Desmoplastic infantile astrocytoma with atypical phenotype, PTEN homozygous deletion and BRAF V600E mutation

Desmoplastic infantile astrocytoma (DIA) is rare, cystic and solid tumor of infants usually found in superficial cerebral hemispheres. Although DIA is usually benign, uncommon cases bearing malignant histological and aggressive clinical features have been described in the literature. We report a newborn patient who was diagnosed with a DIA and died postresection. Pathologic examination revealed that the main part of the tumor had benign features, but the internal region showed areas with a more aggressive appearance, with higher-proliferative cells, anaplastic GFAP positive cells with cellular polymorphism, necrosis foci, vascular hyperplasia with endothelial proliferation and microtrombosis. Genetic study, performed in both regions of the tumor, showed a BRAF V600E mutation and a homozygous deletion in PTEN, without changes in other relevant genes like EGFR, CDKN2A, TP53, NFKBIA, CDK4, MDM2 and PDGFRA. Although PTEN homozygous deletions are described in gliomas, the present case constitutes the first report of a PTEN mutation in a DIA, and this genetic feature may be related to the malignant behavior of a usually benign tumor. These genetic findings may point at the need of further and deeper genetic characterization of DIAs, in order to better understand the biology of this tumor and to obtain new prognostic approaches, a better clinical management and targeted therapies, especially in malignant cases of DIA.

Whole-exome sequencing, EGFR amplification and infiltration patterns in human glioblastoma

Glioblastoma (GBM) is the most common malignant primary brain tumor in adults. This cancer shows rapid, highly infiltrative growth, that invades individually or in small groups the surrounding tissue. The aggressive tumor biology of GBM has devastating consequences with a median survival of 15 months. GBM often has Epidermal Growth Factor Receptor (EGFR) abnormalities. Despite recent advances in the study of GBM tumor biology, it is unclear whether mutations in GBM are related to EGFR amplification and relevant phenotypes like tumor infiltration. This study aimed to perform whole-exome sequencing analysis in 30 human GBM samples for identifying mutational portraits associated with EGFR amplification and infiltrative patterns. Our results show that EGFR-amplified tumors have overall higher mutation rates than EGFR-no-amplified. Six genes out of 2029 candidate genes show mutations associated with EGFR amplification status. Mutations in these genes for GBM are novel, not previously reported in GBM, and with little presence in the TCGA database. GPR179, USP48, and BLK show mutation only in EGFR-amplified cases, and all the affected cases exhibit diffuse infiltrative patterns. On the other hand, mutations in ADGB, EHHADH, and PTPN13, were present only in the EGFR-no-amplified group with a more diverse infiltrative phenotype. Overall, our work identified different mutational portraits of GBM related to well-established features like EGFR amplification and tumor infiltration.

Identification of a Novel BRCA1 Alteration in Recurrent Melanocytoma Resulting in Increased Proliferation

Primary meningeal melanocytomas are rare tumors of the central nervous system. Although they are considered benign neoplasms, some reports describe recurrent rates up to 45%. Little is known about their genetic and epigenetic landscape because of their infrequency. Even less has been described about markers with prognostic value. Here we describe a patient who developed a primary meningeal melanocytoma, suffered 3 recurrences in a period of 6 years and died of the tumor. The genetic and epigenetic changes explored confirmed GNAQ mutation as an initiating event. We found an epigenetic alteration of GSTP1, a feature that has recently been described in meningiomas, from the beginning of the disease. In addition, there was loss of heterozygosity in BRCA1 beginning in the second recurrence that was linked to an increase in the proliferation index; this suggested a progression pathway similar to the one described in uveal melanomas. These findings underscore the necessity of further research focused on these tumors.

Cytocompatibility and bioactive properties of the new dual-curing resin-modified calcium silicate-based material for vital pulp therapy

OBJECTIVE

The aim of the present study was to evaluate the in vitro biocompatibility of Theracal PT, Theracal LC, and MTA Angelus, considered as bioactive materials used for vital pulp treatment, on human dental pulp stem cells (hDPSCs).

MATERIALS AND METHODS

Human dental pulp stem cells (hDPSCs) were isolated from third molars, and material eluates were prepared (undiluted, 1:2, and 1:4 ratios). The hDPSC cytotoxicity, adhesion, morphology, viability, and cell migration were assessed. The mineralization nodule formation was determined by Alizarin red S staining (ARS). The odonto/osteogenic differentiation potential was assessed by osteo/odontogenic marker expression real-time qPCR. The chemical composition and ion release of the vital pulp materials were determined by energy dispersive X-ray (EDX) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Statistical differences were assessed by ANOVA and Tukey's test (p < 0.05).

