Intracranial metastasis or meningioma? An uncommon clinical diagnostic dilemma

Case report of a patient with an intraosseous meningioma presenting as possible metastasis from prostate cancer: Diagnostic dilemma and review of literature

Intraosseous meningiomas are a rare subtype of meningiomas representing approximately 2% of all cases. They can confound a diagnosis of other bone lesions including metastatic tumors. We present a case of a patient with prostate cancer who on staging workup was suspected to have a skull metastasis. Both bone scan and CT Head demonstrated a lesion in the right frontal calvarium. Surgical resection and pathology revealed an intraosseous meningioma. The patient was restaged as having localized prostate cancer and the was offered curative treatment for his malignancy. The case highlights the importance of obtaining tissue diagnosis in cases of radiographic isolated oligometastatic disease in patients with a known primary malignancy.

Innovation in Non-Invasive Diagnosis and Disease Monitoring for Meningiomas

Meningiomas are tumors of the central nervous system that vary in their presentation, ranging from benign and slow-growing to highly aggressive. The standard method for diagnosing and classifying meningiomas involves invasive surgery and can fail to provide accurate prognostic information. Liquid biopsy methods, which exploit circulating tumor biomarkers such as DNA, extracellular vesicles, micro-RNA, proteins, and more, offer a non-invasive and dynamic approach for tumor classification, prognostication, and evaluating treatment response. Currently, a clinically approved liquid biopsy test for meningiomas does not exist. This review provides a discussion of current research and the challenges of implementing liquid biopsy techniques for advancing meningioma patient care.

Unveiling a Biomarker Signature of Meningioma: The Need for a Panel of Genomic, Epigenetic, Proteomic, and RNA Biomarkers to Advance Diagnosis and Prognosis

Meningiomas are the most prevalent primary intracranial tumors. The majority are benign but can undergo dedifferentiation into advanced grades classified by World Health Organization (WHO) into Grades 1 to 3. Meningiomas' tremendous variability in tumor behavior and slow growth rates complicate their diagnosis and treatment. A deeper comprehension of the molecular pathways and cellular microenvironment factors implicated in meningioma survival and pathology is needed. This review summarizes the known genetic and epigenetic aberrations involved in meningiomas, with a focus on neurofibromatosis type 2 (NF2) and non-NF2 mutations. Novel potential biomarkers for meningioma diagnosis and prognosis are also discussed, including epigenetic-, RNA-, metabolomics-, and protein-based markers. Finally, the landscape of available meningioma-specific animal models is overviewed. Use of these animal models can enable planning of adjuvant treatment, potentially assisting in pre-operative and post-operative decision making. Discovery of novel biomarkers will allow, in combination with WHO grading, more precise meningioma grading, including meningioma identification, subtype determination, and prediction of metastasis, recurrence, and response to therapy. Moreover, these biomarkers may be exploited in the development of personalized targeted therapies that can distinguish between the 15 diverse meningioma subtypes.

Detection of diagnostic and prognostic methylation-based signatures in liquid biopsy specimens from patients with meningiomas

Recurrence of meningiomas is unpredictable by current invasive methods based on surgically removed specimens. Identification of patients likely to recur using noninvasive approaches could inform treatment strategy, whether intervention or monitoring. In this study, we analyze the DNA methylation levels in blood (serum and plasma) and tissue samples from 155 meningioma patients, compared to other central nervous system tumor and non-tumor entities. We discover DNA methylation markers unique to meningiomas and use artificial intelligence to create accurate and universal models for identifying and predicting meningioma recurrence, using either blood or tissue samples. Here we show that liquid biopsy is a potential noninvasive and reliable tool for diagnosing and predicting outcomes in meningioma patients. This approach can improve personalized management strategies for these patients.

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.

Advances in Central Nervous System Tumor Classification

Historically, the classification of tumors of the central nervous system (CNS) relies on the histologic appearance of cells under a microscope; however, the molecular era of medicine has resulted in new diagnostic paradigms anchored in the intrinsic biology of disease. The 2021 World Health Organization (WHO) reformulated the classification of CNS tumors to incorporate molecular parameters, in addition to histology, to define many tumor types. A contemporary classification system with integrated molecular features aims to provide an unbiased tool to define tumor subtype, the risk of tumor progression, and even the response to certain therapeutic agents. Meningiomas are heterogeneous tumors as depicted by the current 15 distinct variants defined by histology in the 2021 WHO classification, which also incorporated the first moelcular critiera for meningioma grading: homozygous loss of CDKN2A/B and TERT promoter mutation as criteria for a WHO grade 3 meningioma. The proper classification and clinical management of meningioma patients requires a multidisciplinary approach, which in addition to the information on microscopic (histology) and macroscopic (Simpson grade and imaging), should also include molecular alterations. In this chapter, we present the most up-to-date knowledge in CNS tumor classification, particularly in meningioma, in the molecular era and how it could affect their future classification and clinical management of patients with these diseases.

