Clear Cell Meningioma: A Clinicopathologic Study of 18 Tumors and Examination of the Use of CD10, CA9, and RCC Antibodies to Distinguish Between Clear Cell Meningioma and Metastatic Clear Cell Renal Cell Carcinoma

Pituitary Adenoma Coexistent with Sellar Clear Cell Meningioma Unattached to the Dura: Case Report and Treatment Considerations

Collision tumors involving the sella are rare. Intrasellar collision tumors are most commonly composed of a combination of pituitary adenomas and pituitary neuroendocrine tumors; however, collision tumors consisting of a pituitary adenoma and intrasellar meningioma are exceedingly rare. The authors present the case of a 47-year-old man who presented with progressive right eye vision loss. Magnetic resonance imaging showed a large, heterogeneously enhancing sellar mass with suprasellar extension. Using a transcranial approach with a right subfrontal craniotomy, near-total resection of the mass was achieved. Histologic analysis confirmed a diagnosis of a gonadotroph adenoma with concomitant clear cell meningioma (CCM). This patient was discharged with improvement in visual acuity and no signs of diabetes insipidus. Given the indistinguishable radiographic characteristics of pituitary adenoma and CCM, a preoperative diagnosis of a collision tumor was difficult. This case was uniquely challenging since the CCM component lacked the classic dural attachment that is associated with meningiomas on neuroimaging. CCMs are classified as central nervous system (CNS) World Health Organization (WHO) grade 2 tumors and tend to behave more aggressively, therefore warranting close surveillance for signs of tumor recurrence. This is the first case to report a collision tumor consisting of pituitary adenoma and CCM.

Pulmonary primary meningioma: A report of two cases and review of the literature

Introduction

Primary pulmonary meningioma (PPM) is rare, mostly asymptomatic, and difficult to recognize preoperatively. In this report, we describe two new cases of PPM and provide an updated review of the literature to enhance our understanding of PPM.

Case presentation

The first patient was a 53-year-old woman with an asymptomatic solitary pulmonary nodule in the right lower lobe on chest computed tomography (CT). Wedge resection of the right lung was performed and histological features of benign PPM were pathologically confirmed, which was further supported by immunohistochemistry. The second patient was a 63-year-old man who had a left pulmonary nodule during routine physical examination. CT revealed a solid nodule in the outer basal segment of the left lower lobe. The patient underwent a wedge resection of the left lower lobe and mediastinal lymph node dissection. Postoperative pathology confirmed the presence of two tumors: one adenocarcinoma and one PPM. Both cases were confirmed to be benign PPM (grade I) by pathological examination, with histological subtypes of fibrous and psammomatous.

Conclusions

Radiological imaging is crucial for the early detection of PPM, while pathological examination is necessary to confirm the diagnosis. Surgical treatment is recommended, and intraoperative frozen sections are essential for determining the extent of the operation.

Meningioma: A Pathology Perspective

Meningiomas are dural-based neoplasms that account for ∼37% of all intracranial tumors in the adult population. They can occur anywhere within the central nervous system and have a predilection for females. The World Health Organization classifies meningiomas into 3 grades based on increased risk of recurrence and associated mortality in grade III tumors. Although most tumors are categorized as low-grade, up to ∼15%-20% demonstrate more aggressive behavior. With the long-recognized association with neurofibromatosis type 2 gene mutation, putative driver mutations can be attributed to ∼80% of tumors. Several germline mutations have also been identified in some cases of familial meningiomatosis such as SMARCE1, SUFU, PTEN, and BAP1. Finally, in addition to genetic data, epigenetic alterations, specifically deoxyribonucleic acid methylation, are being increasingly recognized for their prognostic value, potentially adding objectivity to a currently subjective grading scheme.

The Expression of Carbonic Anhydrases II, IX and XII in Brain Tumors

Carbonic anhydrases (CAs) are zinc-containing metalloenzymes that participate in the regulation of pH homeostasis in addition to many other important physiological functions. Importantly, CAs have been associated with neoplastic processes and cancer. Brain tumors represent a heterogeneous group of diseases with a frequently dismal prognosis, and new treatment options are urgently needed. In this review article, we summarize the previously published literature about CAs in brain tumors, especially on CA II and hypoxia-inducible CA IX and CA XII. We review here their role in tumorigenesis and potential value in predicting prognosis of brain tumors, including astrocytomas, oligodendrogliomas, ependymomas, medulloblastomas, meningiomas, and craniopharyngiomas. We also introduce both already completed and ongoing studies focusing on CA inhibition as a potential anti-cancer strategy.