RESULTS

The three vital pulp materials showed variable levels of calcium, tungsten, silicon, and zirconium release and in their chemical composition. Cytocompatibility assays revealed higher hDPSC viability and migration rates when treated with Theracal PT than with Theracal LC. The lowest cell adhesion and spreading were observed in all Theracal LC-treated groups, whereas the highest were observed when treated with MTA. Theracal PT and MTA promoted the upregulation of DSPP and RUNX2 gene expression (p < 0.05). After 21 days, both MTA Angelus and Theracal PT-treated cells exhibited a significantly higher mineralized nodule formation than the negative control (p < 0.05).

CONCLUSIONS

This study demonstrates the favorable in vitro cytocompatibility and bioactive properties of the recently introduced Theracal PT and the well-established MTA Angelus on hDPSCs, as opposed to Theracal LC. More studies, including in vivo animal testing are suggested before these new formulations might be used in the clinical setting.

CLINICAL RELEVANCE

Theracal PT is a new material that could be clinically suitable for vital pulp therapy. Further studies considering its biocompatibility and bioactivity are necessary.

The Status of EGFR Modulates the Effect of miRNA-200c on ZEB1 Expression and Cell Migration in Glioblastoma Cells

Migration of glioblastoma cells into surrounding tissue is one of the main features that makes this tumor incurable. We evaluated whole-genome miRNA expression profiling associated with different EGFR amplification patterns in 30 cases of primary glioblastoma. From the 64 miRNAs that showed differential expression between tumors with a high level of EGFR amplification and tumors without EGFR amplification, 40% were related with cell migration, being miR-200c the most differentially expressed between these two groups. We investigated the effect of miR-200c on ZEB1 expression and cell migration in an in vitro transfection model with a miR-200c mimic, a miR-200c inhibitor and siRNA targeting EGFR in three short-term cultures with different levels of EGFR amplification obtained from resected glioblastomas. The cell culture with the highest EGFR amplification level presented the lowest miR-200c expression and the status of EGFR modulated the effect of miR-200c on ZEB1 expression. Silencing EGFR led to miR-200c upregulation and ZEB1 downregulation in transfected cultures, except in the presence of high levels of EGFR. Likewise, miR-200c upregulation decreased ZEB1 expression and inhibited cell migration, especially when EGFR was not amplified. Our results suggest that modulating miR-200c may serve as a novel therapeutic approach for glioblastoma depending on EGFR status.

Somatic copy number alterations are associated with EGFR amplification and shortened survival in patients with primary glioblastoma

Glioblastoma (GBM) is the most common malignant primary tumor of the central nervous system. With no effective therapy, the prognosis for patients is terrible poor. It is highly heterogeneous and EGFR amplification is its most frequent molecular alteration.

In this light, we aimed to examine the genetic heterogeneity of GBM and to correlate it with the clinical characteristics of the patients. For that purpose, we analyzed the status of EGFR and the somatic copy number alterations (CNAs) of a set of tumor suppressor genes and oncogenes.

Thus, we found GBMs with high level of EGFR amplification, low level and with no EGFR amplification. Highly amplified tumors showed histological features of aggressiveness. Interestingly, accumulation of CNAs, as a measure of tumor mutational burden, was frequent and significantly associated to shortened survival. EGFR-amplified GBMs displayed both a higher number of concrete CNAs and a higher global tumor mutational burden than their no EGFR-amplified counterparts. In addition to genetic changes previously described in GBM, we found PARK2 and LARGE1 CNAs associated to EGFR amplification. The set of genes analyzed allowed us to explore relevant signaling pathways on GBM. Both PARK2 and LARGE1 are related to receptor tyrosine kinase/PI3K/PTEN/AKT/mTOR-signaling pathway. Finally, we found an association between the molecular pathways altered, EGFR amplification and a poor outcome.

Our results underline the potential interest of categorizing GBM according to their EGFR amplification level and the usefulness of assessing the tumor mutational burden. These approaches would open new knowledge possibilities related to GBM biology and therapy.

Characterization of a new glioblastoma cell line, GB-val4, with unusual TP53 mutation

A novel cell line derived from a human glioblastoma (GB), named GB-val4, has been established and characterized. GB-val4 cells were hyperdiploid, with many numerical and structural chromosomal rearrangements. The cell line did not show mutations in IDH1/IDH2 genes or EGFR amplification, but it presented two missense mutations in TP53, which imply a very low p53 protein activity within the cell line. Cells also had gain of TP73 copies, hypermethylation of APC, CASP8 and RASSF1, increased expression of ARF1, CDH1 and NF-κB and decreased expression of CDKN2A. Tumorigenity was demonstrated by transplant of GB-val4 cells into athymic nude mice, where solid tumors were grown. Interestingly, a high percentage of GB-val4 cells presented expression of GSC markers CD133 or CD44. These GSC markers were increased in neurosphere cultures, which better mimic solid tumor conditions and maintain the genetic features of the tumor cells. In this study, we aimed to define the characteristics of this novel cell line and its applications in human cancer research. With its genetic features and a poor p53 activity, GB-val4 cells resemble GB tumors. Moreover, the important presence of GSCs in adherent cultures and especially in neurosphere cultures makes GB-val4 an attractive tool to study cancer stem cells, deepen in the knowledge the molecular pathways of GB and develop new therapeutic strategies for patients with these tumors.

