Translocation (13;22) in a hemangiopericytoma

Pediatric orbital hemangiopericytoma associated with trisomy 15

We report a case of an orbital hemangiopericytoma (HPC) in a female infant diagnosed at 7 weeks of age. Cytogenetic analysis of the tumor revealed trisomy 15. To the authors' knowledge, this is only the second reported case of this chromosomal aberration being associated with HPC, both cases occurring in infants.

Low-grade sarcomas with CD34-positive fibroblasts and low-grade myofibroblastic sarcomas

A subset of low-grade fibrosarcomas is composed of CD34-positive spindle cells. These include dermatofibrosarcoma, its morphologic variants, and its associated fibrosarcoma, solitary fibrous tumor, hemangiopericytoma and their malignant counterparts, and some cases of myxoinflammatory fibroblastic sarcoma. Dermatofibrosarcoma and related lesions are characterized by a t(17;22)(q22;q13) rearrangement resulting in fusion of the genes COL1A (17q21-22) and PDGFB1 (22q13). Solitary fibrous tumor displays varying cellularity and fibrosis and a peripheral hemangiopericytomatous pattern; most tumors formerly called hemangiopericytoma are now subsumed into the category of solitary fibrous tumor, although a few strictly defined examples are recognized; however, these are probably not composed of pericytes. Myofibroblastic malignancies are best identified by electron microscopy, with which varying degrees of differentiation, including the presence of fibronexus junctions, can be identified. Low-grade sarcomas showing myofibroblastic differentiation include myofibrosarcomas and inflammatory myofibroblastic tumors. Myofibrosarcomas are spindle cell neoplasms that occur in children or adults in the head and neck, trunk, and extremities as infiltrative neoplasms and that display a fascicular or fasciitis-like pattern with focal nuclear atypia and variable expression of myoid antigens. These sarcomas are prone to recurrence and a small number metastasize. Inflammatory myofibroblastic tumor (synonymous with inflammatory fibrosarcoma) is a neoplasm arising predominantly in childhood, and frequently in intraabdominal locations. It has spindle cells in fascicular, fasciitis-like and sclerosing patterns, with heavy chronic inflammation including abundant plasma cells. Many IMT have clonal chromosomal abnormalities involving 2p22-24, and fusion of the ALK gene with tropomyosin 3 (TPM3-ALK) or tropomyosin 4 (TPM4-ALK) is found in a subset.

Pediatric soft tissue sarcomas

Many of the soft tissue sarcomas that occur in children are of the same histology as those in adults; however, the relative prevalence of these sarcomas is different between children and adults. In some cases, the biologic behavior of pediatric sarcomas is more benign than that in adults. Treatment for sarcomas in children is also different. Pediatric sarcomas are more commonly responsive to chemotherapy. Furthermore, in children who are still growing, surgery and radiation are associated with higher morbidity than in adults. This article discusses the diagnosis and treatment of rhabdomyosarcoma and undifferentiated sarcomas, with an emphasis on surgical considerations, and the diagnosis and treatment of nonrhabdomyosarcomatous soft tissue sarcomas in children.

Trisomy 15 in a case of pediatric hemangiopericytoma and review of the literature

This study reports on a pediatric case of hemangiopericytoma (HPC) showing trisomy 15 as a sole anomaly. Trisomy 15 was observed in a total of 11 cells harvested at a very early passage from two different in-situ cultures. Trisomy 15, as a sole anomaly, has been described in hematologic disorders such as myelodysplastic syndromes but, to our knowledge, has never been documented in solid tumors. This is the first report of HPC with trisomy 15.

Chromosomal imbalances in meningeal solitary fibrous tumors

We present the results of a comparative genomic hybridization (CGH) analysis of three meningeal solitary fibrous tumors (SFT). One case showed loss of chromosome 3 and two tumors had deletions of the region 3p21-p26. Other chromosomal losses included 4p15, 8q22-q24, 10, 11q14-q25, 17q11- q23, 20, and 21 in one case each. In addition, there were gains of 18p11-p13 in one case, and 1p11-p36 and 20q11-q13 in another. To our knowledge, there are no previous CGH or cytogenetic data on meningeal SFT, and loss of material on chromosome 3 has not been described in SFT at other sites. Our findings are discussed in relation to published molecular genetic and cytogenetic data on meningioma and hemangiopericytoma, the two lesions with which meningeal SFT are most likely to be confused.