Clear Cell Meningioma: A Clinicopathologic Study of a Rare Meningioma Subtype in 35 Patients

OBJECTIVE

Clear cell meningioma (CCM) is a rare histologic variant, accounting for only 0.2%-0.8% of all meningiomas. Given their relative infrequency, few cases have been reported. We have presented one of the largest series of patients with intracranial CCM and reported the treatments and outcomes of these patients.

METHODS

Patients with histologically proven CCM from 2003 to 2018 were identified for inclusion in the present study. Relevant clinical and radiographic data were obtained via retrospective review and analyzed. Kaplan-Meier and Cox proportional hazards analyses were used to compare overall and progression-free survival.

RESULTS

A total of 35 patients had undergone surgical resection for CCM, including 18 women and 17 men, with a mean age of 59.3 years. Gross total resection was achieved in 22 patients (62.9%), and 11 patients (31.4%) had received adjuvant postoperative radiotherapy. Tumors recurred in 17 patients (48.6%), with a mean time to recurrence of 31.3 months. The mean postoperative follow-up was 66.3 months. On multivariable analysis, adjuvant radiotherapy and gross total tumor resection were both independently associated with prolonged progression-free survival (P < 0.033), although not with overall survival (P >0.274).

CONCLUSIONS

The data from the present series of 35 patients with CCM have shown distinct contrasts to previous series, with an older mean age and a nearly 1:1 male/female ratio. Although gross total resection and adjuvant postoperative radiotherapy were both independently associated with longer progression-free survival for patients with CCM, tumor recurrence has remained a challenge in the treatment of these patients.

Advances in Diagnostic Immunohistochemistry for Primary Tumors of the Central Nervous System

As genomic characterization becomes increasingly necessary for accurate diagnosis of tumors of the central nervous system, identification of rapidly assessible biomarkers is equally important to avoid excessive cost and delay in initiation of therapy. This article reviews novel immunohistochemical markers that may be used to determine mutation status, activation of signaling pathways, druggable targets, and cell lineage in many diverse tumor types. In particular, recently added entities to the 2016 WHO classification of central nervous system tumors will be addressed, including IDH-mutant gliomas, diffuse midline glioma, epithelioid glioblastoma, angiocentric glioma, RELA-rearranged ependymoma, embryonal tumors (medulloblastoma, atypical teratoid/rhabdoid tumor, pineoblastoma, embryonal tumor with multilayered rosettes, and other genetically defined high-grade neuroepithelial tumors), and meningiomas associated with germline alterations.

Pediatric clear cell meningioma involving the middle cranial fossa in the context of NF2 and SMARCE1 mutations

Meningiomas are an uncommon entity in children and adolescents. <30 cases of pediatric clear cell meningioma (CCM), a World Health Organization (WHO) Grade II tumor, have been reported in the literature. These tumors are more likely to recur than the more common WHO Grade I meningiomas, especially with incomplete surgical resection. CCMs are most commonly found in the spine and posterior cranial fossa. Recently, SMARCE1 mutations have been linked to the development of CCM. To evaluate the progression of pediatric CCM in the context of emerging genetic knowledge, we reviewed all 45 cases of CCM at our institution for a 23 year period (1997-2019) to identify pediatric cases. Forty-four of the tumors arose in adults from age 34-81 years. The one pediatric case originally presented at age 4 years; the patient was found to have a CCM in the left cavernous sinus projecting into the posterior fossa, associated with a novel germline SMARCE1 mutation and somatic NF1 and DMD mutations. After two years, the patient had a recurrence of the tumor and underwent a second resection. This is the 5th reported case of CCM in the middle cranial fossa, and the only recurrent case, as well as the only reported case of recurrent pediatric CCM associated with a germline SMARCE1 mutation. Further study of the natural history of tumors associated with germline SMARCE1 loss could potentially inform prognosis.

Spinal Clear Cell Meningiomas: Clinical Features and Factors Predicting Recurrence

OBJECTIVE

As a World Health Organization grade II tumor of the nervous system, clear cell meningioma (CCM) is an uncommon histologic variant of meningioma. Spinal CCMs are even rarer, with <100 spinal CCMs reported in the English literature. We present this study to characterize clinical manifestations of spinal CCMs and determine the factors predicting recurrence.

