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I De Wever

Publications and source records attributed to I De Wever.

At least 55 records · Page 3Linked to original sources
PubMed1996

Combined morphologic and karyotypic study of 28 myxoid liposarcomas. Implications for a revised morphologic typing, (a report from the CHAMP Group).

Cytogenetic analysis carried out in 28 adipose tissue tumors diagnosed microscopically as myxoid liposarcoma (ML) revealed a t(12;16)(q13:p11) chromosomal translocation in 26 of the 28 cases. Morphologically, these tumors were subclassified into the following categories: well-differentiated, six cases: poorly differentiated round cell type, 17 cases: poorly differentiated spindle cell type, five cases. Poorly differentiated ML behaved in a more aggressive fashion than the well-differentiated tumors. The results of this study confirm the consistency and specificity of the t(12;16)(q13:p11) translocation as the genetic marker of ML, support the contention that liposarcomas with round cells belong to the ML category, and confirm Stout's proposal for the existence of a poorly differentiated ML composed of spindle cells. Cytogenetic analysis may be helpful in the differential diagnosis of ML with atypical lipomatous tumors, which is characteristically associated with ring and giant marker chromosomes, and of ML with lipoblastoma, which is typically associated with 8q alterations. The existence of a mixed ML-atypical lipomatous tumor remains questionable. The genetic events associated with the greater aggressiveness of the poorly differentiated types of ML remain to be determined.

Adult↗
PubMed1996

CD40 is a prognostic marker in primary cutaneous malignant melanoma.

CD40 is a receptor at the surface of B lymphocytes with important functions in the immune response. CD40 has also been found on a variety of carcinoma and melanoma cell lines where it has been suggested to serve as a possible receptor for mitogenic signals. We studied the expression and distribution of CD40 in paraffin sections of 71 uniformly treated malignant melanomas (MMs) with a long clinical follow-up using well known monoclonal antibodies. For comparison, 71 benign nevi were also studied. Common acquired nevi occasionally expressed CD40 in nests or single cells at the dermo-epidermal junction; no immunoreactivity was observed in the dermal part of acquired nevi, and all Spitz' nevi were entirely negative. One-third of large congenital nevi expressed CD40 in small clusters of heavily pigmented, epithelioid cells, corresponding to so-called proliferative nodules. In 41 of 71 MMs, CD40 was expressed in single or clustered neoplastic melanocytes; 9 cases showed CD40 expression only in the radial growth phase, and in 32 cases, the vertical growth phase showed CD40 expression. The same staining pattern was obtained with other anti-CD40 monoclonal antibodies, directed to different epitopes of the CD40 molecule. In 29 of 32 MMs showing CD40 in the vertical growth phase, expression of the CD40 ligand (CD40L) was studied; in 13 of these 29, CD40L was found in the same tumor areas that expressed CD40. Analysis of 28 metastases from 24 MM patients showed in the majority of cases a similar, scattered or nodular staining pattern as observed in the primary tumor. Patients expressing CD40 in the vertical growth phase of their MM did not differ significantly from CD40-negative patients with respect to any of the known prognostic parameters but showed a significantly shorter tumor-free survival. Patients with CD40+ CD40L+ MM tended to have a shorter tumor-free survival than those lacking CD40L. We conclude that CD40 represents a novel prognostic parameter in primary cutaneous MM. The co-localization of CD40 and CD40L suggests an autocrine growth loop in the vertical growth phase of MM.

Biomarkers, Tumor↗
PubMed1995

Monosomy 22 in a malignant peripheral nerve sheath tumour of the kidney in childhood: a genetic link with other malignant paediatric renal neoplasms?

A recurrent malignant spindle cell neoplasm of the kidney, occurring in a 11-year-old girl and corresponding to a malignant peripheral nerve sheath tumour is reported. The neurogenic differentiation was substantiated by the presence of PGP 9.5 neurofilament and S-100 protein positivity and by the ultrastructural features. Cytogenetic analysis revealed monosomy of chromosome 22 in the tumour while the constitutional karyotype was normal. Primary malignant peripheral nerve sheath tumour of the kidney is extremely rare and should, on morphology, be differentiated from stromal predominant Wilms' tumour and clear cell sarcoma of kidney. Involvement of chromosome 22 has been described in a number of malignant renal tumours of childhood, such as Wilms' tumour (deletion), clear cell sarcoma (translocation), and rhabdoid tumour (deletion and translocation), thus suggesting common molecular mechanisms in pediatric malignant renal tumours.

Child↗
PubMed1994

Cytogenetic characterization of tenosynovial giant cell tumors (nodular tenosynovitis).