Dural metastasis from prostate carcinoma mimicking tuberculum sellae meningioma: A case report

Background:

Prostate carcinoma rarely metastasizes to the central nervous system. However, when it does, a dural lesion is a common and possible misdiagnosis of meningioma. Here, we describe a case of a 77-year-old man with dural metastasis from prostate carcinoma of the tuberculum sellae.

Case Description:

The patient was diagnosed with prostate carcinoma 7 years previously and was well-controlled by hormone therapy. He was incidentally found to have a suprasellar tumor and underwent endoscopic endonasal transsphenoidal surgery because of rapid tumor growth and worsening visual impairment. Since his serum prostate-specific antigen (PSA) level was within the normal range, malignant meningioma was suspected based on the magnetic resonance imaging (MRI) and the course. However, the pathological findings revealed dural metastasis from prostate carcinoma. He received radiation therapy, and the tumor disappeared on MRI. His visual impairment improved without recurrence. This case report highlights that dural metastasis of the tuberculum sellae arose despite the patient’s PSA level being within the normal range, and a single metastasis to the dura was found.

Conclusion:

In patients with a history of prostate carcinoma or older men, careful follow-up considering the possibility of metastasis is required when a dural lesion is found.

Rate of incidental central nervous system meningioma detected in patients undergoing 18F-fluciclovine PET/CT imaging for evaluation of prostate cancer

OBJECTIVE

To evaluate the rate of incidental detection of central nervous system (CNS) meningioma in patients undergoing 18F-fluciclovine PET/computed tomography (CT) imaging for the evaluation of prostate cancer.

METHODS

The reports of 850 18F-fluciclovine PET/CT scans in 566 patients with pathologically proven prostate cancer performed from April 2017 to July 2019, were retrospectively reviewed for the presence of CNS meningioma.

RESULTS

A total of 14 patients (2.8%) (age range: 54-82 years old) had abnormal focal intracranial 18F-fluciclovine uptake, all extra-axial in location (SUVmax range: 3.2-19.3). Two cases out of 14 (0.35%) were diagnosed as metastatic lesions. Twelve out of the 14 patients, had 18F-fluciclovine PET/CT imaging findings suspicious for CNS meningioma, 2 of them received another diagnosis on further imaging, and only 10 cases (2%) had the diagnosis of meningioma according to follow-up MRI and 18F-fluciclovine PET/CT.

CONCLUSION

Focal 18F-fluciclovine avid intracranial lesions incidentally detected in patients undergoing PET/CT imaging for prostate cancer are most often CNS meningiomas.

A double mutation of BRAF L597Q and V600E in situ and solitary brain metastasis of occult papillary thyroid carcinoma: A case report

RATIONALE

The rare BRAF L597Q (c.T1790A) point mutation has been previously reported in childhood acute lymphoblastic leukemia. We present the first rare case of occult papillary thyroid carcinoma with BRAF L597Q mutation in a Tibetan patient.

PATIENT CONCERNS

A 57-year-old male patient presented with a protruding mass on the left forehead for 2 years and numbness in the right limb for 3 weeks.

DIAGNOSES

The patient had a double mutation of BRAF L597Q and V600E in 2 separate lesions at thyroid and brain, the immunohistochemical staining showed that the cytokeratin (CK), thyroglobulin (Tg) and thyroid transforming factor-1 (TTF-1) were immunoreactive. All the findings supported the diagnosis of solitary brain metastasis of occult papillary thyroid carcinoma.

INTERVENTIONS

The patient underwent left frontal lobe metastasis (thyroid cancer) resection that involved craniectomy and artificial skull repair.

OUTCOMES

During the 24-month follow-up, no postoperative complications or recurrence and metastasis were found.

LESSONS

This is the first case of solitary brain metastasis of occult papillary thyroid carcinoma with double mutation of BRAF L597Q and V600E in 2 separate lesions reported in the literature. Our study extends the disease spectrum of occult papillary thyroid carcinoma and suggests that the BRAF L597Q mutation might play a specific role in inducing the solitary brain metastasis of occult papillary thyroid carcinoma in a Chinese Tibetan patient, but the detailed molecular mechanism remains to be confirmed by a large number of functional experiments and clinical research.