METHODS

A literature search was performed for relevant case reports and series in PubMed and Embase until September 1, 2019. These articles were reviewed to identify clinical features, treatment modalities, and prognosis of patients with spinal CCMs.

RESULTS

Eighty-four spinal CCMs were analyzed. Of these patients, 36 (42.9%) were young (age ≤18 years), and the mean age at resection was 24 years. Fifty-three patients (63.1%) were female and 31 (36.9%) were male. Most of the tumors (56/84, 66.7%) were located in the lumbar region. In 31 patients (36.9%) >2 segments in the craniocaudal direction were involved (number of involved segments ≥3 levels). Gross tumor resection was performed in 77 patients (91.7%). Twenty patients (23.8%) showed radiographic evidence of recurrence during follow-up. Recurrence-free survival at 1, 5, and 10 years after resection of spinal CCM was 87%, 71%, and 47%, respectively. Multivariate analysis showed that age ≤18 years (hazard ratio [HR], 3.64; P = 0.024), subtotal resection (HR, 3.43; P = 0.031), and segments involving ≥3 levels (HR, 5.66; P = 0.002) were associated with increased recurrence.

CONCLUSIONS

Spinal CCMs have their own unique clinical features compared with conventional spinal meningiomas and intracranial CCMs. Spinal CCMs have a predilection to affect younger patients, are prone to appear in the lumbar region, and have a high recurrence rate. Age ≤18 years, subtotal resection, and involvement of long segments (≥3 levels) are positive predictors of recurrence.

Spinal Versus Intracranial Meningioma: Aberrant Expression of CD10 and Inhibin with Relation to Clinicopathological Features and Prognosis

CD10 and inhibin are used mainly in CNS pathology to distinguish hemangioblastoma from metastatic clear cell renal cell carcinoma. Some meningiomas can mimic both tumors and so we aimed at this study to investigate the expression of both markers in a large number of meningioma cases. One hundred thirty-four meningioma samples were collected, 14 of them were spinal and 120 were intracranial. Manual TMA blocks were constructed using modified mechanical pencil tip method and immunohistochemistry for CD10 and inhibin was done. Intracranial meningioma occurred in significantly younger age than spinal ones. Most of spinal meningiomas were of transitional histology. CD10 was expressed in 14% of cases with significant positivity in spinal rather than intracranial cases. Transitional meningiomas showed the highest positivity for CD10 expression, while the least positive was the meningiotheliomatous type. Inhibin was expressed in 6% of cases with no significant relation to clinicopathological and histological features. There was no significant relationship between the expression of CD10 and inhibin expression in meningiomas. In conclusion, spinal meningiomas differ than intracranial ones in many clinicopathological and biological aspects. Among these differences is CD10 expression being more expressed in spinal meningiomas. However CD10 and inhibin are aberrantly expressed in a proportion of meningiomas, both have no relations to poor prognostic factors but more caution should be exerted during usage of these markers in diagnosis of hemangioblastoma and metastatic RCC. Further studies are suggested for exploring more biological differences between spinal and intracranial meningiomas.

Spinal Clear Cell Meningioma: Clinical Study with Long-Term Follow-Up in 12 Patients

BACKGROUND

Clear cell meningioma (CCM) is a rare histologic subtype of meningioma. The features of CCMs have commonly been based on intracranial cases. However, CCMs in the spinal cord are even rarer, and their natural history, management, and prognosis remain ill-defined.

METHODS

From January 2006 to January 2018, 12 patients with spinal CCM were treated in our hospital. The clinical features, radiologic findings, diagnosis, treatment, and outcome of these patients were analyzed retrospectively. Additionally, we performed a review of the reported data on spinal CCMs.

RESULTS

CCMs accounted for 2.8% of all the spinal meningiomas treated in our hospital. The most common localization of this disease was the lumbar region (7 of 12). The mean age at diagnosis was significantly younger than that of patients with spinal meningiomas (28.8 ± 13.4 years vs. 54.0 ± 14.4 years). During the follow-up period, 5 patients (41.7%) experienced tumor recurrence. Kaplan-Meier analysis showed that younger patients had a significantly shorter progression-free survival time than older patients. The review of the reported data showed that 55 cases of spinal CCMs had been reported. Nineteen patients (38.0%) had developed local recurrence, with a 5-year progression-free survival rate of 33.3%.