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.

Histologic and Cytogenetic Patterns in Benign, Atypical, and Malignant Meningiomas

Atypical meningiomas comprise an intermediate category of meningeal neoplasmas with some microscopic features of aggressivity and a capacity for recurrence. We present a clin ical, morphologic, and cytogenetic study of 15 meningiomas. Morphologic and cytogenetic analysis suggested the existence of morphologically typical meningiomas with normal karyotype or monosomy 22 and morphologically atypical meningiomas, with increasing chromosomal abnormalities (complex karyotype) between these two types. Present results suggest the existence of a third type of morphologically typical meningioma that lacks a phenotypical aggressivity but has a complex karyotype. These genotypical characteristics may be related to the aggressivity of these neoplasms. Int J Surg Pathol 2(4):301-310, 1995

Arterial and venous endothelia display differential functional fractalkine (CX3CL1) expression by angiotensin-II

OBJECTIVE

Angiotensin-II (Ang-II) promotes the interaction of mononuclear cells with arterioles and neutrophils with postcapillary venules. To investigate the mechanisms underlying this dissimilar response, the involvement of fractalkine (CX(3)CL1) was explored.

METHODS AND RESULTS

Enhanced CX(3)CL1 expression was detected in both cremasteric arterioles and postcapillary venules 24 hours after Ang-II intrascrotal injection. Arteriolar leukocyte adhesion was the unique parameter significantly reduced (83%) in animals lacking CX(3)CL1 receptor (CX(3)CR1). Human umbilical arterial and venous endothelial cell stimulation with 1 μmol/L Ang-II increased CX(3)CL1 expression, yet neutralization of CX(3)CL1 activity only significantly inhibited Ang-II-induced mononuclear cell-human umbilical arterial endothelial cell interactions (73%) but not with human umbilical venous endothelial cells. The use of small interfering RNA revealed the involvement of tumor necrosis factor-α in Ang-II-induced CX(3)CL1 upregulation and mononuclear cell arrest. Nox5 knockdown with small interfering RNA or pharmacological inhibition of extracellular signal-regulated kinases1/2, p38 mitogen-activated protein kinase, and nuclear factor-κB also abolished these responses. Finally, when human umbilical arterial endothelial cells were costimulated with Ang-II, tumor necrosis factor-α, and interferon-γ, CX(3)CL1 expression and mononuclear cell adhesiveness were more pronounced than when each stimulus was provided alone.

CONCLUSIONS

These results suggest that Ang-II induces functional CX(3)CL1 expression in arterial but not in venous endothelia. Thus, targeting endothelial CX(3)CL1-mononuclear leukocyte CX(3)CR1 interactions may constitute a new therapeutic strategy in the treatment of Ang-II-associated cardiovascular diseases.

Characterization of a new human melanoma cell line with CD133 expression

A novel human malignant melanoma cell line, designated MEL-RC08, was established from a pericranial metastasis of a malignant melanoma of the skin. The cell line has been subcultured for more than 150 passages and is tumorigenic in nude mice. Growth kinetics, cytogenetics, flow cytometry, and molecular techniques for analysis of the genes implicated in cell cycle control; mutations in BRAF, NRAS, C-KiT, RB, and TP53 genes; and amplification of MDM2, CDK4, and cyclin D1 have been studied. Cytogenetically, the tumor and the cell line showed a hypertriploid karyotype with many clonal numeric and structural abnormalities. DNA flow cytometry showed an aneuploid peak with a DNA index value of 1.5. Mutations in TP53 and BRAF genes were demonstrated in both tumor and cell line. Furthermore, stem cell marker CD133 expression was detected in most cells, together with other stem cell markers, suggesting the presence of cells with tumor-initiating potential in this cell line.

Demethylnobiletin inhibits delayed-type hypersensitivity reactions, human lymphocyte proliferation and cytokine production

BACKGROUND AND PURPOSE

Our aim was to examine the effect of demethylnobiletin on various experimental models of delayed-type hypersensitivity (DTH) reactions and to determine its influence on the mediators and enzymes involved in these reactions.