Radio-pathological review of a metastatic renal cell carcinoma within a meningioma: A case report of collision tumor

We report a case of a collision tumor, a meningioma complicated with metastasis from a primary renal cell carcinoma. A 75-year-old man, with known history of renal cell carcinoma, and 10-year history of stable meningioma developed neurological symptoms. Computed tomography and magnetic resonance imaging revealed left frontal intracranial extra-axial mass with imaging criteria suspicious for an atypical meningioma or hemangiopericytoma. Given the history of a known primary, the possibility of brain metastasis was included. Pathology confirmed the presence of metastatic renal cell carcinoma nidus with a surrounding meningioma. Tumor-to-tumor metastasis or collision tumor is a very rare phenomenon. Atypical radiologic findings with positive history of a primary extracranial tumor should raise the suspicion of potential metastases.

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.

Thyroid Carcinoma Presenting as a Dural and Calvarial Metastasis Mimicking a Lipoma With Difficult Diagnosis of the Primary Lesion

Calvarial and dural metastases of papillary thyroid carcinomas (PTC) are rarely reported in the medical literature. Most frequent calvarial metastases are seen to originate from lung, breast, and prostate cancers. Thyroid cancer metastases are generally well vascularized and cause destruction in the bone tissues. First choice of treatment in distant metastases of PTC is surgery and radioactive iodine treatment for the primary cause. Postsurgical radiotherapy is used in accepted and suitable patients.

"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.

Skeletal Metastases and Benign Mimics on NaF PET/CT: A Pictorial Review

OBJECTIVE

The aim of this article is to present examples in which sodium fluoride labelled with ¹⁸F (NaF) bone PET/CT would be a useful adjunct to guide complex clinical decisions about the staging, restaging, and treatment approach for patients with skeletal metastases and benign causes of NaF activity that can be mistaken for bone metastases. We present a pictorial review of selected cases of this cohort of patients.

CONCLUSION

NaF PET/CT hybrid fusion imaging is extremely useful in identifying potential causes of pain in patients with malignancies that have an affinity for skeletal metastases. This technique can help detect bone metastases, in problem solving, and to direct appropriate management.

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.

Simultaneous meningioma and brain metastasis from renal cell carcinoma - a rare presentation. Case report

CONTEXT:

Brain metastases are the most common tumors of the central nervous system. Because of their high frequency, they may be associated with rare situations. Among these are tumor-to-tumor metastasis and an even a rarer situation called simultaneous brain tumors, which are more related to primary tumors of the reproductive and endocrine systems.

CASE REPORT:

A 56-year-old male patient with a history of renal cell carcinoma (which had previously been resected) presented with a ventricular lesion (suggestive of metastatic origin) and simultaneous olfactory groove lesion (probably a meningioma). First, only the ventricular lesion was dealt with, but after a year, the meningothelial lesion increased and an occipital lesion appeared. Therefore, both of these were resected in a single operation. All the procedures were performed by the same neurosurgeon. The patient evolved without neurological deficits during the postoperative period. After these two interventions, the patient remained well and was referred for adjuvant treatment.

CONCLUSIONS:

This study provides the first description of an association between these two tumors. Brain metastases may be associated with several lesions, and rare presentations such as simultaneity with meningioma should alert neurosurgeons to provide the best oncological treatment.

Headache Caused by Brain Metastases of Castration-resistant Prostate Cancer during Cabazitaxel Therapy

We describe the case of a 55-year-old man who underwent four cycles of cabazitaxel therapy for castration-resistant prostate cancer (CRPC). After the fourth cycle of cabazitaxel, the patient experienced severe headaches. Brain gadolinium (Gd) contrast-enhanced magnetic resonance imaging (MRI) revealed multiple brain metastases. A few days later, the patient suffered impaired consciousness that progressed rapidly. The patient was treated for the symptoms of increased intracranial pressure and underwent whole-brain radiation. One month later, the patient's consciousness level and headache had improved. Although brain metastases of prostate cancer are rare, the possibility of brain metastases should be considered for prostate cancer patients, especially when a CRPC patient complains of headache. Additionally, even if major conditions such as cerebral hemorrhage are excluded by the use of non-contrast-enhanced computed tomography, brain Gd contrast-enhanced MRI should be performed in consideration of the possibility of brain metastases of prostate cancer.

