1/7. Cutaneous sclerosing Pacinian-like perineurioma.AIMS: The term perineurioma has been used to designate a variety of clinically and histologically different proliferations of perineurial cells based on immunohistochemical and/or ultrastructural characterization. There are two different groups of neoplasms derived from perineurial cells: extraneural or soft tissue perineuriomas, and intraneural perineuriomas. Recently, a sclerosing variant of cutaneous perineurioma has been described. methods AND RESULTS: We report a case of a cutaneous form of perineurioma, combining features of the intraneural and sclerosing varieties, as well as showing a Pacinian pattern of growth. In order to assess the neoplastic nature of the lesion, we performed fluorescence in-situ hybridization (FISH) analysis using a probe which maps to the chromosome band 22q11 and 22q13, allowing us to show deletion or loss of one chromosome 22 in the tumour cells. CONCLUSIONS: This case may be considered a new variant of perineurioma with Pacinian-like features, for which we propose the designation 'sclerosing Pacinian-like perineurioma'.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/7. Evidence for involvement of a tumor suppressor gene on 1p in malignant peripheral nerve sheath tumors.Malignant peripheral nerve sheath tumors (MPNST) are rare soft-tissue malignancies. The genetic basis of these tumors is still poorly understood. Cytogenetic analyses predominantly revealed complex karyotypes, precluding the identification of recurrent chromosomal changes. We report loss of 1p material in a near-diploid karyotype with few or no additional structural chromosome changes in two sporadic cases of MPNST, indicating an important role of 1p loss in MPNST development. In one of these two tumors, a distal 1p deletion (1p31.2 approximately pter) was detected suggesting involvement of a tumor suppressor gene located within this distal region of 1p. Further evidence for recurrent 1p loss in MPNST was obtained by interphase fluorescence in situ hybridization, which showed loss of 1p material in 3 out of 13 tumors. These findings together with data from the literature suggest that loss of a tumor suppressor gene located within distal 1p is implicated in the pathogenesis of MPNST.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/7. Cytogenetic study of malignant triton tumor: a case report.Malignant triton tumor (MTT) is a highly malignant neoplasm, classified as a variant of malignant peripheral nerve sheath tumor (MPNST) with rhabdomyoblastic differentiation. Few cytogenetic studies of MTT have been reported using conventional cytogenetic analysis. Here, we report a comprehensive cytogenetic study of a case of MTT using G-banding, spectral karyotyping(), and fluorescence in situ hybridization (FISH) for specific regions. A complex hyperdiploid karyotype with multiple unbalanced translocations was observed: 48 approximately 55,XY,der(7)add(7)(p?)dup(7)[2],der(7) t(7;20)(p22;?)ins(20;19)[5],der(7)ins(8;7)(?;p22q36)t(3;8)t(8;20)[15],-8[5],-8[19 ],r(8)dup(8), der(8)r(8;22)[4],-9[9],der(11)t(11;20)(p15;?)ins(20;19)[22],der(12)t(8;12)(q21;p 13)[21],der(13) t(3;13)(q25;p11),-17,-19,der(19)t(17;19)(q11.2;q13.1),-20,-22, 4 approximately 7r[cp24]/46,XY[13]. The 1995 International System for Human Cytogenetic Nomenclature was followed where possible. Note that breakpoints were frequently omitted where only SKY information was known for a small part of an involved chromosome. Our analysis revealed some breakpoints in common with those previously reported in MTT, MPNST, and rhabdomyosarcoma, namely 7p22, 7q36, 11p15, 12p13, 13p11.2, 17q11.2, and 19q13.1. FISH showed high increase of copy number for MYC and loss of a single copy for TP53.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/7. Differential diagnosis of non-epithelial tumors of the pancreas: malignant non-epithelial pancreatic tumor with focal pigmentation.Non-epithelial tumors only rarely affect the pancreas. In this report, we describe a malignant non-epithelial tumor with combined characteristics of malignant peripheral nerve sheath tumor (MPNST) and malignant melanoma. To more closely define the differential diagnosis of MPNST with focal pigmentation versus metastatic melanoma resembling MPNST, the tumor was investigated using histomorphology, immunohistochemistry, electron microscopy, and comparative genomic hybridization. As a result, from these analyses and from clinical findings, the diagnosis of a pancreatic MPNST with focal pigmentation was favored. However, the diagnosis of a malignant melanoma or a composite tumor could not be definitely ruled out, due to the considerable morphological and genotypical overlap between both entities, which can be explained by the close histogenetic relationship between both tumor entities.