EXPERIMENTAL APPROACH

DTH was induced in mice by oxazolone, dinitrofluorobenzene (DNFB) and sheep red blood cells (SRBC). The effect of demethylnobiletin on the ensuing DTH was studied, especially in relation to oedema formation, cell infiltration and tissue damage. Its activity on different mediators implicated in DTH reactions was also determined and its effect on nitric oxide synthase (NOS)-2 analysed. Finally, its influence on T lymphocyte proliferation, apoptosis and caspase 3 activity was tested.

KEY RESULTS

DTH reactions were all reduced by demethylnobiletin. The experimental results suggest that the compound may act by reducing cell infiltration and by suppressing mediators such as interleukin-2 (IC50=1.63 microM), interleukin-4 (IC50=2.76 microM), tumour necrosis factor-alpha (IC50=0.66 microM), interferon-gamma (IC50=1.35 microM), and interleukin-1 beta (46% at 2.5 microM) and by concomitantly increasing the production of the anti-inflammatory cytokine, interleukin-10. In addition, while demethylnobiletin affected nitric oxide production, it did not modify NOS-2 expression. Finally, demethylnobiletin inhibited proliferation of T cells and induced their apoptosis.

CONCLUSIONS AND IMPLICATIONS

Demethylnobiletin decreased DTH reactions induced by various agents. This finding, along with the fact that the compound has a low toxicity and exhibits several other interesting properties, could pave the way for other structurally related citroflavonoids to be used as pharmacological agents in complementary therapies.

New insight into the inhibition of the inflammatory response to experimental delayed-type hypersensitivity reactions in mice by scropolioside A

Scropolioside A, an iridoid isolated from Scrophularia auriculata ssp. pseudoauriculata, showed anti-inflammatory properties against different experimental models of delayed-type hypersensitivity. This iridoid reduced the oedema induced by oxazolone by 79% (72 h) at 0.5 mg/ear while reducing that induced by sheep red blood cells by 47% (18 h), 45% (24 h) and 36% (48 h) at 10 mg/kg. In vivo it reduced both oedema formation and cell infiltration whereas in vitro it reduced the proliferation of activated T-lymphocytes (IC50 of 67.74 microM). Treatment with scropolioside A (100 microM) 18 and 24 h after phytohemagglutinin stimulation increased the number of cells arrested in the subG(0) phase whereas treatment 3 h after stimulation clearly increased the number of cells that passed to the S phase. Scropolioside A also inhibited the production of prostaglandin E2, leukotriene B4, nitric oxide, interleukin-1beta, interleukin-2, interleukin-4, tumour necrosis factor-alpha and interferon-gamma, but had no effect on the production of interleukin-10. Moreover, it modified the expression of both nitric oxide synthase-2 and cyclooxygenase-2, as well as the activation of nuclear factor-kappaB in RAW 264.7 macrophages.

Deregulation of the G1 to S-phase cell cycle checkpoint is involved in the pathogenesis of human osteosarcoma

Osteosarcoma (OS) displays complex karyotypes with numerical changes as well as structural abnormalities suggesting that several oncogenes and tumor suppressor genes may be implicated in the biology of OS. The aim of our study was to investigate the possible implication of the molecular alterations of the G1 to S-phase checkpoint genes in the pathogenesis of OS. We analyzed samples from 29 patients and found molecular alterations of the RB and TP53 genes in 6 (21%) and 3 (10%) cases, respectively. Homozygous deletion of the INK4A/ARF locus and methylation of INK4A was detected in 3 (10%) and 2 (7%) cases, respectively. CDK4 and MDM2 co-amplification was observed in 1 case (3%). Cyclin D3 is differentially expressed in a greater proportion than D1- and D2-type cyclins. Cytogenetically, all cases had complex karyotypes being especially significant the losses of the chromosomes 4, 13, and 17. As a whole, 11 of 29 (38%) analyzed OS presented alterations in some of the analyzed G1 to S-phase checkpoint genes. These alterations were more frequently present in adults (P = 0.032). All patients with genetic alterations in the G1/S-phase checkpoint died during their clinical follow-up, whereas more than 53% of the remaining cases were alive in this period (P = 0.007). Hence, in the pathogenesis of human OS, deregulation of the G1/S checkpoint genes, especially RB, TP53, and INK4/ARF locus, plays an important role and defines a subgroup of patients with a poor outcome.