Facial Paralysis and Hearing Loss: A Rare Manifestation of Prostate Cancer Metastases

Dural prostate metastases (DPM) are a rare manifestation of metastatic prostate cancer seen in approximately one to six percent of cases. Presenting symptoms may include signs of elevated intracranial pressure, headache, altered mental status, or cranial nerve palsies. Hearing loss, sensory changes, dysarthria, and dysphagia are rare symptoms in DPM that were present in our patient. We present a case of a 58-year-old male with a known diagnosis of adenocarcinoma of the prostate presenting with symptoms of acute exacerbation of chronic obstructive pulmonary disease (COPD), sub-acute right-sided hearing loss, and right-sided facial paralysis. Over the course of hospitalization, his neurological symptoms worsened and he developed dysarthria, dysphagia, facial numbness, and worsening back pain. He also appeared more withdrawn and lethargic. The symptoms prompted a neurological evaluation and a magnetic resonance imaging (MRI) revealed multiple areas of bone marrow signal abnormality compatible with osseous metastatic disease. There was extensive smooth dural thickening as well as focal nodular thickening, both consistent with dural metastases. The patient was treated with corticosteroids and external beam radiation therapy (EBRT) with improvement in his back pain and facial paralysis. He died two weeks after completing EBRT. Although rare, DPM should be suspected in males over 50 years of age presenting with neurological symptoms. An MRI with gadolinium is most helpful in delineating the presence and extent of dural and calvarial involvement. Corticosteroids and EBRT have been shown to improve neurological function in up to 67% of patients. However, median survival post-radiation remains approximately three months.

A 'silent' skull metastatic follicular thyroid carcinoma mimicking as a benign scalp tumor in a pregnant woman

Thyroid cancer with cranial metastasis in a pregnant woman is very rare. In the literature, most cases are diagnosed early from neurogenic signs or symptomatic thyroid gland. Pregnancy also contributes to a hesitation toward early surgical and medical treatments. We reported a scalp tumor in a physically healthy 37-year-old pregnant female with a follicular thyroid carcinoma (FTC) with lung, bone and cranial metastasis in initial presentation. Silent neurogenic and physical examinations make an early diagnosis very challenging. Resection of scalp and intracranial tumor, a thyroidectomy, post-operative radioactive iodine therapy and tyrosine kinase inhibitors were employed as treatment. The scalp tumor was confirmed as a metastatic follicular thyroid carcinoma via positive immunoreactivity for thyroglobulin and thyroid transcription factor 1 in tumor cells. Blood examination revealed an elevated thyroglobulin level (>5335 ng/mL). The patient was discharged without any neurological deficit. An asymptomatic scalp tumor in a pregnant woman with a normal thyroid disease history needs differential diagnosis from intracranial origin. Rapid progression and an elevated thyroglobulin level are the indicators that further image study is needed. Aggressive surgical excision of resectable thyroid gland and metastatic tumor are essential for a longer survival rate. There is nothing to indicate that a post-partum operation will worsen prognosis.

Suspected tumor-to-meningioma metastasis: A case report

Tumor-to-meningioma metastasis (TMM) is a fairly uncommon phenomenon. Only 7 cases of prostate cancer with TMM have previously been described in the literature. The present study aimed to report a case of prostate cancer TMM, and to discuss the relevant clinical and neuroimaging aspects of this condition. A 68-year-old patient presented with headaches, poor visual acuity in the left eye and ipsilateral eyelid droop 3 years after a Simpson II resection of a left sphenoid wing meningioma. Computed tomography revealed a hyperdense area suggestive of a recurrent left sphenoid wing meningioma. During microsurgical resection of tumor, the tumor presented a fibrous aspect and bled profusely. In the histological examination, a metastatic adenocarcinoma was identified inside the transitional meningioma. The immunohistochemical exam favored a prostatic primary site. The patient died two months later of septic shock from pneumonia. This is a rare metastatic presentation. The pre-operative diagnosis of TMM remains challenging in the majority of cases.

Intraparenchymal hemorrhage from dural metastasis of breast cancer mimicking meningioma

Intraparenchymal hemorrhage from dural metastasis of breast cancer is rare. A 54-year-old woman without a significant medical history showed altered consciousness and left hemiparesis. Radiological examination revealed an extra-axial mass in the right middle fossa with intraparenchymal hemorrhage and another mass invading the skull in the right parietal region. The pre-operative diagnosis was a sphenoid ridge meningioma presenting with intraparenchymal hemorrhage and another meningioma in the convexity. The tumors and hematoma were removed. Pathological findings of the tumors were compatible with adenocarcinoma. Systemic examination revealed breast cancer with metastasis to the spine. Although the radiological findings were similar to those of meningioma, a differential diagnosis of metastatic brain tumor with intraparenchymal hemorrhage should be taken into consideration.