CONCLUSIONS

Spinal CCMs are extremely rare tumors with a predilection to affect younger patients and have a high recurrence rate. Although gross total resection is considered to be the optimal treatment, radiotherapy could be considered for patients who had undergone subtotal resection or for younger patients, regardless of the extent of removal. Close follow-up of the entire neuraxis for years is crucial.

Clinical Features, Treatment, and Prognostic Factors of 56 Intracranial and Intraspinal Clear Cell Meningiomas

OBJECTIVE

Intracranial and intraspinal clear cell meningiomas (CCMs) are rarely reported because of their extremely low incidence, and the current understanding of CCM is poor. The purpose of this study was to analyze the incidence and the clinical, radiologic, pathologic, and prognostic features of intracranial and intraspinal CCMs.

METHODS

Among 14,310 cases of intracranial and intraspinal meningiomas that were surgically treated between 2006 and 2016 at Beijing Tian Tan Hospital, 56 were chosen for analysis and retrospectively reviewed. To determine which parameters were associated with longer progression-free survival (PFS) and overall survival (OS), statistical analysis was performed.

RESULTS

CCMs accounted for approximately 0.39% of all intracranial and intraspinal meningiomas. Patients with CCM had a mean age of 32.3 years and there was a female predilection (20 males and 36 females). Gross total resection was achieved in 35 cases, and subtotal resection was achieved in 21 cases. All patients were followed up for 10-206 months after surgery. Twenty-six patients experienced tumor recurrence, and the median PFS was 48.0 months. The 1-year, 3-year, and 5-year PFS was 87.5%, 59.8%, and 41.8%, respectively. Twelve patients died of tumor recurrence, and the median OS was not available. The 1-year, 3-year, and 5-year OS was 98.2%, 91.3%, and 65.8%, respectively. Univariate analysis showed that total tumor removal was significantly associated with a better prognosis. Multivariate analysis confirmed only Simpson grade III and IV resection as an independent risk factor for shorter PFS. Radiotherapy mildly improved PFS after both gross total resection and subtotal resection, showing no significant difference because of the small sample size and short follow-up duration.

CONCLUSIONS

CCM is a rare subtype of World Health Organization grade II meningioma. CCM typically involves young patients and shows a female predilection and high recurrence rate. When possible, total resection is the primary and most suitable treatment for CCM. For patients with primary tumors, radiotherapy is recommended after the initial operation regardless of the extent of resection. For patients with disease recurrence, secondary surgery combined with radiotherapy might serve as an effective treatment.

Molecular progression in unusual recurrent non-pediatric intracranial clear cell meningioma

We report a case of a recurrent clear cell meningioma (ccm) in the frontal lobe of the brain of a 67-year-old man. The patient developed three recurrences: at 3, 10, and 12 years after his initial surgery. Histopathology observations revealed a grade 2 ccm with positivity for vimentin and epithelial membrane antigen. Expression of E-cadherin was positive only in the primary tumour and in the first available recurrence. Fluorescence in situ hybridization analyses demonstrated 1p and 14q deletions within the last recurrence. Multiplex ligation-dependent probe amplification studies revealed a heterozygous partial NF2 gene deletion, which progressed to total loss in the last recurrence. The last recurrence showed homozygous deletions in CDKN2A and CDKN2B. The RASSF1 gene was hypermethylated during tumour evolution. In this report, we show the genetic alterations of a primary ccm and its recurrences to elucidate their relationships with the changes involved in the progression of this rare neoplasm.

Clinical features of clear cell meningioma: a retrospective study of 36 cases among 10,529 patients in a single institution

BACKGROUND

Clear cell meningioma (CCM) is a rare subtype of meningioma. We present the largest series of 36 CCMs and evaluate several prognostic factors of patient's clinical outcome.

METHODS

Thirty-six patients with pathologically confirmed CCM among a total of 10,529 meningioma patients were retrospectively reviewed.

