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C Kuhnen

Publications and source records attributed to C Kuhnen.

At least 19 recordsLinked to original sources
PubMed2002

[Solitary plasmacytoma of the shoulder. Diagnosis and therapeutic methods].

5% of all multiple myelomas manifest as solitary plasmocytomas. The multiple myeloma is the most frequent malignant transformation of the haematopoetic system, with an incidence of 2:100,000 per year. 1% of all solitary plasmocytomas are found in the extremities, accounting for less than one case per year in Germany. In this article we present the case of a fifty year old patient with a solitary plasmocytoma of the shoulder region and discuss the diagnostic and therapeutic procedures involved.

Diagnosis, Differential↗
PubMed2002

[Retrogastral located gastrointestinal stromal tumor (GIST) as a sonographically detected rare incidental finding].

Gastrointestinal stromal tumors (GIST) represent compared to carcinomas a rare group of neoplasias of the gastro-intestinal tract of unclear dignity. We report the example of a patient suffering from a big retrogastral located gastrointestinal stromal tumor which had been detected as an incidental finding without previous complaints. Because origin and dignity of the process could not definitely be diagnosed, total resection (R0-resection) without systemic lymphadenectomy of the process measuring 11.5 cm x 11 cm x 7 cm was performed. Mitotic activity and tumor-size are regarded as predictive factors of potenzial malignancy of GISTs. In general tumors with low mitotic activity of up to 5 mitoses per 50 high power fields (HPFs) and a diameter smaller than 5 cm are regarded as benign. In the presented case, up to 4 mitoses per 50 HPFs could be detected and thus, in connection with tumor-size, an uncertain biological behaviour of the process has to be expected. Since no generally accepted consensus on the treatment of the GISTs exists, also patients originally suffering from tumors regarded as borderline-malignant should undergo a close-meshed follow-up in regular intervals.

Adenocarcinoma↗
PubMed2001

[Etiology, clinical aspects and therapy of penoscrotal lymphedema].

Penoscrotal lymphedema has serious functional, cosmetic, psychological and potentially malignant consequences. In contrast to the relatively common occurrence of this disease in areas with endemic filariasis, the incidence in the rest of the world is almost exclusively due to therapeutic sequelae of other illnesses or as congenital entities. As conservative forms of treatment have proved to be inefficient, we discuss different surgical options based on the treatment of 12 patients seen in our clinic. Only the complete excision of the edematous and fibrotic tissues, together with reconstructive methods using local flaps and skin grafts, can guarantee a definitive solution, irrespective of the etiology. A detailed anatomical knowledge of the regional lymphatic drainage pathways allows safe operative treatment. Despite the rarity of this disease, a number of different surgical procedures have been reported in the literature that are compared with the findings in our patients.

Adult↗
PubMed2001

[Congenital pulmonary fibrosarcoma. Differential diagnosis of infantile pulmonary spindle cell tumors].

Primary pulmonary mesenchymal tumors are rare causes of intrathoracic lesions in newborns. We describe a case of pulmonary spindle-cell tumor with features of infantile fibrosarcoma and discuss the differential diagnosis of spindle-cell lesions in this location. In view of further case reports of the literature, this neoplasia can best be categorized in a spectrum of fibroblastic/myofibroblastic differentiated spindle-cell tumors, with excellent prognosis. Especially in congenital lesions a favorable clinical course is to be expected after complete surgical resection. Additional radio- and/or chemotherapy is not recommended.

Diagnosis, Differential↗
PubMed2001

[Pulmonary lymphangioleiomyomatosis. Morphologic and immunohistochemical findings].

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease affecting only women which is characterised by cystic parenchymal changes and smooth muscle proliferation and has to be considered in the differential diagnosis of interstitial lung disease. The LAM cell is classified as a so-called perivascular epithelioid cell (PEC) showing immunohistochemical co-expression of smooth muscle and melanocytic markers (melanomyopericyte). A total of 18 cases of LAM and 56 cases of various other pulmonary diseases were analysed by immunohistochemistry. For the diagnosis of LAM in transbronchial or open lung biopsies, immunohistochemistry using the antibody HMB 45 is decisive because it shows a highly specific and sensitive, but often only faint reaction for pulmonary LAM. The immunohistochemical detection of nuclear localised microphthalmia transcription factor (MiTF) in LAM as an additional melanocytic marker further emphasises the melanocytic (as well as smooth muscle) line of differentiation within the cells of LAM. Using the concept of a melanomyopericyte, pulmonary LAM could be classified as a hamartomatous interstitial lung disease showing perivascular smooth muscle and partial melanocytic differentiation.