Calvarium and dura mater as delayed sites of distant metastasis from papillary thyroid carcinoma

Background

Skull calvarium and dura mater are rare sites of distant metastasis, and mostly have been reported in lung, breast, and prostate malignancies. However, the calvarial and dural metastases from papillary thyroid cancer (PTC) are rare entities and pose diagnostic and therapeutic challenges. To date, only seven cases of calvarial metastasis with intracranial extension from PTC have been reported in literature. However, true dural metastasis from PTC has not yet been reported.

Case presentation

A 65-year-old Saudi woman presented with 6 months history of painful posterior scalp lump, 7 years after initial diagnosis of PTC. Computed tomography and magnetic resonance imaging showed occipitoparietal calvarial lesion with massive intracranial extension. Another para-sagittal lesion was found at the top of corpus callosum mimicking a meningioma. Histopathology of para-sagittal lesion and the biopsy of calvarial mass confirmed the diagnosis of metastatic PTC. After surgical resection, residual tumors were treated with postoperative intensity-modulated radiation therapy. At 13 months of follow-up, patient was alive and without any signs of recurrence.

Conclusion

Calvarial and dural metastases from PTC are extremely rare clinical entities. Surgical resection followed by postoperative radiotherapy is the treatment of choice. However, for such cases, multidisciplinary approach can prolong the treatment outcome and survival.

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.

Dural metastasis of nasopharyngeal carcinoma: rare, but worth considering

Metastasis of nasopharyngeal carcinoma (NPC) to the dura, an extremely rare condition, can be symptomatically silent and mistaken for a benign entity radiographically. Missed diagnosis can lead to serious consequences or prove immediately fatal. We report a woman with dural metastasis of NPC that mimicked a meningioma on radiography. Craniectomy with tumour resection was performed due to rapid progression from the onset of symptoms to disability. The patient was still alive two years after surgery. This case emphasises the need to keep in mind the possibility of dural metastasis of NPC in patients with abnormal imaging features. This would not only avoid wrong and optimistic diagnosis, but also allow for appropriate treatment in a timely manner. To our knowledge, this is the first report of metastasis of NPC to the dura. We provide detailed information on the neoplastic lesion, which masqueraded as a benign entity and caused potentially fatal consequences.

Brain tumor classification using the diffusion tensor image segmentation (D-SEG) technique

Background

There is an increasing demand for noninvasive brain tumor biomarkers to guide surgery and subsequent oncotherapy. We present a novel whole-brain diffusion tensor imaging (DTI) segmentation (D-SEG) to delineate tumor volumes of interest (VOIs) for subsequent classification of tumor type. D-SEG uses isotropic (p) and anisotropic (q) components of the diffusion tensor to segment regions with similar diffusion characteristics.

Methods

DTI scans were acquired from 95 patients with low- and high-grade glioma, metastases, and meningioma and from 29 healthy subjects. D-SEG uses k-means clustering of the 2D (p,q) space to generate segments with different isotropic and anisotropic diffusion characteristics.

Results

Our results are visualized using a novel RGB color scheme incorporating p, q and T2-weighted information within each segment. The volumetric contribution of each segment to gray matter, white matter, and cerebrospinal fluid spaces was used to generate healthy tissue D-SEG spectra. Tumor VOIs were extracted using a semiautomated flood-filling technique and D-SEG spectra were computed within the VOI. Classification of tumor type using D-SEG spectra was performed using support vector machines. D-SEG was computationally fast and stable and delineated regions of healthy tissue from tumor and edema. D-SEG spectra were consistent for each tumor type, with constituent diffusion characteristics potentially reflecting regional differences in tissue microstructure. Support vector machines classified tumor type with an overall accuracy of 94.7%, providing better classification than previously reported.

Conclusions

D-SEG presents a user-friendly, semiautomated biomarker that may provide a valuable adjunct in noninvasive brain tumor diagnosis and treatment planning.