RESULTS

CCM constituted 0.3 % of the intracranial meningiomas and 1.4 % of the intraspinal meningiomas. The male-to-female ratio (36 vs 64 %) for CCMs was similar to that for total meningiomas (28 vs 72 %) patients (chi-squared test, p = 0.3). The mean age at diagnosis of CCM patients (29.3 ± 18.4 years) was significantly younger than that of total meningiomas (49.8 ± 11.9 years) patients (t-test, p = 0). During the follow-up, 15 patients (42 %) suffered from tumor recurrence. The recurrence time ranged from 10 months to 12 years, with a median time of 29 months. Kaplan-Meier survival analysis showed that patients after total resection (Simpson grades I and II) had significantly longer progression-free survival (PFS) time than those after subtotal resection (Simpson grades III and IV) (log-rank test, p = 0.006). However, age (≤20 years or >20 years, p = 0.9), gender (p = 0.3), postoperative radiotherapy (p = 0.4), progesterone receptor staining (positivity or negativity, p = 0.2), and Ki-67 index (≤5 % or >5 %, p = 0.4) did not have significant effects on patients' PFS time.

CONCLUSIONS

The proportion of CCM in spinal meningiomas is likely to be much larger than that in intracranial meningiomas. CCMs should be resected totally when possible to decrease the risk of recurrence or prolong patient's PFS time.

Long-term recurrence rates after the removal of spinal meningiomas in relation to Simpson grades

PURPOSE

Simpson grade II removal (coagulation of the dural attachment after gross total removal) of spinal meningioma is considered an acceptable alternative, but increased recurrence after more than 10 years has been reported. More attention must be paid to the long-term surgical outcomes after Simpson grade II removal.

METHODS

A retrospective review was performed for 20 patients (M:F = 5:15; age, 59 ± 9 years) with Simpson grade II removal (mean follow-up period, 12.9 years; range 10.0-17.5). Magnetic resonance (MR) imaging was conducted in 17 patients at 88 ± 52 months (range 12-157). During the same period, Simpson grade I removal (removal of the dural origin) was performed in 21 patients (follow-up, 89 ± 87 months; range 9-316). Radiological recurrence was defined as a visible tumor on a follow-up MR image, and clinical tumor recurrence was defined as the recurrence of symptoms.

RESULTS

At the final follow-up, neurological symptoms had improved in 16/20 patients and remained stable in 4/20. A recurrent tumor was detected in one patient due to increased back pain at 92 months postoperative, but the symptom was stable without surgery until the last follow-up (124 months). The radiological and clinical recurrence-free survival periods were 150 ± 7 months (95 % CI 136-163) and 204 ± 6 months (95 % CI 193-215), respectively. There was no recurrence after Simpson grade I removal, whereas neurological deterioration occurred in two patients after surgery.

CONCLUSIONS

Simpson grade II removal may be an alternative option if the risk of complications with Simpson grade I removal is expected to be high.

A five year-old child with clear cell petro-clival meningioma: case report with clinical and histopathological long-term follow-up

BACKGROUND

Only a few cases have been previously published about clear cell meningiomas in children, the majority of them in the location of the spine. We describe an unusual case of clear cell meningioma occurring at the petro-clival region in a 5-year-old child. We further seek to determine the impact of several growth factors as well as the AKT1 mutation on the tumor growth pattern.

CASE PRESENTATION

A five-year-old girl was presented with a one-week history of cephalgia, ataxia, and left sided torticollis. Magnetic resonance imaging (MRI) revealed a dumbbell-shaped homogeneously petro-clival gadolinium-enhancing mass. A staged operative approach was chosen, and a complete removal of the tumor was achieved. Due to recurrent tumor progression, the child underwent several tumor surgeries and two cranial radiations. None of the treatments were able to stop tumor progression. Consequently, the child died at the age of 14 after further extensive intracranial and extracranial tumor progression. The initial histological examination revealed a clear cell meningioma WHO grade II with an MIB-1 labeling index of <1%, which gradually increased with every recurrence up to 10% by the last progression at the age of 13 years. Analogically, an increasing overexpression of epidermal growth factor receptor (EGFR), the platelet-derived growth factor receptor (PDGFR), and the vascular endothelial growth factor receptor (VEGFR) was observed with each recurrence. The AKT1 (E17K) mutation in the tumor was not detectable in all investigated specimens.

CONCLUSION

Pediatric clear cell meningiomas WHO grade II are very rare. Our data demonstrate the progressive overexpression of EGF-, PDGF-, and VEGF-receptors in each recurrence, providing one of these receptors as targeted therapy in such cases. Further evaluation of these growth factors in clear cell meningioma is required to establish the optimal treatment of these aggressive tumors.

Expression and diagnostic implications of carbonic anhydrase IX in several tumours with predominantly clear cell morphology

AIMS

High expression of carbonic anhydrase IX (CA IX) has been reported in clear cell renal cell carcinoma (ccRCC); few studies have reported CA IX expression in other tumours with predominantly clear cell morphology. The aim of study was to examine the expression and diagnostic implications of CA IX in these latter tumours.