Cytogenetic and molecular findings related to rhabdomyosarcoma. An analysis of seven cases

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in childhood. Histologically, it is subdivided histologically into two main subtypes: alveolar (ARMS) and embryonal (ERMS). ARMS is characterized by t(2;13)(q35;q14) or its variant t(1;13)(p36;q14), which fuse PAX3 and PAX7, respectively, with FKHR to produce chimeric genes. ERMS is frequently associated with loss of heterozygosity of 11p15.5. We investigated seven RMS (three ARMS and four ERMS) by means of cytogenetic, fluorescence in situ hybridization, and molecular analyses, including the study of the main genes implicated in the G1- to S-phase cell cycle transition, and correlated these studies with pathologic findings and clinical outcome. All tumors showed clonal, numerical, and structural chromosomal abnormalities. Two ARMS had the t(2;13)(q35;q14) and the third a PAX7/FKHR fusion, a cryptic t(1;13)(p36;q14), undetected by cytogenetic techniques, but revealed by reverse transcriptase polymerase chain reaction. One ERMS showed a der(11)t(3;11)(p21;p15) as a sole structural anomaly. Gene amplification was seen in four tumors, as double minutes or in the form of homogeneously staining regions. Overexpression of MYCN oncogene was found in two ARMS; N-myc DNA probe detected oncogene amplification located on the double minutes of these cases. Analysis of the regulatory genes responsible for G1- to S-phase transition showed a homozygous deletion of the 9p21 locus genes in a spindle-cell ERMS.

[Oligoastrocytoma with signet-ring cell differentiation. A morphological, ultrastructural and immunohistochemical study]

We present a case of a mixed glial tumor (oligoastrocytoma) with signet-ring cells. This cellular feature is a rare differentiation in glial tumors of the central nervous system. Histological, immunohistochemical and ultrastructural findings have been analyzed. Signet-ring cells showed intense expression with GFAP, S-100 and vimentin. A differential diagnosis with other primary brain tumors and cerebral metástases with signet-ring cell differentiation was discussed.

Meningioma: Un modelo de evolución citogenética en la iniciación y progresión tumoral

Meningiomas are tumors of the central nervous system with a great morphological heterogeneity. They are generally benign, and have the capacity to progress to a higher histological grade (atypical and anaplastic), which is associated with an increase in biological aggressivity and/or capacity to recur. Citogenetically this evolution is characterized by total or partial monosomy 22 in the early phase, continued by numerical and structural changes during tumor progression. In this study, we present a review of 85 cases of meningiomas: 43 benign, 28 atypical and 14 anaplastic. We study the clinical and histopathological features, and their correlation with cytogenetie abnormalities present in these tumors. Numerical aberrations such as monosomy of chromosome 10, 14 and 18, and structural abnormalities such as deletions on 1p are directly associated with a higher agressivity of tumors. An association of aberatons on 1p and chromosome 14 are more commonly found in atypical and anaplastic meningiomas. These facts imply that the presence of complex karyotypes progressively increases from grade I to grade III meningiomas. Furthermore, these karyotypes are common in recurrent tumors.

[Monosomy 1p and alkaline phosphatase in meningiomas. Citopathological, histochemical and genetical study in 10 tumors]

BACKGROUND

Cytogenetic studies in meningiomas show that 1p monosomy constitutes an important factor involved in their progression. Genes coding for unspecific alkaline phosphatase (AP-un) are located in this chromosome, in particular in 1p34-p36.1. This enzyme is widely distributed in the body and it is also found in meningiomas. The loss of expression of this enzyme in meningiomas has been associated with the presence of 1p monosomy in these tumors.

PATIENTS AND METHOD

We studied 10 meningiomas from 8 patients which shared 1p monosomy. Three tumors had a benign morphologic pattern; it was atypical in two and malignant in five cases. We performed a cytogenetic study and FISH as well as a determination of AP-un in tumor cells.

RESULTS

In 8 of ten cases, a loss of AP-un expression was observed. One case displayed positivity in 20% cells. In a positive case, activity was demonstrated in 80% cells.

CONCLUSIONS

Our work aimed at analysing the relationship between loss of expression of AP-un, 1p monosomy and the aggressiveness of meningioma. Our results back the interest in determining this enzyme in tumor cells as a quick method with important prognostic value.

Diffuse type of giant-cell tumor of tendon sheath: an ultrastructural study of two cases with cytogenetic support

Two cases of the diffuse type of giant-cell tumor of the tendon sheath (GCTTS) are described. Both tumors arose in the vicinity of large joints of the lower extremity, showing similar clinical and radiological features. Histologically, a proliferation of polygonal mononuclear cells was seen, together with osteoclastlike giant cells, foam cells, and siderophages. The tumors were poorly delineated, displaying an infiltrative pattern into the neighboring soft tissues. Immunohistochemically, strong expression of vimentin, neuron-specific enolase, A1-antitrypsin, and CD68 was found in both mono- and multinucleated tumor cells. At the ultrastructural level, mononuclear cells revealed a diverse morphology, displaying features of histiocytelike and fibroblastlike cells, with the former being more numerous. Scarce neurosecretorylike granules, made up of electrondense membrane-bound material, were found in the cytoplasm of the mononuclear cells. Cytogenetic analysis of one case shows the presence of a clonal population with 47 chromosomes and two different translocations, t(2;3) and der(8) t(8;12). Present findings provide further support regarding the neoplasic nature of this tumoral entity.