Metastatic renal cell carcinoma, with a radiographically occult primary tumor, presenting in the operative site of a thoracic meningioma: long-term follow-up: Case report

Lesions metastatic to the site of a meningioma resection from a different primary tumor are rare. Metastasis of a tumor without a known primary tumor is also rare. Metastasis of a renal cell carcinoma, without an identifiable primary tumor, to the bed of a meningioma resection has not been previously reported. The authors describe the case of a 54-year-old man who presented with decreased sensory and motor function in the lower extremities. He underwent T3-5 laminectomies and gross-total removal of an intradural, extramedullary meningioma. The postoperative course was uneventful, and the patient regained full neurological function. After a 3-year period, he developed progressive upper thoracic pain and lower-extremity paresthesias. Imaging studies showed an epidural mass at the T2-4 levels and what appeared to be blastic involvement of the T2-4 vertebrae. A metastatic workup was negative. Emergency revision laminectomies yielded a fibrous, nonvascular mass. Neuropathology was consistent with metastatic renal cell carcinoma. After 6 months, the patient's symptoms of pain and paresthesias recurred. Repeat excision, with decompression of the spinal cord, revealed tumor cells morphologically and immunophenotypically similar to those obtained from the prior surgery. Cytogenetic analysis confirmed the presence of metastatic renal cell carcinoma. A novel case of an epidural metastatic renal cell carcinoma, of unknown primary origin, in the same operative bed of a previously resected intradural, extramedullary meningioma of the thoracic spine is reported.

Rare presentation of metastatic prostate adenocarcinoma as a meningioma mimic

Background Dural lesions in the anterior skull base may occur secondary to benign or malignant pathology that may be difficult to differentiate on imaging. Detailed clinical evaluation in many cases will narrow the differential diagnosis. In spite of using all the available information, in certain cases the underlying etiology of a lesion remains unclear.

Participant We report a rare case of metastatic prostate adenocarcinoma to a meningioma in a 67-year-old-man who presented with progressive confusion and mental status alterations with no prior history of malignancy. Neuroimaging revealed a large anterior skull base lesion.

Results The lesion was surgically resected, and histopathology revealed a collision tumor, in which prostate adenocarcinoma was found admixed with a World Health Organization grade I meningioma.

Conclusion Anterior dural skull base lesions can be either benign or malignant. Although infrequently reported, a benign-appearing dural-based lesion may be a manifestation of an underlying malignancy, and a thorough clinical, radiologic, and pathologic examination may be necessary, especially in the elderly.

Metastatic prostate mass to the intradural foramen magnum region: a case report

Intradural metastatic tumors of the foramen magnum region are extremely rare tumors. We report a 73-year-old patient that presented with right hemiparesis and a recent history of prostate biopsy for an enlarged prostate. Imaging revealed an anterolateral intradural foramen magnum mass with compression of the medulla. A right far lateral approach with condyle preservation was used to resect the mass. Pathological examination revealed the tumor as a metastatic prostate mass. The patient had a significant recovery of motor function and was given adjuvant external beam radiation. At the time of last follow-up, the patient had good clinical relief from the preoperative symptoms. To our knowledge, this is the first reported case of an intradural foramen magnum prostate tumor metastasis. We report on multimodal management of this rare, yet morbid presentation of a common tumor.

A case of metastatic adenocarcinoma of the prostate arising in a meningioma

We present the case of a 70-year-old man who had a prostate adenocarcinoma that metastatized to a previously unknown cranial meningioma. Central nervous system (CNS) metastases are very uncommon in patients with prostate cancer, and metastases to pre-existing primary CNS tumours are even more uncommon. Rare events like this can cause diagnostic uncertainty, as shown by this case. This case is a reminder for clinicians to consider prostate metastases in patients with known prostate carcinoma and focal neurological symptoms.

Thyroid carcinoma presenting as a dural metastasis mimicking a meningioma: A case report

Context:

Follicular thyroid cancer rarely manifests itself as a distant metastatic lesion.

Case Report:

We report a case of a 41-year old man presented with a solid mass located in the left temporo-occipital region. The 3D computed tomography showed a large solid mass with high vascularity, skull erosion and supra-infratentorial epidural mass effect. After magnetic resonance imaging (MRI) a suspect diagnosis of meningioma was made. The patient underwent surgery where a soft mass with transverse sinus invasion was encountered; the tumour was successfully resected employing microsurgical techniques. Histological examination revealed a thyroid follicular neoplasm with positive staining for follicular carcinoma in immunohistochemical analysis. Postoperatively levels of thyroid hormones were normal. Treatment was planned for the thyroid gland, patient receiving 6 courses of chemotherapy including paclitaxel.