Actins↗
PubMed2001

The association between tumour progression and vascularity in myxofibrosarcoma and myxoid/round cell liposarcoma.

Angiogenesis is an important factor in the morphological progression and metastasis of many solid tumours. We studied two homogeneous series of myxofibrosarcoma (MFS) and myxoid/round liposarcoma (MRLS), characterised by distinct vascular patterns and correlated the intratumoral microvessel density (IMD) with morphologic progression in both types of sarcoma. In our study, 43 cases of MFS and 42 cases of MRLS were graded according to established diagnostic criteria. For evaluation of IMD, representative sections were stained immunohistochemically for CD31. After selection of "neovascular hot spots", IMD was calculated by measuring the endothelial surface within twenty 200x fields in relation to the total analysed area. In addition to the correlation of IMD with histological grades of malignancy, a correlation of IMD with the inflammatory infiltrate in MFS was done. To determine whether vascular endothelial growth factor (VEGF) and its receptors, KDR and flt-1, may play a role in the progression of both types of sarcomas, we used mRNA in situ hybridisation (ISH) to study VEGF, KDR and flt-1 expression in selected cases. In addition, the expression of thrombospondin-1, which has been reported to inhibit angiogenesis, and of collagen type I was studied using mRNA ISH. Cases of MFS varied histologically from hypocellular, mainly myxoid, neoplasms (low-grade malignant, 18 cases) to intermediate-grade malignant lesions with increased cellularity and mitotic activity (13 cases), and high-grade malignant cases with marked pleomorphism, high proliferative activity and areas of necrosis in many cases (12 cases). Cases of purely low-grade myxoid liposarcoma (16 cases) were characterised by low-cellularity, mucin pooling and plexiform vasculature. In combined MRLS, these hypocellular areas were admixed with hypercellular, round cell areas (5-80% of the analysed tumour area; 23 cases), and in round cell liposarcoma (three cases) rounded tumour cells predominated (>80% of the analysed tumour area). The average IMD in intermediate and high-grade malignant MFS (4.03 and 4.09, respectively) was significantly higher than in low-grade malignant MFS (2.73). Correlation of vascularity with the inflammatory infiltrate in MFS showed increased IMD only in cases with abundant neutrophils; most of these cases were high-grade malignant neoplasms. In contrast, no statistical correlation between morphological progression and IMD was seen in myxoid liposarcoma (6.08), MRLS (6.57) and round cell liposarcoma (4.07). VEGF mRNA was expressed by tumour cells in all histological grades of MFS and MRLS. VEGF receptor mRNA was weakly expressed by endothelia of newly formed blood vessels in both entities. Interestingly, tumour cells of all analysed cases of MFS strongly expressed collagen type I and thrombospondin-1, while these proteins were not detected in tumour cells of MRLS. In conclusion, morphologic tumour progression in MFS is associated with increased IMD, whereas, in MRLS, no such correlation is seen. Whereas VEGF and VEGF receptor mRNA were expressed in both entities, a characteristic expression profile of collagen type I and thrombospondin-1 in MFS emerged. Further studies are necessary to correlate vascularity and clinical course in MFS and MRLS.

Adolescent↗
PubMed2001

Osteoid osteoma that occurred in a former fracture site.

Diagnosis of osteoid osteoma often is delayed, despite its high incidence, because of similarities in presenting symptoms with other pathologic entities. The current case report describes a posttraumatic osteoid osteoma. Three years after osteosynthesis of a distal tibial fracture an osteoid osteoma was diagnosed at the former fracture site. After excluding osteomyelitis as a possible diagnosis, the tumor was excised successfully. Based on current knowledge of the pathogenesis of osteoid osteoma, it is unlikely that the lesion observed in the patient was attributable to the previous fracture.

Adolescent↗
PubMed2000

[Intramuscular extremity metastasis of adenocarcinoma of the colon].

Metastases from colorectal carcinoma usually spread along abdominal lymph nodes or are hematogenous to the liver or lungs. So far, 13 cases of metastases to skeletal muscle have been described. In the following report, the case of a 72-year-old woman with a colonic carcinoma and metastases of this tumor in the thigh is described. Other reports about muscular metastases of colorectal tumors are discussed.

Adenocarcinoma↗
PubMed2000

Patterns of expression and secretion of vascular endothelial growth factor in malignant soft-tissue tumours.