Chromosome investigation in six localized forms of tenosynovial giant cell tumors, also known as modular tenosynovitis, revealed an identical translocation between chromosomes 1 and 2, t(1;2)(p11;q35-36) in three tumors, a variant translocation t(1;5)(p11;q22) in a fourth case, and a t(2;16)(q33;q24) in a fifth case. One case showed a normal karyotype. Although morphologically rather uniform, these benign tumors appear to be cytogenetically heterogeneous, but the chromosome changes seem to cluster in 2 regions, 1p11 and 16q24.

Adult↗
PubMed1994

Some desmoid tumors are characterized by trisomy 8.

Ten desmoid tumors were examined by chromosome banding analysis and by in situ hybridization on short-term cultures and frozen sections. Trisomy 8 was detected in four out of ten tumors, of which only one had shown trisomy 8 by karyotype analysis. Since trisomy 8 has been reported in superficial fibromatoses, which are clinically distinct but histologically similar to desmoid tumors, the occurrence of trisomy 8 in both may be a further indication of a close relationship.

Adolescent↗
PubMed1994

New discriminative chromosomal marker in adipose tissue tumors. The chromosome 8q11-q13 region in lipoblastoma.

Specific chromosome abnormalities characterize benign and malignant adipose tissue tumors and are of great diagnostic and clinical importance. Lipoblastoma is a rare benign adipose tumor that mimics myxoid liposarcoma histologically. Although only a few lipoblastomas have been investigated cytogenetically, it is increasingly clear that these adipose tissue tumor generally show rearrangements of 8q11-q13 region but lack the t(12;16) that allows these tumors to be distinguished from myxoid liposarcomas.

Chromosomes, Human, Pair 8↗
PubMed1994

Pleuropulmonary blastoma (pulmonary blastoma of childhood): genetic link with other embryonal malignancies?

A case of pleuropulmonary blastoma (childhood variant of pulmonary blastoma) was examined using histological, immunohistochemical, ultrastructural and cytogenetic methods. The tumour consisted of undifferentiated 'blastematous' areas admixed with zones of rhabdomyoblastic and chondroid differentiation and fascicular areas. Desmin and S-100 protein immunoreactivity confirmed the myogenic and cartilaginous differentiation. Ultrastructurally only undifferentiated mesenchymal cells were present. The cytogenetic analysis revealed abnormalities of 2q. Involvement of 2q has also been described in hepatoblastoma and embryonal rhabdomyosarcoma. Although further confirmation is needed, our cytogenetic findings in pleuropulmonary blastoma suggest common genetic mechanisms in some paediatric embryonal malignancies.

Biopsy↗
PubMed1993

Cytogenetic and fluorescence in situ hybridization investigation of ring chromosomes characterizing a specific pathologic subgroup of adipose tissue tumors.

Cytogenetic analysis of 184 adipose tissue tumors, 175 lipomas, and nine liposarcomas (LPS) showed the presence of a ring chromosome and/or a long marker chromosome in 10 cases with common histologic features such as atypical stromal cells with or without lipoblasts. In five of the cases, this appeared to be the sole cytogenetic abnormality. Fluorescence in situ hybridization (FISH) analysis with a microclone library specific for chromosome region 12q13-q15 showed extensive staining of the ring and long marker chromosomes, indicating that genetic sequences of this particular region of chromosome 12 are present in these marker chromosomes, most likely in an amplified form.

Adipose Tissue↗
PubMed1993

Alveolar soft-part sarcoma: evidence for its myogenic origin and for the involvement of 17q25.

A typical case of alveolar soft-part sarcoma was examined using ultrastructural, immunohistochemical and cytogenetic methods. Immunohistochemical stains were performed on frozen sections and showed strong desmin expression with the three anti-desmin antibodies used. In addition, the tumour cells were weakly positive for vimentin and myosin. Neural markers were negative. Chromosomal analysis showed consistent involvement of 17q25--an abnormality which has been reported in another alveolar soft-part sarcoma. The histogenesis of alveolar soft-part sarcoma is still debatable but our findings support a myogenic origin. The finding of an apparently identical chromosomal abnormality in two of three thus far examined cases of alveolar soft-part sarcoma is of interest and must await further confirmation, but it may result in the identification of a chromosomal marker for this enigmatic tumour and thus pave the way for further molecular elucidation.

Adult↗
PubMed1992

Numerical chromosome aberrations in fibrothecoma.

Cytogenetic analysis on a 7-day-old culture of a fibrothecoma showed only numerical chromosome abnormalities: 57, XX, +4, +5, +6, +10, +12, +12, +14, +17, +18, +19, +20. The finding of an extra copy of chromosome 12 in mesenchymal tumors, mostly benign and originating from the female genital tract, may possibly point towards their common embryonic origin.

Adult↗
PubMed1991

Infantile fibrosarcoma.

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Antineoplastic Combined Chemotherapy Protocols↗