Conclusions:

The present case emphasizes that although they are uncommon, dural metastasis can be mistaken for meningiomas. The definitive diagnosis of a meningioma should be established only after the histopathological analysis. Thyroid follicular carcinoma should be included in the differential diagnosis in cases of extrinsic tumoral lesions.

[A case of mantle cell lymphoma with meningioma]

Mantle cell lymphoma (MCL) is an uncommon type of gastrointestinal lymphoma. MCL is a distinct subtype of B-cell non-Hodgkin lymphomas. The major subtype of MCL is characterized by the presence of multiple lymphomatous polyposis (MLP), in which multiple polyps are observed along the gastrointestinal tract. The malignant cells express pan B-cell marker and the T-cell marker cluster of differentiation 5. The chromosomal translocation t(11;14)(q13;q32) that causes cyclin D1 overexpression is commonly observed on the cytogenetic analysis of MCL. Survival improvement has recently been achieved for patient with MCL by the successful introduction of monoclonal antibodies and dose-intensified approaches for treatment, including autologous stem cell transplantation strategies. Some reports suggest that there is an increased incidence of second malignancies in patients with MCL or lymphoma. We report a case of MCL involving the colon; the patient was a 60-year-old man who complained of low abdominal discomfort during defecation. During the workup, a meningioma was unexpectedly discovered. On analysis, the tumor was found to be a t(11;14)-negative and non-MLP-type MCL.

Skull metastasis in papillary carcinoma of thyroid: A case report

Papillary thyroid carcinoma with metastasis to the skull is extremely rare. We report a case of unsuspected papillary thyroid carcinoma with skull metastasis. A 48-year-old female patient presenting with painless, pulsatile, progressively increasing swelling in the occipitoparietal region of the scalp approached for an X-ray of the skull. Ultrasound of palpable swelling in the neck revealed a heteroechoic lesion with increased vascularity. Foci of calcification were seen involving both lobes of the thyroid. Ultrasound of scalp showed a destructive mass in the skull with increased vascularity. Biopsy of thyroid lesions revealed branching papillae having a dense fibrovascular core covered by cuboidal epithelial cells with nuclei having a clear ground glass appearance. This case illustrates how isolated extensive skull metastasis can be found in papillary carcinoma patients without causing significant morbidity. Therefore, in the clinical course of thyroid papillary carcinoma, skull metastasis should be considered, and the patients should be meticulously investigated and followed up.

Quantitative short echo time 1H MRSI of the peripheral edematous region of human brain tumors in the differentiation between glioblastoma, metastasis, and meningioma

PURPOSE

To assess metabolite levels in peritumoral edematous (PO) and surrounding apparently normal (SAN) brain regions of glioblastoma, metastasis, and meningioma in humans with (1)H-MRSI to find biomarkers that can discriminate between tumors and characterize infiltrative tumor growth.

MATERIALS AND METHODS

Magnetic resonance (MR) spectra (semi-LASER MRSI, 30 msec echo time, 3T) were selected from regions of interest (ROIs) under MRI guidance, and after quality control of MR spectra. Statistical testing between patient groups was performed for mean metabolite ratios of an entire ROI and for the highest value within that ROI.

RESULTS

The highest ratios of the level of choline compounds and the sum of myo-inositol and glycine over N-acetylaspartate and creatine compounds were significantly increased in PO regions of glioblastoma versus that of metastasis and meningioma. In the SAN region of glioblastoma some of these ratios were increased. Differences were less prominent for metabolite levels averaged over entire ROIs.

CONCLUSION

Specific metabolite ratios in PO and SAN regions can be used to discriminate glioblastoma from metastasis and meningioma. An analysis of these ratios averaged over entire ROIs and those with most abnormal values indicates that infiltrative tumor growth in glioblastoma is inhomogeneous and extends into the SAN region.

Intracranial dural metastatic prostate cancer can mimic meningioma: a report of two cases

Cerebral metastases from any malignancy, including prostate carcinoma, may present as a meningeal mass, and differentiating the lesion from a meningioma can be challenging. We report the clinical and neuroimaging features of two patients with dural metastases from prostate carcinoma and discuss differentiation of metastatic lesions from meningioma. In both patients, it appeared that the prostate carcinoma had been successfully treated, and neither patient was found to have any other metastases at the time of diagnosis of the dural lesions.