Vascular endothelial growth factor (VEGF) is an important cytokine especially in the process of tumour angiogenesis. A total of 46 soft-tissue sarcomas were analysed for the expression and possible secretion of VEGF by immunohistochemistry, in-situ hybridisation, and enzyme-linked immunosorbent assays (ELISA). VEGF was demonstrated immunohistochemically in tumour tissue in 45 of 46 cases. The detection of mRNA transcripts yielded evidence of synthesis of VEGF in these sarcomas. ELISA could be performed in 21 cases. Higher concentrations of VEGF were found in tumour-related intraoperatively sampled venous blood in 16 out of 21 patients (76%) than in systemic concentrations taken preoperatively. The results indicated the secretion of VEGF by tumour cells although these raised concentrations were not statistically significant. In 12 out of these 16 patients (75%) a concurrent moderate to strong immunoexpression of VEGF was detected. The relevance of VEGF blood concentrations as a potential "progress parameter" for the course of disease remains questionable. This is mainly due to the lack of statistical significance in the difference between systemic VEGF concentrations in patients and those of a control group. Further long-term follow-up studies are needed, which should include patients with tumour recurrences.

Adolescent↗
PubMed2000

APC and beta-catenin in alveolar soft part sarcoma (ASPS)--immunohistochemical and molecular genetic analysis.

Apart from its role in cell-adhesion, beta-catenin is regarded as an oncoprotein, the cytoplasmic level of which is regulated by APC as a tumor suppressor protein. Changes of chromosome 5q, the region that includes the APC-gene, are known to be important in the pathogenesis of fibromatosis; however, little is known about the significance of APC and beta-catenin in other mesenchymal tumors. Therefore, we used immunohistochemistry and DNA-analysis to investigate four cases of alveolar soft-part sarcoma (ASPS) as a mesenchymal tumor with a distinct histologic appearance. In three cases of ASPS the APC-gene product was found to have strong nuclear expression and only faint cytoplasmic staining. Beta-catenin showed a partly membranous, partly strong intracytoplasmic expression. No gene mutations for APC and beta-catenin were detected in any of the four cases. These investigations suggest that, apart from their function in carcinogenesis and fibromatoses, APC and beta-catenin play a role in the pathogenesis of soft tissue tumors such as ASPS. The significance of a striking nuclear accumulation of non-mutated, virtually functionally active APC-tumor suppressor protein has not yet been investigated. A nuclear function of APC in ASPS in down-regulating nuclear transcription processes linked to overexpression of beta-catenin, as is known in colorectal carcinogenesis, may be hypothesized.

Adenomatous Polyposis Coli Protein↗
PubMed2000

Beta-catenin in soft tissue sarcomas: expression is related to proliferative activity in high-grade sarcomas.

Besides its role in cell adhesion, beta-catenin exerts a function as an oncoprotein. The aim of this study was the characterization of its expression, possible mutation, and the assessment of beta-catenin as a prognostic indicator for soft tissue sarcomas. A total of 115 soft tissue sarcomas were analyzed using immunohistochemistry, immunogold-electron microscopy, and DNA analysis. Information from 56 patients was available for follow-up. A statistically significant correlation was found between intracellular distribution of beta-catenin and the proliferative activity (MIB-1 expression) in high-grade sarcomas (P = .0008). Beta-catenin was identified with intracytoplasmic and nuclear accumulation, showing additional membranous staining in sarcomas with epithelioid pattern. Ultrastructurally, a colocalization between beta-catenin and nuclear heterochromatin was demonstrated. In 22 analyzed tumors, only one (yet undescribed) mutation of the beta-catenin gene (C-A transversion) could be detected. Prognostic validity of the cellular expression of beta-catenin, however, was not proven. Apart from its membranous function as an effective molecule for cell-adhesion in sarcomas with epithelioid pattern, beta-catenin may act as an oncoprotein in sarcomas with intracytoplasmic and nuclear localization with binding to nuclear DNA. A previously discussed stimulation of cell proliferation caused by an increased beta-catenin level can also be postulated for high-grade soft tissue sarcomas in correlation with the rate of proliferation. Mutations of the beta-catenin gene are probably of lesser importance for the accumulation of beta-catenin in soft tissue sarcomas.

Adult↗
PubMed1999

The APC protein binds to A/T rich DNA sequences.

The tumor suppressor protein APC (Adenomatous Polyposis Coli) is localized in the cytosol and in the nucleus. In this study, we demonstrate that the nuclear APC protein level is high in cells in the basal crypt region of the normal colorectal epithelium. Strikingly, the APC protein staining resembles the staining pattern of a nuclear proliferation marker. As a first step towards a possible role of the nuclear APC protein, we provide data showing the direct interaction of the nuclear APC protein with DNA. A nuclear APC isoform precipitates with matrix-immobilized DNA. Vice versa, the immunoprecipitation of APC from nuclear lysates results in co-precipitation of genomic DNA. Using recombinant APC fragments we mapped three DNA binding domains: one within the beta-catenin binding and regulatory domain, and two in the carboxyterminal third of the APC protein. All these three domains contain clusters of repetitive S(T)PXX sequence motifs that were described to mediate the DNA interaction of many other DNA binding proteins. In analogy to S(T)PXX proteins, the APC protein binds preferentially to A/T rich DNA sequences rather than to a single DNA sequence motif.