METHODS AND RESULTS

An immunohistochemical study was performed of 159 tumours with predominantly clear cell morphology. The results showed that, in addition to primary (25/25) and metastatic (10/11) ccRCC, CA IX was also expressed in breast (2/2), pulmonary (3/5) and hepatic (1/4) clear cell carcinoma, urothelial carcinoma with clear cell change (3/6), clear cell meningioma (4/6) and ependymoma (2/3), haemangioblastoma (10/10), and clear cell hidradenoma (5/6). However, while strong and diffuse positivity for CA IX was observed in ccRCC, clear cell breast carcinoma, haemangioblastoma, and clear cell hidradenoma, the other cases showed predominantly focal positivity for CA IX. In particular, CA IX staining was often seen at the periphery of necrotic areas.

CONCLUSIONS

Our results indicate that strong and diffuse CA IX expression may be useful for differentiating ccRCC from several clear cell tumours, with the exception of clear cell breast carcinoma, haemangioblastoma, and clear cell hidradenoma.

Value of PAX8, PAX2, napsin A, carbonic anhydrase IX, and claudin-4 immunostaining in distinguishing pleural epithelioid mesothelioma from metastatic renal cell carcinoma

Both mesotheliomas and renal cell carcinomas can present a wide variety of cytomorphologic features and histologic patterns. Because of this, renal cell carcinomas metastatic to the pleura and lung can be confused with mesotheliomas. Recently, a variety of positive carcinoma markers, including kidney-associated markers, have become available. The aim of this study is to investigate the value of some of these markers, specifically PAX8, PAX2, napsin A, carbonic anhydrase IX, and claudin-4, for assisting in distinguishing pleural epithelioid mesotheliomas from metastatic renal cell carcinomas. To do so, a total of 40 pleural epithelioid mesotheliomas and 55 renal cell carcinomas (33 clear cell, 10 papillary, and 12 chromophobe) were investigated. In all, 91% of the renal cell carcinomas expressed claudin-4, 89% PAX8, 60% PAX2, 71% carbonic anhydrase IX, and 29% napsin A. All of the mesotheliomas were positive for carbonic anhydrase IX and were negative for all of the other markers. On the basis of these results, it is concluded that claudin-4 and PAX8 have a higher sensitivity and specificity for assisting in discriminating between pleural epithelioid mesotheliomas and renal cell carcinomas when compared with all of the other positive carcinoma markers that are, at present, recommended to be included in the immunohistochemical panels used in this differential diagnosis. Even though PAX2 and napsin A are highly specific, because of their low sensitivity, they have only a limited value. Carbonic anhydrase IX is not useful.

Neuropathology of brain metastases

Metastatic tumors are the most common neoplasms encountered in the central nervous system (CNS), and continue to be major cause for mortality and morbidity. Macroscopic features and corresponding radiological findings can be diagnostic in majority of the cases, however, microscopic evaluation would be necessary when the differential diagnosis includes a primary CNS tumor, unknown primary tumor site, and when the resection of the tumor is either considered therapeutic or palliative. The first step in the diagnosis of a metastatic brain lesion is to exclude a primary CNS tumor, followed by verification or identification of the primary tumor and the site. Although general approach to a metastatic lesion from an unknown primary tumor is the same everywhere else, there are slight variations for the metastatic lesions in the CNS versus other regions. When morphological features are not enough to establish a definitive diagnosis, additional studies including immunohistochemical stains are applied. With the expending immunohistochemical armamentarium for pathologists, more accurate assessments are possible even in cases of unknown primary tumor. This review summarizes the diagnostic approach to CNS metastases, immunohistochemical assessment of neoplasm of unknown primary, and primary CNS lesions entering in the differential diagnosis of metastases.