Molecular cytogenetic study of a hemangiopericytoma in a newborn

Two balanced reciprocal chromosome translocations, t(8;12)(p21;p13. 1) and t(15;16)(q24;q22), characterized a rare hemangiopericytoma in a newborn. Chromosome painting with a chromosome microdissection-derived whole-chromosome 8 probe confirmed that the t(8;12) was due to a reciprocal translocation. To the best of our knowledge, these chromosome findings are unique to this unusual case of a pediatric hemangiopericytoma.

Cytogenetics of tumors of soft tissue and bone. Implication for pathology

Pathologists should be aware of the existence of diagnostically useful chromosomal rearrangements in several soft tissue and bone tumors. They include rearrangement of 8q12 in lipoblastomas, ring chromosomes in atypical lipomas, ring and giant marker chromosomes in well differentiated liposarcomas, t(12;16)(q13;p11) in myxoid liposarcomas, rearrangement of 7p21-22 in low-grade endometrial stromal sarcomas, t(2;13)(q37;q14) in alveolar rhabdomyosarcomas, t(X;18)(p11.2;q11.2) in synovial sarcomas, t(12;22) (q13;q13) in clear cell sarcomas, t(11;22)(q24;q12) in Ewing's sarcomas and peripheral neuroepitheliomas, and t(9;22)(q21-31;q11-12) in extraskeletal myxoid chondrosarcomas.

Cytogenetic studies of four hemangiopericytomas

We report cytogenetic studies on four hemangiopericytomas using in situ culture and robotic harvesting. Simple clonal chromosome abnormalities were observed in each of the three successful tumors. A cerebral tumor had a nonconstitutional 46,XX,t(7;12)(p15;q15) karyotype. A recurrent cerebral tumor had two cell lines: one with a 46,XY,t(2;12)(p13;q24.1) karyotype and one with a 46,XY,t(5;7)(q13;p15) karyotype. Each of the metaphases from a lung tumor had a 46,Y,inv(X)(p22.3q13) karyotype. We conclude that simple nonconstitutional balanced chromosome anomalies of 7p15 and 12q are common in cerebral hemangiopericytomas. It is possible that balanced anomalies of these chromosome regions are related to the pathogenesis of this tumor type.

Analysis of chromosome 22 loci in meningioma. Alterations in the leukemia inhibitory factor (LIF) locus

Meningiomas are typically benign tumors arising from arachnoidal cells at the base of the brain. Meningioma is thought to result from the loss or inactivation of a putative tumor suppressor gene located on chromosome 22. We analyzed a set of meningioma DNA specimens by Southern blot hybridization with chromosome 22-specific probes and by PCR using oligomer primers and probes specific to the leukemia inhibitory factor (LIF) gene. Southern analysis suggested that a subset of our specimens are monosomic for 22q11-qter and may have lost one entire copy of chromosome 22. The gene(s) involved in the etiology of meningioma has been localized to 22q11.2-12.3. The locus encoding LIF, a factor that affects the differentiation and proliferation of numerous cell types, has also been localized to this region, at 22q12.1-12.2. The partial overlap of these loci, coupled with the known involvement of the LIF gene product in growth and differentiation, suggested that the LIF locus may be associated with the meningioma defect. We have examined the LIF locus in meningioma specimens at the molecular level by PCR, and by DNA and RNA gel-blot hybridizations. Alterations in the structure and/or expression of the LIF locus were detected in several specimens, including the subset that were shown to be monosomic for 22q. All of our tumor specimens were shown to be undermethylated at the LIF locus relative to constitutional DNA from the same patients. Sequence analysis of LIF cDNA from a meningioma revealed the existence of a novel, alternatively spliced LIF mRNA. These results suggest that the LIF gene may be near the putative tumor suppressor locus associated with the development of this phenotype.

