Angel Maillo

Early recurrences in histologically benign/grade I meningiomas are associated with large tumors and coexistence of monosomy 14 and del(1p36) in the ancestral tumor cell clone

Tumor recurrence is the major clinical complication in meningiomas, and its prediction in histologically benign/grade I tumors remains a challenge. In this study, we analyzed the prognostic value of specific chromosomal abnormalities and the genetic heterogeneity of the tumor, together with other clinicobiological disease features, for predicting early relapses in histologically benign/grade I meningiomas. A total of 149 consecutive histologically benign/grade I meningiomas in patients who underwent complete tumor resection were prospectively analyzed. Using interphase fluorescence in situ hybridization, we studied the prognostic impact of the abnormalities detected for 11 different chromosomes, together with other relevant clinicobiological and histopathological characteristics of the disease, on recurrence-free survival (RFS) at 2.5, 5, and 10 years. From the prognostic point of view, losses of chromosomes 9, 10, 14, and 18 and del(1p36) were associated with a shorter RFS at 2.5, 5, and 10 years. Similarly, histologically benign/grade I meningiomas showing coexistence of monosomy 14 and del(1p36) in the ancestral tumor cell clone displayed a higher frequency of early relapses. In fact, coexistence of -14 and del(1p36) in the ancestral tumor cell clone, together with tumor size, represented the best combination of independent prognostic factors for the identification of those patients with a high risk of an early relapse. Our results indicate that patients with large histologically benign/grade I meningiomas carrying monosomy 14 and del(1p36) in their ancestral tumor cell clone have a high probability of relapsing early after diagnostic surgery. These findings suggest the need for closer follow-up in this small group of patients.

Intratumoral Patterns of Clonal Evolution in Meningiomas as Defined by Multicolor Interphase Fluorescence in Situ Hybridization (FISH) : Is There a Relationship between Histopathologically Benign and Atypical/Anaplastic Lesions?

Meningiomas are cytogenetically heterogeneous tumors in which chromosome gains and losses frequently occur. Based on the intertumoral cytogenetic heterogeneity of meningiomas, hypothetical models of clonal evolution have been proposed in these tumors which have never been confirmed at the intratumoral cell level. The aim of this study was to establish the intratumoral patterns of clonal evolution associated with chromosomal instability in individual patients as a way to establish tumor progression pathways in meningiomas and their relationship with tumor histopathology and behavior. A total of 125 meningioma patients were analyzed at diagnosis. In all cases, multicolor interphase fluorescence in situ hybridization (iFISH) studies were performed on fresh tumor samples for the detection of quantitative abnormalities for 11 different chromosomes. In addition, overall tumor cell DNA content was measured in parallel by flow cytometry. iFISH studies were also performed in parallel on tissue sections in a subset of 30 patients. FISH studies showed that 56 (45%) of the 125 cases analyzed had a single tumor cell clone, all these cases corresponding to histologically benign grade I tumors. In the remaining cases (55%) more than one tumor cell clone was identified: two in 45 cases (36%), three in 19 (15%), and four or more clones in five cases (4%). Overall, flow cytometric analysis of cell DNA contents showed the presence of DNA aneuploidy in 44 of these cases (35%), 30% corresponding to DNA hyperdiploid and 5% to hypodiploid cases; from the DNA aneuploid cases, 35 (28%) showed two clones and 9 (7%) had three or more clones. A high degree of correlation (r >/= 0.89; P < 0.001) was found between FISH and flow cytometry as regards the overall quantitative DNA changes detected with both techniques, the former being more sensitive. Among the cases with chromosome abnormalities, the earliest tumor cell clone observed was frequently characterized by the loss of one or more chromosomes (64% of all meningiomas); loss of either a single chromosome 22 or, less frequently, of a sex chromosome (X or Y) and del (1p) was commonly found as the single initial cytogenetic aberration (30%, 5%, and 5% of the cases, respectively). Interestingly, an isolated loss of chromosome 22 was only found as the initial abnormality in one out of 14 atypical/anaplastic meningiomas, while the same cytogenetic pattern was present in the ancestral tumor cell clone of 32% of the benign tumors. Cytogenetic patterns based on chromosome gains were found in the ancestral tumor cell clone in 4% of the patients, 2% corresponding to tetraploid tumors. Overall, cytogenetic evolution of the earliest tumor cell clones was frequently associated with tetraploidization (31%). Our results show that meningiomas are genetically heterogeneous tumors that display different patterns of numerical chromosome changes, with the presence of more than one tumor cell clone detected in almost half of the cases including all atypical/anaplastic cases. Interestingly, the pathways of intratumoral clonal evolution observed in the benign tumors were different from those observed in atypical/anaplastic meningiomas, suggesting that the latter tumors might not always represent a more advanced stage of histologically benign meningiomas.