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/7. Loss of chromosome 13 in a case of soft tissue perineurioma.Soft tissue perineuriomas are rare mesenchymal tumors that are derived from perineurial cells of the peripheral nerve sheath. Although the histological and immunohistochemical features of soft tissue perineuriomas are well described, little is known regarding the cytogenetic abnormalities in these tumors. Herein, we describe a case of a large (12.2 cm) soft tissue perineurioma that arose in the thigh of a 26-year-old Caucasian female. Histologically, the tumor was composed of a diffuse to fascicular arrangement of spindle cells with bland, elongated nuclei with long, thin, tapering cytoplasmic processes. The immunohistochemical profile was consistent with a perineurial cell origin with expression of epithelial membrane antigen, vimentin, and collagen type iv. Cytogenetic evaluation revealed loss of chromosome 13 as the sole abnormality in the majority of examined cells. In contrast to previous reports, we were unable to demonstrate deletion or structural abnormalities of chromosome 22 by either fluorescence in situ hybridization (FISH) or metaphase cytogenetics. This is the first report of loss of chromosome 13 in soft tissue perineurioma. Although never described in this group of neoplasms, loss of chromosome 13 has been identified in a large number of other soft tissue tumors, particularly sarcomas and malignant peripheral nerve sheath tumors. Herein, we discuss this case and provide a review of the literature.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/7. A cytogenetic analysis in two cases of malignant peripheral nerve sheath tumor showing hypodiploid karyotype.In this study, we report cytogenetic findings in two cases of malignant peripheral nerve sheath tumor (MPNST) with hypodiploid karyotypes. A G-band technique, multicolor fluorescence in situ hybridization (m-FISH) and comparative genomic hybridization (CGH) were used and compared in this investigation. In both tumors, the G-band and m-FISH analysis demonstrated multiple rearrangements on chromosomes 1-5, 8-12, 15-17, 20 and 21, whereas CGH exhibited gains at 8q and 4q. Both of the structural aberrations and the genomic imbalances of the chromosomes may play an important role in the pathogenesis and development of MPNST. No cytogenetic abnormalities specific for MPNST were found in the present cases or in other previously reported cases. This may reflect the diversity or heterogeneity of MPNST that exhibit various clinical and histological features. However, there are few cases described in detail on a morphologic pattern of MPNST, a correlation between the cytogenetic aberrations and the histologic patterns are still uncertain.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
7/7. Soft-tissue perineurioma. Evidence for an abnormality of chromosome 22, criteria for diagnosis, and review of the literature.Reported herein are two examples of soft-tissue perineurioma (STP), one arising in the maxillary sinus and the other in subcutaneous tissue of the thigh. Electron microscopy and immunohistochemistry were performed in both cases. Based on our findings and a critical review of the literature, STPs are generally small, well-circumscribed but not encapsulated tumors. Histologically, most STPs resemble fibroblastic tumors, being composed of elongated, wavy cells. The immunohistochemical reactivity for epithelial membrane antigen, the lack of reactivity for S-100 protein, and the presence of ultrastructural features of perineurial cells are typical of this tumor. To explore the possibility that STP, like the intraneural variety of perineurioma, exhibits an abnormality of chromosome 22, we performed fluorescence in situ hybridization with a probe specific for the M-bcr locus, which maps to the chromosome band 22q11. In both our tumors, a high percentage of nuclei having only one M-bcr signal (44 and 96%) was observed. Our findings indicated deletion of part or all of chromosome 22 and support the view that both soft-tissue and intraneural perineurioma are part of a spectrum of perineurial neoplasia.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |