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Biomedical subjects

R Sciot

Publications and source records attributed to R Sciot.

At least 127 records · Page 7Linked to original sources
PubMed1997

The use of Vicryl Collagen as a dura substitute: a clinical review of 78 surgical cases.

We performed a retrospective review of 78 consecutive neurosurgical procedures using Vicryl Collagen, a resorbable mesh of polyglactin 910 coated with bovine collagen, for dural substitution. The complications we encountered were infrequent and mostly minor (5 cases of subcutaneous CSF collections, 2 cases of aseptic meningitis, 1 superficial wound infection), and not unusual for the surgical procedures studied. One patient, however, had a major infection, starting in the superficial tissues, and extending toward the brain. In this patient, the resorption of the dural substitute appeared to be the cause for the intracranial extension of the infection. Three patients were reoperated on for recurrent tumour after a longer interval. We found minimal adhesions and good fibrous incorporation of the Vicryl Collagen into the surrounding normal dura. We conclude that Vicryl Collagen is a valuable alternative to the patient's own fibrous tissues when dural substitution is necessary.

Adolescent↗
PubMed1997

Giant schwannoma of the lower leg.

Schwannomas are relatively common, benign, peripheral nerve sheath tumours. They usually range in size from 2 to 20 cm, but when localised in the lower legs the maximum length is less than 10 cm. The case reported here was a giant fusiform schwannoma of the left fibular nerve with a length of 25.5 cm. In contrast to the usual findings of giant schwannomas, no cystic, haemorrhagic or necrotic changes could be found by ultrasonography, computed tomography or magnetic resonance imaging. The combination of tumour size, location and radiological presentation is very unusual and, to our knowledge, has never been reported before in the literature.

Adolescent↗
PubMed1997

Involvement of chromosomes 6 and 11 in a soft tissue chondroma.

Cytogenetic analysis of a soft tissue chondroma revealed monosomy 6 and rearrangement of chromosome 11. Previously described 12q13-q15 involvement was not found. Aberrations of chromosomes 6 and 11, however, have been reported before in this type of benign cartilaginous tumor.

Adult↗
PubMed1997

Chromosome analysis in angiomyolipoma.

Cytogenetic data on angiomyolipomas are scarce. We report a series of 10 cases from nine patients without clinical history of tuberous sclerosis. We found chromosome abnormalities in two, and in both cases the chromosomal changes were only numerical ones, i.e., trisomy 7 and trisomy 8.

Adult↗
PubMed1997

Sensitive and reliable detection of genomic imbalances in human neuroblastomas using comparative genomic hybridisation analysis.

Deletions of the short arm of chromosome 1, extra copies of chromosome 17q and MYCN amplification are the most frequently encountered genetic changes in neuroblastomas. Standard techniques for detection of one or more of these genetic changes are karyotyping, FISH analysis and LOH analysis by Southern blot or PCR. Each of these techniques has its own particular limitations. More recently, comparative genomic hybridisation (CGH) was introduced for detection of genomic imbalances including deletions, duplications and gene amplification. We evaluated the sensitivity and reliability of CGH for detection of the most frequently encountered genetic changes in neuroblastoma. For this purpose a panel of well-characterised neuroblastoma cell lines as well as a series of 11 primary neuroblastomas was analysed. Our results show that CGH is a valuable tool for the genetic characterisation of neuroblastomas, both for the detection of frequently occurring genomic imbalances and for the identification of previously unnoticed genetic changes.

Child, Preschool↗
PubMed1997

Lesions of 13q may occur independently of deletion of 16q in spindle cell/pleomorphic lipomas.

AIMS: Very recent multidisciplinary investigations have allowed for the definition among lipomas of a clinical and histological subtype called spindle cell and/or pleomorphic lipoma, possibly associated with partial monosomy 16 and anomalies of chromosome 13. In order to get nearer to the underlying critical molecular changes further multidisciplinary pathological and genetic research is indicated, to identify which chromosome(s) anomalies are crucial in the development of these tumours. METHODS AND RESULTS: In an ongoing multidisciplinary study of lipomatous tumours, including clinical findings, morphology, histochemistry and cytogenetics, two instances were found of spindle cell lipoma with clonal chromosome changes. In both cases chromosome 13 was involved, whereas only one showed a partial monosomy 16. CONCLUSIONS: Partial monosomy 16 is a characteristic lesion in spindle cell lipoma, usually associated with anomalies of chromosome 13. The present report confirming a previous single observation indicates, however, that lesions of 13 may occur independently from lesions of 16, suggesting different underlying molecular lesions in these otherwise very similar lipomas.

Chromosome Deletion↗
PubMed1997

Cytogenetic analysis of subcutaneous angiolipoma: further evidence supporting its difference from ordinary pure lipomas: a report of the CHAMP Study Group.

Subcutaneous angiolipomas are benign soft-tissue lesions consisting of two mesenchymal elements (i.e., adipose tissue and blood vessels) and having distinct clinical features. They usually are multiple, with an obvious male predominance, and hereditary occurrence has been described. Twenty subcutaneous angiolipomas from 10 patients with typical clinical and morphologic features were reviewed. All lesions had a normal karyotype. This finding is in striking contrast with ordinary lipomas, spindle-cell and pleomorphic lipomas, lipoblastomas, and hibernomas, most of which have characteristic clonal chromosomal aberrations. The normal karyotype of subcutaneous angiolipoma as well as its distinct clinical and morphologic features suggest a different pathogenesis from pure lipomas.

Adult↗
PubMed1997

Polymorphous hemangioendothelioma: a report of two cases, one affecting extranodal soft tissues, and review of the literature.

Polymorphous hemangioendothelioma (PH) is a rare vascular neoplasm occurring in lymph nodes. It has been considered a borderline malignant tumor, mainly because of a local recurrence in one of the three cases described to date. This report adds two additional cases, one in which the tumor was extranodal. An extensive immunohistochemical study and thorough literature review were undertaken. The patients, a 55-year-old man and a 28-year-old man, both asymptomatic, presented with tumors involving a left pulmonary hilar lymph node (3 cm) and the soft tissues of the left paravertebral region (4 cm), respectively. The tumors were composed of an admixture of solid, primitive vascular and ectatic angiomatous components, with both elements formed by uniform, polygonal cells. In one case, the cells marked for CD31 and factor VIII, and the other case was positive for CD34. Neither case marked for epithelial membrane antigen and keratin. One tumor partially replaced a lymph node, and no nodal tissue was identified in the other. Of the three previously reported cases of nodal PH, one had recurring and metastatic behavior. PH is a rare, malignant vascular neoplasm that most frequently involves lymph nodes, but it can also affect extranodal locations.

Adult↗
PubMed1997

Neuromuscular choristoma (hamartoma) with smooth and striated muscle component: case report with immunohistochemical and ultrastructural analysis.

Benign peripheral nerve tumors with a mesenchymal component are rare and are represented principally by the neuromuscular choristoma. We describe an 11-month-old male infant who presented with a mass arising from the left brachial plexus. The lesion was bound firmly to the involved nerves and consisted histologically and ultrastructurally of bundles of well-differentiated smooth muscle cells intermingled with striated muscle fibers and unmyelinated nerve fibers. In the 13 previously published cases of neuromuscular choristoma, no smooth muscle component was observed. This unique peripheral nerve choristoma with not only striated but also smooth muscle closely resembled neuromuscular choristoma and was considered a variant of it.

Brachial Plexus↗
PubMed1997

Inflammatory myofibroblastic tumor of bone: report of two cases with evidence of clonal chromosomal changes.

Inflammatory myofibroblastic tumor (inflammatory pseudotumor) is a pseudosarcomatous lesion that is recognized with increasing frequency in various anatomic locations. However, this lesion has not been previously reported in bone. We report on two cases of inflammatory myofibroblastic tumor occurring in bone in young adults. Both tumors presented as slightly painful, osteolytic, and well-delineated lesions of the distal femur, with a hyperintense signal on T2-weighted magnetic resonance imaging. The patients had an uneventful recovery after curettage. The follow-up time was 11 months for both patients, and no recurrence was noted. On histologic examination, the lesions were characterized by collagen-rich and generally poorly cellular tissue containing spindled to plump (myo)fibroblast-like cells and a variable admixture of inflammatory cells. Focal calcifications and reactive bone formation were present. Clonal, albeit different, chromosomal changes were found in both cases (47,XY,-9,-12,add(21)(q21),+der(?)t(?;9)(?;q11), +mar,+r and 47, XY, +r/47, idem, add(12)(p13)). The present and other reported cytogenetic findings suggest that inflammatory myofibroblastic tumors could well be neoplastic.

Adult↗
PubMed1997

Expression of HMGI-C and HMGI(Y) in ordinary lipoma and atypical lipomatous tumors: immunohistochemical reactivity correlates with karyotypic alterations.

The high mobility group proteins (HMGs) are a class of low molecular weight, nonhistone, nuclear proteins that bind DNA and function as transcription cofactors. This class includes the HMGI family members HMGI-C and HMGI(Y). Both are not significantly expressed in differentiated adult tissues, including fat, but their expression is induced in proliferating and transformed cells. Their involvement in the development of lipomatous tumors has been recently demonstrated for HMGI-C, which is encoded by a gene located at 12q15, the chromosomal segment often rearranged in ordinary lipomas. The same chromosomal segment is consistently amplified in the ring and giant marker chromosomes of atypical lipomatous tumors (ALTs), a term used to designate tumors previously labeled as well differentiated liposarcomas or atypical lipomas. The involvement of HMGI(Y) is strongly suspected as the gene coding for HMGI(Y) is located at 6p21, a chromosomal segment rearranged in a subset of ordinary lipomas. HMGI-C or HMGI(Y) protein expression was analyzed immunohistochemically in a group of 39 well differentiated adipose neoplasms (19 lipomas and 20 ALTs) of known karyotype using polyclonal antibodies raised against a recombinant protein (HMGI-C) and against a synthetic peptide (HMGI(Y)). The results of this study demonstrate that HMGI proteins are commonly expressed in well differentiated adipose neoplasms. Seventeen of twenty ALTS (85.0%), all of which had ring or giant marker chromosomes with amplification of 12q13-15, strongly expressed HMGI-C. HMGI-C expression was detected in 7 of 11 ordinary lipomas (63.6%) with alterations at 12q14-15 and in one case with an abnormal karyotype that included double minute chromosomes. HMGI-C immunoreactivity correlates with 12q13-15 chromosomal alterations (P = 0.001). HMGI(Y) reactivity was demonstrated in only two ordinary lipomas: one with 6p21 rearrangement and one with normal karyotype. No significant HMGI(Y) expression was found in the ALT group. The finding of aberrant expression of HMGI proteins in well differentiated adipose neoplasms in association with 12q13-15 and 6p21 chromosomal changes supports the proposed pathogenetic role of this group of proteins in the development of adipose tissue tumors.

Adult↗
PubMed1997

Primary osteorhabdomyosarcoma (malignant mesenchymoma) of bone: a case report and review of the literature.

Primary malignant mesenchymoma of bone is a rare neoplasm consisting of two or more unrelated malignant mesenchymal components other than fibrosarcoma or malignant fibrous histiocytoma. The literature reports fewer than 15 cases, most of which were composed of osteosarcoma and liposarcoma. We report an exceedingly rare case of primary malignant mesenchymoma of bone composed of osteosarcoma and rhabdomyosarcoma (osteorhabdomyosarcoma), arising in the right proximal tibia of a 21-year-old woman. We review the literature and compare primary malignant mesenchymoma of bone with dedifferentiated chondrosarcoma and conventional intramedullary osteosarcoma.

Adult↗
PubMed1996

Duplication of chromosome segment 12q15-24 is associated with atypical lipomatous tumors: a report of the CHAMP collaborative study group. CHromosomes And MorPhology.

Ordinary lipomas are cytogenetically characterized by a variety of balanced rearrangements involving chromosome segment 12ql3-15, and atypical lipomatous tumors (ALT) by supernumerary ring chromosomes or giant markers known to contain amplified 12q sequences. In a series of 228 cytogenetically analyzed and histopathologically reexamined ordinary lipomas and ALT, 10 tumors showed unbalanced chromosome-12 aberrations. All 4 tumors with loss of segments from 12q were classified as ordinary lipomas, whereas 5 of the 6 tumors showing gain of 12q material were diagnosed as ALT. One or three extra copies of 12q15-q24 were present in all 5 ALT. We conclude that duplication of 12q sequences may be a sufficient level of amplification for development of the microscopic appearance that characterizes ALT.

Chromosome Aberrations↗
PubMed1996

The role of immunosuppression in the long-term survival of tracheal allografts.

OBJECTIVES: To assess the functional aspects of vascularized tracheal allograft transplant models and the long-term fate of these allografts. To examine the effects of cyclosporin A (CsA), 10 mg/kg per day, on the long-term survival of vascularized tracheal allografts and the presence and significance of host immune tolerance after cessation of immunosuppression. DESIGN: In a rabbit model, tracheal allografts were orthotopically transplanted after an initial period of heterotopic fascia revascularization. A full-thickness skin allograft from the same donor was used as an external monitor of the rejection process. Treatment with CsA was discontinued (group 2) or given intermittently (group 3) after an initial course of continuous CsA administration varying from 2 to 10 weeks. The first group received a continuous regimen of CsA for 10 weeks. MAIN OUTCOME MEASURES: Tracheal and skin allograft deterioration, microcirculation of tracheal transplant, mucociliary clearance, and histopathologic examination. RESULTS: Tracheal allografts under continuous immunosuppression with CsA, 10 mg/kg per day, showed no rejection and remained functional with preservation of mucociliary activity. After an initial course of CsA to achieve solid tracheal union, subsequent cessation and intermittent pulsing of the immunosuppressant were insufficient in maintaining indefinite graft survival. Chronic allograft rejection with simultaneous endothelial graft repopulation could be induced by intermittent pulsing of CsA, which led to prolonged allograft survival in some group 3 animals. CONCLUSION: Continuous immunosuppression is necessary to preserve an optimal morphological and functional condition of tracheal allografts.

Animals↗
PubMed1996

Juvenile fibrosarcoma of the temporal bone.

A case of juvenile fibrosarcoma arising from the head and neck region is described. This type of tumour should be considered as a separate entity different from the fibrosarcoma in adults because of the different clinical behaviour. The symptomatology, the radiographic features and the literature data are reviewed.

Child, Preschool↗
PubMed1996

The t(1;12)(p36;q13) in a renal oncocytoma.

A new chromosome rearrangement, t(1;12)(p36;q13), is added to the cytogenetic changes found in renal oncocytomas. The breakpoint in 12q is cytogenetically different from those of the MAR region, and molecularly HMGIC located in 12q15 on the basis of 3' RACE experiments does not seem to be directly involved.

Adenoma, Oxyphilic↗