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W Böcker

Publications and source records attributed to W Böcker.

232 records · Page 13Linked to original sources
PubMed1975

[Cardiac glomus tumor. Light- and electron microscopic investigations (author's transl)].

A cardiac glomus tumor, first described by Masson, was observed in a 28 year old woman who presented symptoms of cardiac dysfunction. Electron microscopic studies disclose a wide range of differentiation of glomus cells from smooth muscle cells to epitheloid cells. The common feature of both cell types include cytoplasmic microfibrils, fusiform condensations and small vesicles. The endothelial cells also show some structural similarities to these glomus cells. The histogenesis of this cardiac tumor is discussed on the basis of its ultrastructure and its uncommon localization. It is concluded that cardiac glomus tumors arise from primitive mesenchymal cells.

Adult↗
PubMed1975

Electron microscopy of uterine leimyosarcomas.

Electron microscopic studies of uterine leiomyosarcoma disclose a wide range of differentiation in the neoplastic cells. According to the cytoplasmic appearance undifferentiated, myoblastic, and fibroblast-like cells can be distinguished. Derivation of these cells from mesenchymal cells or poorly developed smooth muscle cells of the myometrium is suggested by the finding of numerous variously differentiated intermediate cell types. The cytoplasm of more differentiated tumour cells usually contains myofilament bundles. Three types of filaments are detected: small, intermediate and thick ones. While the thin ones probably are actin filaments, the intermediate and thick filaments are suggested to represent nonspecific filaments described in a variety of other cell types. Fibroblastic cell types are more often encountered and are usually better differentiated in the premenopausal woman. The possible role of endogenous hormonal factors on the differentiation process of tumour cells is discussed.

Age Factors↗
PubMed1975

Mixed Müllerian tumors of the uterus. Ultrastructural studies on the differentiation of rhabdomyoblasts.

In the present study the differentiation of rhabdomyoblasts of two carcinosarcomas of the uterus is analysed electronmicroscopically. During the development of rhabdomyoblasts three cell types can be distinguished: 1. the undifferentiated mesenchymal cell with abundant ribosomes but few other cell organelles. Usually these cells are already associated to each other in strands of 2-4 cells. Occasionally cytoplasmic areas with numerous nonspecific filaments can be observed. 2. the light rhabdomyoblast which is characterized by its conspicuous nonspecific cytoplasmic filaments and its reduction in ribosomes. Specific myofilaments can be visualized only occasionally in this cell type. 3. more differentiated rhabdomyoblasts. These cells can be identified clearly by the presence of large numbers of myofibrils and myofibrillar fragments. Higly organized myofibrils as seen in skeletal muscle are seldom found. Transitional forms between these cell types are also observed. The functions of Z-bodies and of the sarcotubular system in the process of myofibrillar differentiation are discussed.

Aged↗
PubMedDate not supplied

Assessment of molecular genetic detection of chromosome translocations in the differential diagnosis of pediatric sarcomas.

BACKGROUND: Recent studies have shown that many types of soft-tissue sarcomas are characterized by specific chromosomal translocations, which are likely to be of etiologic significance. In order to evaluate their diagnostic impact, a panel of 129 sarcomas comprising 78 Ewing's tumors (ET), 19 rhabdomyosarcomas (RMS), 20 neuroblastomas (NB), 9 synovialsarcomas, 2 esthesioneuroblastomas, and 1 desmoplastic small-round-cell tumor (DSRCT) were analysed for the occurrence of the major recurrent translocations, such as t(11;22)(q24;q12), t(21;22)(q22;q12), t(11;22)(p13;q12), t(2;13)(q35;q14), t(1;13)(p36;q14), and t(X;18)(p11;q11). METHODS: Nitrogen-frozen tissue material was analysed by means of Reverse Transcription followed by PCR (Polymerase-Chain Reaction) and nested PCR (RT-PCR). Specificity of the PCR products obtained was confirmed by non-isotopic Southern-Blot analysis with gene-specific probes and/or automated direct sequence analysis. RESULTS: 75 ETs have been shown to carry either a t(11;22) or t(21;22) translocation by identification of chimeric EWS-FLI-1 or EWS-ERG gene-fusion transcripts respectively. 3 ETs were lacking EWS/FLI-1 or EWS-ERG fusion products. 2 of these tumors were shown on review to have unusual morphological features for ETs. 8/19 RMS were initially diagnosed as alveolar RMS. These tumours were shown to carry either a t(2;13) translocation exhibiting chimeric PAX3-FKHR fusion transcripts or a t(1;13) translocation with PAX7-FKHR chimeric gene products. One RMS of the embryonal group also carried a t(1;13) translocation. Reevaluation demonstrated a partly alveolar morphology. In 8/9 synovial sarcomas a t(X;18) translocation was identified. Expression of a EWS-WTI gene-fusion product associated with a t(11;22) translocation was found in the DSRCT. None of these rearrangements were detected in the NBs and 2 esthesioneuroblastomas. CONCLUSIONS: Our results support the concept that the major recurrent translocations are histogenetically specific for a subset of sarcomas. Thus, the detection of tumor type-specific translocations represents an extremely useful diagnostic modality as an adjunct to surgical pathology.

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