Adenomatous Polyposis Coli↗
PubMed1999

[Primary synovial sarcoma of the lung].

In the biopsy material of a polypoid intrabronchial lesion of a 54-year-old male patient with radiologically established lung tumor, spindle-cell neoplasia was seen. No clear histogenetic classification of the submucous tumor process was possible. After resection of the right upper lobe of the lung, including the results of additional immunohistochemical analyses, the tumor was classified as biphasic synovial sarcoma. This was suggested mostly by immunohistochemical detection of the epithelial membrane antigene (EMA) and of vimentin. Extensive clinical examinations ruled out the possibility of a primary tumor with extrapulmonary localization. This case report shows the problems faced in correctly classifying the histogenesis or the direction of differentiation in extremely rare cases of primary pulmonary synovial sarcoma. Especially in small biopsy samples showing a submucous spindle-cell tumor of the lung, apart from frequent sarcoma metastases, the presence of primary synovial sarcoma of the lung has to be considered in the differential diagnosis.

Antigens, CD↗
PubMed1999

Intracellular distribution of beta-catenin in colorectal adenomas, carcinomas and Peutz-Jeghers polyps.

The interaction of the adenomatous polyposis coli (APC) tumor-suppressor protein and the intracellular cell-adhesion protein beta-catenin is crucial for the development of colorectal tumors. Since functional nuclear complexes of beta-catenin with transcription factors have been identified recently, the knowledge of level and distribution of beta-catenin in sporadic colorectal tumors will give important insights into the intracellular mechanism of sporadic colorectal tumor initiation and progression. In contrast to the familiar adenomatous polyposis syndrome and to the majority of sporadic colorectal tumors, Peutz-Jeghers (PJ) syndrome is not caused by mutations in the APC gene. Since PJ syndrome is an inherited disease with an increased risk for gastrointestinal adenocarcinoma, whether beta-catenin plays a similarly important role for the development of PJ polyps should be further investigated. For these reasons we analyzed the distribution of beta-catenin in a total of 60 sporadic colorectal tumors at different stages of progression and in 6 PJ polyps. In addition to the localization at the cell-to-cell border membranes, fluorescence immunohistochemistry revealed a nuclear accumulation of beta-catenin in single tumor cells of 10/14 small adenomas with mild dysplasia and in 14/16 adenomas with moderate dysplasia. Further tumor progression is accompanied by an expansion of cells with increased level of nuclear and cytoplasmic beta-catenin. These cells were observed in 5/16 adenomas with moderate dysplasia and in 15/15 adenomas with severe dysplasia. In all adenocarcinomas investigated, as well as in the corresponding lymph node metastases, a sub-population of tumor cells exhibited a remarkably increased level of beta-catenin within the entire cytoplasm and the nucleus. In contrast to the situation in sporadic colorectal tumors, nuclear and cytoplasmic beta-catenin was not increased in PJ polyps. These results point to an extensive redistribution of beta-catenin, which starts early in colorectal tumorigenesis. The nuclear accumulation in single cells of small adenomas can be considered as the first visible sign of the loss of APC function. Thus the immunohistochemical detection of beta-catenin distribution could serve as a criterion for estimating the malignant potential in the clinico-pathological evaluation of colon tumors during their early progression.

Adenoma↗
PubMed1998

Expression and localization of vascular endothelial growth factor and its receptor flt in pulmonary sarcoidosis.

Vascular endothelial growth factor (VEGF) is a multifunctional cytokine, which has recently been reported to enhance the activation and migration of monocytes through the flt receptor in vitro, which are key events in granuloma formation of granulomatous disorders and in sarcoidosis. Since activated macrophages and monocytes are known to be involved in sarcoid granuloma formation in sarcoidosis, we investigated the expression of VEGF and its receptor flt in 33 paraffin-embedded lung tissue biopsies of patients with pulmonary sarcoidosis. VEGF-mRNA was localized by nonradioactive in situ hybridization, VEGF and flt expression were visualized immunohistochemically. We found an increased transcription and protein production of VEGF and an overexpression of flt in activated alveolar macrophages, in epitheloid cells, and in multinuclear giant cells of pulmonary sarcoid granulomas.

Adult↗