Dissecting aneurysm of the posterior cerebral artery: spontaneous resolution.

Dissecting aneurysms of the intracranial arteries display vascular pathological features that appear sporadically, generally affecting young adults. The clinical features of this condition may involve both ischemic episodes and hemorrhages. Posterior circulation is affected less than the rest of the intracranial arteries, and it is extremely rare to find the posterior cerebral arteries only affected. Mortality is high in patients where the lesion is located in the posterior intracranial circulation, although dissecting aneurysms limited to the posterior cerebral arteries may, to a certain extent, be benign. We report the case of a young woman with ischemia in the territory of the posterior cerebral artery that occurred subsequent to a dissecting aneurysm that resolved spontaneously to a complete remission, both clinically and as demonstrated by angiography. A review of the literature is made, analyzing the pathogenic, clinical, angiographic, and therapeutic characteristics of such lesions.

The Cytogenetic Relationship between Primary and Recurrent Meningiomas Points to the Need for New Treatment Strategies in Cases at High Risk of Relapse

Purpose: Recurrence is the major factor influencing the clinical outcome of meningioma patients although the exact relationship between primary and recurrent tumors still needs to be clarified. The aim of the present study is to analyze the cytogenetic relationship between primary and subsequent recurrent meningiomas developed within the same individual. Experimental Design: Multicolor interphase fluorescence in situ hybridization was done for the identification of numerical abnormalities of 12 chromosomes in single-cell suspensions from 59 tumor samples corresponding to 25 recurrent meningioma patients. In 47 of these tumors, the distribution of different tumor cell clones was also analyzed in paraffin-embedded tissue sections. In parallel, 132 nonrecurrent cases were also studied. Results: Most recurrent meningiomas showed complex cytogenetic aberrations associated with two or more tumor cell clones in the first tumor analyzed. Interestingly, in most individuals (74%), exactly the same tumor cell clones identified in the initial lesion were also detected in the subsequent recurrent tumor samples. In the recurrent tumor samples of the remaining cases (26%), we observed tumor cell clones related to those detected in the initial lesion but which had acquired one or more additional chromosome aberrations associated with either the emergence of new clones with more complex karyotypes or the disappearance of the most representative clones from the primary lesions. Multivariate analysis of prognostic factors showed that the Maillo et al. prognostic score, based on age of patient, tumor grade, and monosomy 14, together with tumor size was the best combination of independent variables for predicting tumor recurrence at diagnosis. Conclusion: Overall, our results indicate that the development of recurrent meningiomas after complete tumor resection is usually due to regrowth of the primary tumor and rarely to the emergence of an unrelated meningioma, underlining the need for alternative treatment strategies in cases at high risk of relapse, particularly those with a high Maillo et al. prognostic score and larger tumors.