Cytogenetics of cranial base tumors

Many different tumor types can arise in or invade the skull base. The more common tumors include, but are not limited to, angiofibromas, chondrosarcomas, chordomas, hemangiopericytomas, meningiomas, carcinomas, olfactory neuroblastomas, paragangliomas, pituitary adenomas, and rhabdomyosarcomas. Several of these tumors, including meningiomas, hemangiopericytomas, and rhabdomyosarcomas are characterized by nonrandom cytogenetic abnormalities. In this paper, we review the recognized chromosomal aberrations in cranial base tumors and illustrate the insights that can be gained into the genetic basis of tumor formation using karyotypes from skull base tumors that we have examined. As in tumors in other locations, chromosomal findings may be of diagnostic and prognostic value in cranial base tumors.

Recurrent t(12;19)(q13;q13.3) in intracranial and extracranial hemangiopericytoma

We report on a recurrent intracranial hemangiopericytoma cytogenetically studied after short-term culture. The tumor had a uniform karyotype 47,XX,add(7)(q21),t(12;19)(q13;q13.3),del(13)(q14q22), +21. Remarkably, one case with an identical reciprocal (12;19) translocation has been previously reported as the sole cytogenetic change in a recurrent retroperitoneal hemangiopericytoma. This nonrandom structural change may characterize a subentity of hemangiopericytoma and might be of diagnostic value.

Aberrations of chromosome segment 12q13-15 characterize a subgroup of hemangiopericytomas

BACKGROUND

In later years, several characteristic acquired chromosomal aberrations have been identified in mesenchymal tumors. Many of these aberrations, either alone or with histopathologic and clinical data, are useful in diagnosis. The cytogenetic profile of hemangiopericytomas has been poorly investigated.

METHODS

Short-term cultures from four spindle cell tumors were cytogenetically analyzed.

RESULTS

Clonal acquired chromosome aberrations were found in three of the four tumors: inv(12) (q14q24) in a malignant hemangiopericytoma, a supernumerary der(3)t(3;12) (p21-23;q13-15) in a benign hemangiopericytoma, and t(6;12;19) (p21;q13;p13) in a spindle cell sarcoma that was histologically a malignant hemangiopericytoma or a synovial sarcoma. The fourth tumor, a malignant hemangiopericytoma, had a normal karyotype. The tumors with inv(12) and t(6;12;19) had subclones with trisomy 5 in addition to the structural changes.

CONCLUSIONS

The current findings and the literature data indicate that a subgroup of hemangiopericytomas is characterized by rearrangement of chromosome segment 12q13-15.

t(12;22)(q13;q13) and trisomy 8 are nonrandom aberrations in clear-cell sarcoma

We report a case of clear-cell sarcoma with a t(12;22)(q13;q13) and multiple copies of chromosome 8 in addition to other abnormalities. An identical or similar translocation has previously been reported in this type of tumor, suggesting that the t(12;22) is a primary cytogenetic change in the pathogenesis of a subset of clear-cell sarcomas. In addition, the presence of extra copies of chromosome 8, commonly noted in our case and others, suggests that it represents a nonrandom secondary change in these tumors.