Loss of 1p in recurrent meningiomas

Deletion of 1p is associated with histological progression to meningiomas. Detection of this alteration may be a predicting factor for recurrences in this tumor. We present 8 meningiomas from four patients: the original tumor and the first recurrence in one patient, and the first and second recurrences in the other three were studied. We compared results of monosomy 22 and deletion of chromosome 1p with cytogenetic methods and fluorescence in situ hybridization (FISH) analysis obtained from slides of direct preparations, of cultured cells and slides of touch preparations. The cytogenetic study showed normal chromosome 22 and deletion on 1p32 in both samples of one patient; only monosomy 22 in both recurrences in another patient, and normal karyotypes with different non-clonal anomalies in the other tumors. However, with FISH analysis, monosomy 22 in both recurrences of three patients was demonstrated, as well as the loss of 1p in all tumors. These results were more evident in the analysis of direct and touch preparations than in those of cultured cells.

Histopathological and cytogenetic findings in benign, atypical and anaplastic human meningiomas: a study of 60 tumors

Meningiomas may display benign (grade I), atypical (grade II) and anaplastic (grade III) histopathological findings. The cytogenetic studies strongly suggest that secondary changes (beyond loss of chromosome 22) appear to be associated with more atypical features and with greater clinical aggressivity. We studied 60 tumors from 52 patients. Histopathological features such as nuclear pleomorphism, nucleolar prominence, mitosis, necrosis, cellular density, PCNA labeling index, and karyotype have been evaluated. The distribution in histological grades was: 50% benign, 33% atypical and 17% anaplastic meningiomas. Nuclear pleomorphism and nucleolar prominence showed a progressive increase in grades I, II and III. Multifocal micronecrosis was considered a criterion of malignancy. A significant correlation was observed between PCNA-LI, mitotic index and grades. Complex karyotypes increased progressively: benign (34% of cases), atypical (45% of cases) and anaplastic (70% of cases). The most common numerical alterations were losses of chromosomes 10, 14, 18 and 22. The chromosomes most often involved in structural anomalies were: 1, 4, 7, 14 and 22. Telomeric associations were present in four cases and double minutes in two cases. Prognostic criteria for these tumors have been analyzed on the basis of these data.

Endometrial stromal sarcomas: immunohistochemical, electron microscopical and cytogenetic findings in two cases

Uterine sarcomas are approximately 3% of all malignant uterine corpus tumours. Of these, the tumours that originate solely in the stromal elements of the uterine wall are infrequent and have not been well characterized cytogenetically. We report two cases of endometrial stromal sarcomas (ESS), one low grade and one high grade, diagnosed by conventional histology, immunocytochemistry, electron microscopy and cytogenetics. Morphologically clear-cut differential structures were seen at optical, immunohistochemical, and electron microscopic levels, permitting a clear differential diagnosis. The low-grade ESS expressed hormonal receptors and vimentin, whereas the high-grade ESS showed no hormone receptors, high Ki-67 activity, and occasional cytokeratin-positive cells. Ultrastructurally, no malignant epithelial differentiation was seen in the tumour cells, but cilia were found in both cases. Cytogenetic study of the low-grade ESS showed pseudodiploid karyotype with chromosomes 6 and 20 rearranged. The high-grade ESS showed a complex karyotype with clonal numerical and structural anomalies. The chromosomes involved in the structural rearrangements were 1, 3, 6, 7, 13, 14, 15, 17, 19, and 21.

New type of chimeric fusion product between the EWS and ATFI genes in clear cell sarcoma (malignant melanoma of soft parts)

We report a new case of clear cell sarcoma (CCS) harboring the t(12;22)(q13;q12). Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the presence of a chimeric transcript between the EWS and ATFI genes, both in primary and metastatic tissue. Sequencing studies disclosed an in-frame fusion between EWS gene codon 265 and ATFI gene codon 110. This breakpoint has not been reported previously and indicates an important in vivo loss of EWS and ATFI gene domains, which could be associated with the unusually aggressive behavior of this tumor.

[Meningiomas with disomy of chromosome 22: study of 9 cases]

BACKGROUND

Cytogenetic studies of meningiomas suggest that loss of (or parts of) chromosome 22 is a primary event in the development of these tumors; later on, other chromosomal changes would occur in the caryotypes. All these secondary changes are observed mainly in cases with high clinical aggressivity. However, in a few cases of meningiomas disomy 22 coexists, but with other chromosomic anomalies. We present clinical, histopathological and cytogenetic findings in a group of meningiomas with disomy of chromosome 22.