Immunophenotypic Identification and Characterization of Tumor Cells and Infiltrating Cell Populations in Meningiomas

Meningiomas are primary tumors of the central nervous system composed of both neoplastic and other infiltrating cells. We determined the cellular composition of 51 meningioma samples by multiparameter flow cytometric (MFC) immunophenotyping and investigated the potential relationship between mRNA and protein expression levels of neoplastic cells. For immunophenotypic, morphologic, and cytogenetic characterization of individual cell populations, a large panel of markers was used together with phagocytic/endocytic functional assays and MFC sorting. Overall, our results revealed coexistence of CD45(-) neoplastic cells and CD45(+) immune infiltrating cells in all meningiomas. Infiltrating cells included tissue macrophages, with an HLA-DR(+)CD14(+)CD45(+)CD68(+)CD16(-/+)CD33(-/+) phenotype and high phagocytic/endocytic activity, and a small proportion of cytotoxic lymphocytes (mostly T CD8(+) and natural killer cells). Tumor cells expressed multiple cell adhesion proteins, tetraspanins, HLA-I/HLA-DR molecules, complement regulatory proteins, cell surface ectoenzymes, and growth factor receptors. Noteworthy, the relationship between mRNA and protein levels was variable, depending on the proteins evaluated and the level of infiltration by immune cells. In summary, our results indicate that MFC immunophenotyping provides a reliable tool for the characterization of the patterns of protein expression of different cell populations coexisting in meningioma samples, with a more accurate measure of gene expression profiles of tumor cells at the functional/protein level than conventional mRNA microarray, independently of the degree of infiltration of the tumor by immune cells.

Gene Expression Profiles of Meningiomas are Associated with Tumor Cytogenetics and Patient Outcome

Cytogenetic analysis is a powerful tool for predicting recurrence in meningiomas, even among histologically benign/grade I tumors. Despite this, no study has been reported in which the impact of tumor cytogenetics on the gene expression profiles (GEP) has been analyzed in meningiomas. Here, we analyzed the GEP of 47 tumors and correlated them with the most clinical relevant cytogenetic subgroups of meningiomas, as confirmed through the analysis of 172 patients. Additionally three normal meningeal samples were also studied.

Microarray-based analysis of spinal versus intracranial meningiomas: different clinical, biological, and genetic characteristics associated with distinct patterns of gene expression.

It has long been recognized that spinal meningiomas show particular clinical and histological features. Here, we compare the clinico-biological characteristics as well as the genetic abnormalities and patterns of gene expression of spinal and intracranial meningiomas. Fourteen spinal and 141 intracranial meningioma patients were analyzed at diagnosis. In all tumors, interphase fluorescence in situ hybridization (iFISH) studies were performed for the detection of quantitative abnormalities for 11 different chromosomes. Additionally, microarray analyses were performed on a subgroup of 18 histologically benign meningiomas (7 spinal and 11 intracranial). Upon comparison with intracranial tumors, spinal meningiomas showed a marked predominance of psammomatous and transitional tumors (p = 0.001), together with a higher proportion of cases displaying a single tumor cell clone by iFISH (p = 0.004). In 86% of the spinal versus 56% of the intracranial tumors (p = 0.01), the ancestral tumor cell clone detected showed either absence of any chromosomal abnormality or monosomy 22/22q-alone. Analysis of gene expression profiles showed differential expression between spinal and intracranial meningiomas for a total of 1555 genes, 35 of which allowed a clear distinction between both tumor types. Most of these 35 genes (n = 30) showed significantly higher expression among spinal tumors and corresponded to genes involved in signal transduction pathways, which did not show a significantly different expression according to tumor histopathology. In summary, we show the occurrence of unique patterns of genetic abnormalities and gene expression profiles in spinal as compared to intracranial meningiomas that provide new insights into the molecular pathways involved in the tumorigenesis and progression of spinal meningiomas, and could help explain their particular clinical and histological features.

Multiple meningiomas of the fourth ventricle in infancy: case report.

Meningiomas are uncommon tumors in infancy. Intraventricular meningiomas do occur more frequently in infancy than in adulthood, although the establishment and growth of such tumors in the fourth ventricle is exceptional in children. The occurrence of multiple meningiomas is currently estimated to be less than 8%. We present the case of a girl who displayed two meningiomas in the fourth ventricle. Five years later, the child had four more meningiomas detected and extirpated from the same site. Eighteen months later, a new tumor appeared in the lower third of the clivus; after resection this was found to be another meningioma. The presence in a child of the repeated occurrence of multiple meningiomas, both in the fourth ventricle and in other areas of the posterior fossa, have led the authors to consider that the case is both curious and rare. Twelve similar cases of meningiomas developing exclusively in the fourth ventricle have been published; of these, only 3 occurred during infancy. A discussion is offered concerning the etiology and pathogenesis of these tumors; in which the possibility of unknown neuro-oncogenic factors that might induce meningiomas is postulated.