Intracranial clear cell meningioma in two children with blood relations: two case reports and literature review

Intracranial clear cell meningioma (CCM) is very rare and often has an aggressive clinical course. The predilection site of intracranial CCM in children was cerebellopontine angle where represents challenging tumor resection because of the vicinity of brainstem, vertebral artery, and lower cranial nerve. Therefore, special consideration is required for this tumor.We report two cases with intracranial CCM in a family and reviewed the literature concerning pediatric intracranial CCM. Case 1 is a 4-year-old boy with a tumor at the right posterior fossa. Case 2 is an 8-year-old boy with a left basilar region tumor. Gross total resection and subtotal resection was achieved in case 1 and case 2, respectively. Case 1 had no tumor recurrence at 12 months after the operation. Case 2 received cyber-knife radiosurgery (CKS) after subtotal resection at 4 months, and the residual tumor had gradually shrunk. Comprehensive chromosomal number aberrations in both patients were revealed by array-comparative genomic hybridization, and loss of neurofibromatosis 2 (NF2) gene was the common genetic abnormality in the two patients.To the best of our knowledge, this is the first report concerned two patients with CCM in a family, and the findings in this article suggest that CKS is a safe and effective adjuvant therapy for residual CCM after operation and NF2 gene mutation plays a role in tumorigenesis of pediatric intracranial CCM.

Clinical features and treatment of World Health Organization grade II and III meningiomas in childhood: report of 23 cases

OBJECT

High-grade meningiomas in childhood are rare, and their clinical features are unknown. The objective of this study was to determine the clinical characteristics and prognosis of childhood high-grade meningiomas.

METHODS

Twenty-three patients with childhood high-grade meningiomas were treated at the Huashan Hospital. Clinical data were collected, tumor samples were reexamined, and prognoses were attained through follow-up visits and telephone interviews. Survival probability was calculated using the Kaplan-Meier method. A 2-sided probability level of 0.05 was chosen for statistical significance.

RESULTS

The series included 18 males and 5 females (mean age 12.1 years). The most common symptoms were headache and vomiting (43%). Three patients had accompanying neurofibromatosis type II (NF2). The high-grade meningioma cases with NF2 had larger tumor diameters than those without NF2 (p = 0.010). The skull base was the most common tumor site (39%). Complete resections were achieved in 11 patients after their initial operations. Adjuvant radiation therapy was performed in 9 cases. Follow-up evaluations were performed for 20 patients (mean follow-up 70 months). Ten patients experienced recurrences, 2 patients had lung metastases, and 7 patients died of the recurrence. The extent of surgery was significantly related to progression-free survival (PFS; p = 0.038). A negative progesterone receptor combined with strongly positive Bcl-2 immunoreactivity was significantly related to PFS (p = 0.001) and overall survival (p = 0.002). The MIB-1 labeling index was significantly related to overall survival (p = 0.018), whereas postoperative radiation therapy was not significantly related to PFS (p = 0.087) and overall survival (p = 0.40).

CONCLUSIONS

Childhood high-grade meningioma is a rare tumor type. Childhood high-grade meningioma has a male predominance and the basilar region is the most common tumor location. Patients with these tumors have high recurrence and mortality rates. The extent of resection is an important prognosis factor. A negative progesterone receptor combined with a strongly positive Bcl-2 immunoreaction might predict cancer recurrence. The MIB-1 labeling index correlates with the prognosis, and an MIB-1 labeling index > 3% increases the risk of recurrence in childhood high-grade meningioma. More cases should be collected, and longer follow-up periods should be obtained, to evaluate the effects of postoperative radiation therapy in childhood high-grade meningioma.

Application of immunohistochemistry in the diagnosis of epithelioid mesothelioma: a review and update

A large number of immunohistochemical markers that can assist in the differential diagnosis of epithelioid mesotheliomas are currently available. Because these markers are expressed differently in the various types of carcinomas that can metastasize to the serosal membranes and can potentially be confused with epithelioid mesothelioma, their selection for inclusion in a diagnostic panel largely depends on the differential diagnosis, as well as on which ones work the best in a given laboratory. Traditionally, the panels used in the differential diagnosis of epithelioid mesothelioma have consisted of a combination of positive mesothelioma markers and broad-spectrum carcinoma markers. At present, a wide variety of organ-associated carcinoma markers such as thyroid transcription factor-1 and napsin A for the lung, PAX 8 and PAX 2 for the kidney, and Müllerian-derived tumors; gross cystic disease fluid protein-15 and mammaglobin for the breast; and CDX2 for intestinal differentiation are available, which can assist in establishing the site of origin of an adenocarcinoma when included in a diagnostic panel. This article provides updated information on the composition of the panels of markers recommended in the various differential diagnoses.

Spinal meningioma in childhood: clinical features and treatment

OBJECT

The purpose of this retrospective study is to determine the clinical characteristics and the prognosis of the spinal meningioma in childhood (under 18 years of age) based on the treatment at our institution.

