perineurioma. Clinical, radiologic, and pathologic features of a rapidly recurring falxial perineurioma are described; the perineurioma was discovered incidentally in an 86-year-old woman.

CASE DESCRIPTION

Due to progressive gait disturbances and radiologically proven progression after a 3-year symptom-free interval, subtotal resection of a large falxial-based meningeal tumor was performed.

CONCLUSIONS

The pathologic examination confirmed the diagnosis of a perineurioma (World Health Organization grade I). Follow-up magnetic resonance tomography 5 months later due to neurologic deterioration revealed an abnormally rapidly growing and extensive local tumor recurrence. Due to the mass effect, reoperation was performed and adjuvant radiation of 20 Gy to the tumor bed was implemented thereafter. Meningeal-based perineuriomas of the central nervous system are extremely rare, and literature on proper management is scarce. Although histologic classification reveals a benign lesion, follow-up may be considered for this type of tumor.

Case Report: Primary dural based diffuse large B-Cell lymphoma in a 14 year-old boy

Primary dural lymphoma is a subentity of primary leptomeningeal lymphoma which represents 0.1% of all non-Hodgkin’s lymphomas. Only five cases have been reported so far. We report a very rare case of primary dural-based lymphoma in a 14 year-old boy presenting with mass effect. The patient was managed with excision of the lesion and removal of the involved bone. Post-operatively, the patient showed good recovery. He was then referred to the oncology unit for further chemo- and radiation therapy. A high index of suspicion should therefore be kept in order to diagnose the condition in a timely fashion and then plan for appropriate management since diffuse large cell lymphoma has a relatively benign clinical prognosis.

From the radiologic pathology archives: mass lesions of the dura: beyond meningioma-radiologic-pathologic correlation

Meningioma is the most common mass involving the dura, making it number one in the differential diagnosis for any dural-based mass; however, a variety of other neoplastic and nonneoplastic lesions also involve the dura. Knowledge of the dural anatomy can provide clues to the various processes that may involve this location. The neoplastic processes include both benign and malignant lesions such as hemangiopericytoma, lymphoma, solitary fibrous tumor, melanocytic lesions, Epstein-Barr virus-associated smooth muscle tumors, Rosai-Dorfman disease, and metastatic lesions. The nonneoplastic processes include infectious and inflammatory entities such as tuberculosis and sarcoid, which may mimic mass lesions. In some cases, neoplasms such as gliosarcoma may arise peripherally from the brain parenchyma, appearing dural-based and even inciting a dural tail. Many of these share similar computed tomographic, magnetic resonance imaging, and angiographic characteristics with meningiomas, such as a dural tail, increased vascularity, avid enhancement, and similar signal characteristics; however, knowledge of the patient's age, gender, and underlying conditions and certain imaging characteristics may provide valuable clues to recognizing these lesions. For example, in the population with human immunodeficiency virus infection, Epstein-Barr virus-associated smooth muscle tumors should be included in the differential diagnosis for dural-based lesions. The surgical course and prognosis for these lesions vary, and knowledge of the variety of lesions that involve the dura, their imaging appearances, and their clinical features assists in narrowing the radiologic differential diagnosis and optimizing patient treatment.