Proportion of S‐phase tumor cells measured by flow cytometry is an independent prognostic factor in meningioma tumors

Meningiomas are tumors in arachnoid cells which represent up to one fifth of all intracranial tumors and up to a quarter of spinal neoplasias. Although meningiomas have classically been considered to be benign tumors, it has also been well-established that they show a heterogeneous clinical outcome. To the best of our knowledge no study has yet been performed in which the independent prognostic value of both DNA ploidy and cell cycle has been simultaneously assessed in a large series of meningioma tumors. The aim of the present study was to prospectively explore the prognostic value of DNA ploidy status and the proliferative rate of tumor cells in a series of 105 consecutive meningioma patients studied at diagnosis. Both the presence of DNA aneuploidy and the proportion of S-phase tumor cells were analyzed in all cases in fresh tumors obtained during diagnostic surgery. From the technical point of view, we followed the recommendations of the Consensus Conference on Flow Cytometry DNA Analysis held in October 1992. Our results show that meningioma tumors display a relatively low incidence of DNA aneuploidy (14%), and they usually show a low proliferative rate (mean percentage of S-phase cells of 1.3 +/- 0.3%). The presence of DNA aneuploidy was associated with a higher incidence of aggressive histopathologic subtypes (P = 0.045), a greater age (P = 0.009), location at the cerebral convexity (P = 0.004), and a greater proportion of S-phase cells (P = 0.005). In contrast, no significant association between the DNA ploidy status of meningioma patients and their disease-free survival was found (P = 0. 1). Regarding the proliferative activity of neoplastic cells, we found that a high proportion of S-phase cells (>1.8%) was associated with a significantly lower mean age (P = 0.007), aggressive histopathologic subtypes (P = 0.03), a higher incidence of DNA aneuploidy (P = 0.004), and a significantly shorter disease-free survival (P < 0.004). Multivariate analysis of prognostic factors showed that the proportion of S-phase tumor cells was the most powerful independent prognostic factor in meningioma patients (P = 0.02). In summary, we conclude that the proportion of S-phase tumor cells represents the individual parameter with the highest value for predicting disease-free survival in meningioma patients.

Delineation of commonly deleted chromosomal regions in meningiomas by high-density single nucleotide polymorphism genotyping arrays

Despite recent advances in the identification of the cytogenetic profiles of meningiomas, a significant group of tumors still show normal karyotypes or few chromosomal changes. The authors analyzed the cytogenetic profile of 50 meningiomas using fluorescence in situ hybridization and high‐density (500 K) single nucleotide polymorphism (SNP) arrays. Our results confirm that del(22q) (52%) and del(1p) (16%) (common deleted regions: 22q11.21‐22q13.3. and 1p31.2‐p36.33) are the most frequent alterations. Additionally, recurrent monosomy 14 (8%), del(6q) (10%), del(7p) (10%), and del(19q) (4%) were observed, while copy number patterns consistent with recurrent chromosomal gains, gene amplification, and copy number neutral loss of heterozygosity (cnLOH) were either absent or rare. Based on their overall SNP profiles, meningiomas could be classified into: (i) diploid cases, (ii) meningiomas with a single chromosomal change [e.g., monosomy 22/del(22q)] and (iii) tumors with ≥2 altered chromosomes. In summary, our results confirm and extend on previous observations showing that the most recurrent chromosomal abnormalities in meningiomas correspond to chromosome losses localized in chromosomes 1, 22 and less frequently in chromosomes 6, 7, 14, and 19, while chromosomal gains and cnLOH are restricted to a small proportion of cases. Finally, a set of cancer‐associated candidate genes associated with the TP53, MYC, CASP3, HDAC1, and TERT signaling pathways was identified, in cases with coexisting monosomy 14 and del(1p).