PATIENTS AND METHODS

We collected 10 meningiomas from nine patients which ages ranged between 28-70 years. Fresh tumoral specimens were divided for histologic examination and cytogenetic study, performed after short-term culture.

RESULTS

At microscopic examination 5 tumors were classified as benign meningiomas, four as atypical and one as malignant meningioma. Four cases were recurrent tumors. The cytogenetic studies showed that all tumors presented two chromosomes 22 and other chromosome abnormalities. Losses in chromosomes 4, 7, 10, 14, 16, 17 and 20 were frequent; cytogenetics rearrangements of chromosomes 1, 4, 5, 7, 14, 19 and 22 were frequently involved.

CONCLUSIONS

In karyotypic evolution of meningiomas, secondary anomalies of chromosomes 1p, 10 and 14 are the most common and appear to be associated with a more aggressive clinical course. In this group of meningiomas with disomy 22, these anomalies were also frequently found, and were related in 50% of cases with atypical or malignant morphologies and of them with recurrent tumors in the 40%.

Evolution to malignancy in a recurrent meningioma: morphological and cytogenetic findings

The original tumor and 4 relapses of a recurrent meningioma were studied. We analyzed and compared these recurrences by histopathology, PCNA labelling index (PCNA-LI), nuclear count, and cytogenetical findings. The most important changes in the evolution to aggressivity were: recurrences at progressively shorter intervals, increases in the PCNA-LI, and micronecrosis; histological changes such as sheeting and increase of the extracellular matrix and a gradual transformation to a clonally complex karyotype.

Cytogenetic findings in malignant mixed mesodermal tumors of the uterus

Cytogenetic analyses of four malignant mixed mesodermal tumors (MMMT) of the uterus are reported, of which one was of the homologous type and three of the heterologous. Karyotypic analyses were obtained in two cases from original tumors and in two cases from tumors xenotransplanted into nude mice. The karyotype of the homologous MMMT was normal in three different passages of a nude mice xenograft line established from the primary tumor. The heterologous tumors showed normal karyotype in one case and hyperdiploid and near triploid range with extensive numerical and structural rearrangements in two cases. Deletion of chromosome 1 at p32, and deletion of chromosome 11 at q13 were common markers in anomalous cases. The chromosomes most often involved in structural rearrangements were chromosomes 1, 9, 11, 12, 17, and 19. Double minutes, homogeneously staining regions, and telomeric association were also seen.

Involvement of the long arm of chromosome 9 in medulloblastoma in an adult

Medulloblastoma is the most common primitive neuroectodermal tumor (PNET) in children, but is very rare in adults. An isochromosome for the long arms of 17, i(17q), is found in about 30% of pediatric cases. Cytogenetic studies in adults are very scarce; only six cases have been described cytogenetically: three cases had normal karyotype, two were studied partially, and another presented only two clonal structural anomalies: del(9)(q12) and del(11)(q22). We studied the chromosomes from medulloblastoma in a 27-year-old woman and found one hypotetraploid stemline with clonal alterations. In the structural anomalies, chromosomes 3, 9, 12, and i(17q) were involved. Chromosome 9 presented a deletion in the long arm, del(9)(q13), with consequent loss of the 9q13-->qter region. This anomaly was similar to one found in a previous case. We suggest that the partial loss of the long arm of chromosome 9 may be a characteristic change of adult medulloblastoma.

Presence of double minutes and monosomy 17p in xenografted human osteosarcomas

Cytogenetic analysis of 8 cases of xenografted human osteosarcomas are reported, including six newly diagnosed and two recurrent tumors. Histologically five were osteoblastic, two were chondroblastic, and one was the microcellular type. All tumors were studied in short-term primary cultures between two and six days. Clonal and nonclonal abnormalities were present in the eight cases; four had a chromosome number in the hypotriploid range, two in the hyperdiploid, one in the hypodiploid, and one in the hypertetraploid range. All cases had complex karyotypes and the recognizable structural rearrangements clustered to chromosome arms 1p, 1q, 3p, 5p, 6q, 11p, 13p, 14p, 15q, 16p, 16q, 20q, 21p, and 22q. Seven cases presented double monosomy 17 and six tumors showed double minutes (dmin) or a homogeneously staining region (hsr). This fact has been described recently and its relation with the amplification of the MDM2 gene observed in osteosarcomas is as yet unknown.