METHODS

Ten spinal meningioma cases in children were treated during the last 9 years. The clinical data was retrospectively analyzed and the results were compared with those in the literature.

RESULTS

The series included eight males and two females and the mean age was 13.2 years. The most common initial symptoms were pain (6/10) and the common signs were limb weakness (4/10) and gait disturbance (2/10) and distal paresthesia (1/10) and bladder disturbance (1/10). Four patients had other clinical signs of neurofibromatosis type II (NF-2) such as tumors elsewhere. All the tumors were located in cervical and thoracic vertebrae. Resection according to Simpson Grade I (6/10), II (2/10), III (1/10), and IV (1/10) were performed. Grade II meningiomas accounted for 3/10 in this series. All patients were followed up with mean follow-up period of 43 months. Seven patients had recurrence of the tumor in that period and one had died.

CONCLUSIONS

Spinal meningioma is an uncommon pediatric neoplasm and has a poor prognosis. It has a male predominance and is inclined to be associated with NF-2, and those that are associated with higher pathologic subtypes and NF-2 have more unfavorable outcome. Every effort should be made to achieve total removal which may decrease the incidence of recurrence.

Intracranial clear cell meningioma: a clinicopathologic study of 15 cases

OBJECT

Clear cell meningioma (CCM) is a rare histological variant of meningioma. CCM has a high recurrence rate and aggressiveness. In this study, we reviewed our experience in the treatment of the lesion.

METHODS

Here we present a series of 15 patients with intracranial CCM. The clinical data were retrieved from the records of our Neurosurgery Department and the patients' prognoses were attained by clinic service and telephone. Immunohistochemistry for epithelial membrane antigen (EMA), vimentin, glial fibrillary acidic protein (GFAP), CD10, and S-100 was done, and the MIB-1 labeling index was calculated in all cases.

RESULTS

The 15 patients included eight males and seven females; the mean age was 34.8 years. The most frequent initial symptoms were headache and hearing loss. The most common location was the cerebellopontine angle (CPA) zone. Eleven patients had total removal and four patients underwent subtotal removal. Histological features of atypia were present in different proportions, from 6.7% to 100%, and six cases accorded with atypia. Three tumors showed brain invasion. EMA and vimentin were 100% positive, and CD10 was 100% negative. GFAP was 87% negative and S-100 was 93% negative. The mean follow-up period was 36.7 months. Three patients with brain invasion all recurred and five cases with atypia recurred. In 11 patients with total removal, six patients recurred. In four patients with subtotal removal, three patients recurred. Kaplan-Maier analysis showed that incomplete surgical resection was significantly associated with recurrence (p = 0.001). The MIB-1 labeling index for recurrence was 5.7 ± 2.7% versus 2.8 ± 1.5% for no recurrence (p = 0.036).

CONCLUSIONS

CCM is a rare subtype of meningioma, with a tendency to present in younger patients and a propensity to recur. Immunohistochemistry plays a vital role in differentiating CCM from other tumors. Brain invasion, atypia and MIB-1 labeling index are likely to predict the recurrence. The extent of resection might be connected with the prognosis.

The use of immunohistochemistry in the diagnosis of metastatic clear cell renal cell carcinoma: a review of PAX-8, PAX-2, hKIM-1, RCCma, and CD10

The diagnosis of metastatic clear cell renal cell carcinoma may be difficult in some cases, particularly in the small image-guided biopsies that are becoming more common. As targeted therapies for renal cell carcinoma are now standard treatment, the recognition and diagnosis of renal cell carcinoma has become even more critical. Many adjunctive immunohistochemical markers of renal epithelial lineage such as CD10 and RCCma have been proposed as aids in the diagnosis of metastatic renal cell carcinoma, but low specificities often limit their utility. More recently described markers (PAX-2, PAX-8, human kidney injury molecule-1, hepatocyte nuclear factor-1-β, and carbonic anhydrase-IX) offer the potential for greater sensitivity and specificity in this diagnostic setting; however, knowledge of their expected staining in other neoplasms and tissues is critical for appropriate use. In this review, we discuss the most widely used immunohistochemical markers of renal lineage with an emphasis on their sensitivity and specificity for metastatic clear cell renal cell carcinoma. Subsequently, we present a variety of organ-specific differential diagnostic scenarios in which metastatic clear cell renal cell carcinoma might be considered and we propose immunopanels for use in each situation.