Morphological and cytogenetic studies of angiosarcoma in Stewart-Treves syndrome

A morphological and cytogenetic analysis of a multifocal angiosarcoma in a typical case of Stewart-Treves syndrome is reported. The morphological analysis indicated differentiation along both blood and lymph vessel endothelium lines. By light and electron microscopy there were areas with well-developed erythrocyte-containing, capillary-like vessels and poorly differentiated areas with abortive vascular formations. In these the endothelium revealed immunoreactivity to factor VIII RAg, binding of Ulex europaeus I and Psophocarpus tetragonolobus agglutinin lectins, Weibel-Palade bodies ultrastructurally and presented a continuous enclosing external lamina and immunoreactivity for laminin and collagen IV, all features of blood-vessel differentiation. There were also lymphangioma-like areas as well as poorly differentiated areas where the immunohistochemical, lectin-binding and ultrastructural features were compatible with a lymph vessel differentiation. Cytogenetic analysis of cultured tumour cells revealed chromosome counts in the diploid region. About 40% of the cells analysed had a normal diploid karyotype. The remaining cells showed a multitude of mainly nonclonal structural alterations; 17 unique marker types resulting from different translocations and deletions were observed. There were also a few cells with clonal numerical deviations showing monosomy 22, monosomy X and trisomy 2 respectively. It is of interest that the losses of chromosome 22 and the X chromosome also have been observed in Kaposi's sarcoma and that the PD-ECGF gene, a novel angiogenetic factor, has been mapped to chromosome 22.

Clonal chromosomal abnormalities in hemangiopericytoma

We report the cytogenetic findings in nine hemangiopericytomas studied after short-term culture. Clonal chromosome abnormalities were present in four cases. One case had a simple translocation (12;19)(q13;q13.3) as the sole abnormality whereas complex and multiple chromosomal abnormalities involving almost all chromosomes in the complement characterized tumors from the three other cases.

Organization and chromosomal localization of the human platelet-derived endothelial cell growth factor gene

Human platelet-derived endothelial cell growth factor (hPD-ECGF) is a novel angiogenic factor which stimulates endothelial cell growth in vitro and promotes angiogenesis in vivo. We report here the cloning and sequencing of the gene for hPD-ECGF and its flanking regions. This gene is composed of 10 exons dispersed over a 4.3-kb region. Its promoter lacks a TATA box and a CCAAT box, structures characteristic of eukaryotic promoters. Instead, six copies of potential Sp1-binding sites (GGGCGG or CCGCCC) were clustered just upstream of the transcription start sites. Southern blot analysis using genomic DNAs from several vertebrates suggested that the gene for PD-ECGF is conserved phylogenetically among vertebrates. The gene for hPD-ECGF was localized to chromosome 22 by analysis of a panel of human-rodent somatic cell hybrid lines.

Organization and chromosomal localization of the human platelet-derived endothelial cell growth factor gene

Human platelet-derived endothelial cell growth factor (hPD-ECGF) is a novel angiogenic factor which stimulates endothelial cell growth in vitro and promotes angiogenesis in vivo. We report here the cloning and sequencing of the gene for hPD-ECGF and its flanking regions. This gene is composed of 10 exons dispersed over a 4.3-kb region. Its promoter lacks a TATA box and a CCAAT box, structures characteristic of eukaryotic promoters. Instead, six copies of potential Sp1-binding sites (GGGCGG or CCGCCC) were clustered just upstream of the transcription start sites. Southern blot analysis using genomic DNAs from several vertebrates suggested that the gene for PD-ECGF is conserved phylogenetically among vertebrates. The gene for hPD-ECGF was localized to chromosome 22 by analysis of a panel of human-rodent somatic cell hybrid lines.

Cytogenetic findings in clear cell sarcoma of tendons and aponeuroses. Malignant melanoma of soft parts

Cytogenetic analyses of clear cell sarcomas from two patients are reported. Clonal numerical and structural abnormalities were detected in both specimens, with specific involvement of chromosomes 2 and 22 in each.

Regional localization and molecular characterization of a DNA sequence on the long arm of chromosome 22

A human genomic DNA fragment, p22hom13 (D22S16), was isolated from a chromosome 22-specific library. After elimination of repetitive sequences, a single copy BamHI-EcoRI fragment was subcloned into pTZ18. By using mouse/human somatic cell hybrids and in situ hybridization, the new DNA probe was mapped to chromosome 22q13-qter. Its application in the analysis of the distal part of chromosome 22 and its diagnostic use in translocations are discussed.

Cytogenetic findings in malignant fibrous histiocytoma

The cytogenetic findings of two malignant fibrous histiocytomas from two unrelated patients are discussed. Both tumors were characterized by trisomy 7.