Cytogenetical findings of recurrent meningiomas. A study of 10 tumors

Cytogenetic analyses of 10 cases of recurrent meningiomas growing in culture between 1-10 days are reported, of which seven showed benign morphology, one atypical, and two, malignant features. Normal karyotypes with nonclonal alterations were found in three cases, one case with only monosomy 22, and complex karyotypes in the remaining six. Four cases were hypodiploid, one pseudodiploid, and one hyperdiploid. The chromosomes most often involved in structural rearrangements were 1, 7, and 14 and the losses were chromosomes 7, 10, 14, 15, 18, and 22. Ring chromosome, dicentrics, double minutes, and association between satellites were found in one case. These complex karyotypes with hypodiploidy, structural rearrangements, and other markers in recurrent meningiomas may indicate aggressive tumor characteristics.

Cytogenetic findings in a new case of adenoid cystic carcinoma arising in sphenoidal sinus

We studied a case of adenoid cystic carcinoma. Cytogenetic analysis was performed on short-term culture, and the karyotype revealed only an abnormal cell line with the following changes: partial trisomy 5q, 6q deletion, monosomy of chromosome 9,der(10)t(10;15), a possible ring chromosome 22, and loss of the Y chromosome. The implication of chromosomes 6 and 9 is considered in relation to the karyotypic evolution of this type of tumor.

Cytogenetic study of angiosarcoma of the breast

Angiosarcoma of the breast is quite rare, and the development of cutaneous angiosarcoma after segmental mastectomy and radiation therapy is even less common. A cytogenetic analysis of a mammary angiosarcoma arising in a breast after previous irradiation and segmental mastectomy for infiltrating ductal carcinoma revealed multiple clonal rearrangements involving chromosomes X, 1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 17, 20, and 22. No cytogenetically analyzed angiosarcomas of the breast have been reported before.

Case of meningioma with del(1)(p32) as sole anomaly

We studied a case of typical syncytial meningioma. Cytogenetic analysis of the tumor cells showed a karyotype with normal chromosomes 22 and only one anomaly, del(1)(p32). Cases of meningiomas with normal chromosomes 22 and other anomalies are rare, and it is difficult to correlate their histologic characteristics and biologic behavior.

Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study

Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective chromosomal modes. However, no correspondence between chromosomal modes and mean nuclear area was found. Chromosomal markers have been identified that particularly affect chromosomes 1 (p11, q21-qter), 11 and 16, although no common markers existed in all cases. Cytogenetics is the most sensitive technique, but the low yield (22 out of 140 tumors assayed) considerably restricts its value in any prospective breast cancer study.

[45,X/46, XYnf/47, XYnfYnf/46, X, dic (Ynf) (q12) mosaicism in a female patient with gonadal dysgenesis and the stigmata of Turner's syndrome]

A 17-year-old girl was referred to us because of primary amenorrhea and features of Turner's Syndrome. The karyotype obtained from peripheral lymphocytes cultures was mos 45,X/46, XYnf/47, XYnfYnf/46, X, dic (Ynf) (q12). The karyotype of fibroblasts derived from cultures of both gonads was mos 45, X/46, XYnf/47, XYnfYnf. The Y chromosome was non-fluorescent in all the examined lines. We report here the clinical and cytogenetic findings in a patient with an unusual sex chromosome mosaicism.

[2 new cases of Y-autosome translocation associated with azoospermia]

We present two new cases of Y-autosome translocation which were detected in two azoospermic males. In the first case the translocation was de novo with the karyotype: 46,XY,t(Y;16)(q12;q11-12). In the second case the karyotype was: 46,XY,t(Y;1)(cen-q11;cen-p11), t(Y;15)(q12;p11), the mother having been a carrier of the same Y-15 translocation, and showing the chromosomic formula: 46,XX,t(Y;15)(q12;p11).

An unusual translocation associated with recurrent spontaneous abortions

The authors report a case of 11;17 translocation associated with recurrent spontaneous abortions, and request contact with colleagues who have observed similar cases.

Congenital hyperthyroidism with reciprocal translocation t(1;17)(q25;q21)

The authors report a case of 1;17 translocation and request contact with colleagues who have observed similar cases.

Two new cases of primary peripheral neuroepithelioma of soft tissue with translocation t(11;22)(q24;q12)

A direct cytogenetic analysis was performed on tumor samples obtained from two patients with clinical and histopathologic diagnosis of primary peripheral neuroepithelioma. Both tumors presented the translocation t(11;22)(q24;q12). These results confirm those previously obtained by other authors and suggest a common histogenetic origin for this tumor with Ewing's sarcoma and Askin's tumor, in which the same translocation has been described.

An azoospermic male with reciprocal translocation t(1;15) (q11;p11)

The authors report on a case of 1;15 translocation and request contact with any colleagues who have observed similar cases.