Contribution of perfusion-weighted magnetic resonance imaging in the differentiation of meningiomas and other extra-axial tumors: case reports and literature review

We present six cases of extra-axial lesions: three meningiomas [including one intraventricular and one cerebellopontine angle (CPA) meningioma], one dural metastasis, one CPA schwannoma and one choroid plexus papilloma which were chosen from a larger cohort of extra-axial tumors evaluated in our institution. Apart from conventional MR examinations, all the patients also underwent perfusion-weighted imaging (PWI) using dynamic susceptibility contrast method on a 1.5 T MR unit (contrast: 0.3 mmol/kg, rate 5 ml/s). Though the presented tumors showed very similar appearance on conventional MR images, they differed significantly in perfusion examinations. The article draws special attention to the usefulness of PWI in the differentiation of various extra-axial tumors and its contribution in reaching final correct diagnoses. Finding a dural lesion with low perfusion parameters strongly argues against the diagnosis of meningioma and should raise a suspicion of a dural metastasis. In cases of CPA tumors, a lesion with low relative cerebral blood volume values should be suspected to be schwannoma, allowing exclusion of meningioma to be made. In intraventricular tumors arising from choroid plexus, low perfusion parameters can exclude a diagnosis of meningioma. In our opinion, PWI as an easy and quick to perform functional technique should be incorporated into the MR protocol of all intracranial tumors including extra-axial neoplasms.

Quantitative combination of volumetric MR imaging and MR spectroscopy data for the discrimination of meningiomas from metastatic brain tumors by means of pattern recognition

The analysis of information derived from magnetic resonance imaging (MRI) and spectroscopy (MRS) has been identified as an important indicator for discriminating among different brain pathologies. The purpose of this study was to investigate the efficiency of the combination of textural MRI features and MRS metabolite ratios by means of a pattern recognition system in the task of discriminating between meningiomas and metastatic brain tumors. The data set consisted of 40 brain MR image series and their corresponding spectral data obtained from patients with verified tumors. The pattern recognition system was designed employing the support vector machines classifier with radial basis function kernel; the system was evaluated using an external cross validation process to render results indicative of the generalization performance to "unknown" cases. The combination of MR textural and spectroscopic features resulted in 92.15% overall accuracy in discriminating meningiomas from metastatic brain tumors. The fusion of the information derived from MRI and MRS data might be helpful in providing clinicians a useful second opinion tool for accurate characterization of brain tumors.

Presentation, treatment, and outcomes of dural metastases in men with metastatic castrate-resistant prostate cancer: a case series

PURPOSE

Men with metastatic castrate-resistant prostate cancer (mCRPC) have shown increased survival since the introduction of docetaxel-based chemotherapy in 2004. While bone metastases are common in prostate cancer, cranial dural metastases (DM) are not. We hypothesize that longer survival in patients with mCRPC may increase the incidence of uncommon metastatic sites, including the cranial dura. We describe 10 cases of DM in men with mCRPC and review the relevant literature.

MATERIALS AND METHODS

We conducted a retrospective chart review of 10 subjects with mCRPC, diagnosed ante-mortem with DM at our institution between August 1, 2003 and June 1, 2008. Variables analyzed included prognostic factors at prostate cancer diagnosis, number of therapies prior to DM, treatments administered for DM with response achieved, and survival following diagnosis of DM.

RESULTS

Median age at prostate cancer diagnosis was 59 years (range, 52-80), with a median Gleason's score of 9 (range, 8-10) and prostate-specific antigen (PSA) of 37 ng/dL (range, 4.9-118). Fifty percent had metastatic disease at initial diagnosis. A median of 5 therapies (range, 1-13) were administered prior to diagnosis of DM, including a median of 1 course of chemotherapy (range, 1-3). Cranial neuropathies were the most common presenting symptoms of DM, and 8 of 10 patients received treatment for their DM, most often radiotherapy. Median survival for this group was 6.17 months (range, < 1-15).

CONCLUSIONS

Treatment advances in mCRPC may lead to an increased incidence of previously rare metastatic sites. CNS symptoms in men with mCRPC should prompt evaluation for DM.

Neurosurgical treatment of breast cancer metastases to the neurocranium

Breast cancer metastases to the neurocranium might involve the bone, the dura, or the brain parenchyma. The latter location is the far most common. The annual incidence of brain metastases in patients with breast cancer is in the range of 4–11 per 100.000 persons per year. Symptoms and findings mainly result from the location of the lesion. The diagnostic method of choice is magnetic resonance imaging before and after administration of contrast material. Breast cancer brain metastases present as solid, cystic, or partially cystic lesions with marked contrast enhancement and perilesional edema. The therapeutic option of choice is microsurgical resection whenever possible. Adjuvant treatment includes radiotherapy, radiosurgery, and/or chemotherapy.