Biomedical subjects
Publications and source records attributed to G Goovaerts.
A case of a chondrosarcoma in a patient with relapsing polychondritis was presented. The association of these two unusual disorders of cartilaginous tissue has never been described before. The clinical presentation and radiologic and histologic features were discussed.
The vascularisation of human primary colorectal carcinomas was studied immunohistochemically using the endothelial cell markers CD31 and factor VIII-related antigen. Tumour sections were systematically scanned at a magnification of x 100 to find areas of intense neovascularisation. Microvessel counts within these vascular 'hotspots' were performed at magnification x 250. Regions in which tumour cords were surrounded by a collagen IV-positive basement membrane were compared with those in which this was absent and with normal mucosa. CD31 appeared to be a more sensitive marker for endothelial cells than factor VIII-related antigen (mean 185 +/- 59 and 120 +/- 38 microvessels mm-2). Within individual tumour sections microvessel counts in vascular hotspots with highest vessel density correlated significantly with microvessel counts in vascular hotspots with second highest vessel density (P < 0.01). Microvessel counts in tumour areas where collagen IV-positive basement membrane were absent exceeded those in areas where it was present (factor of 1.7) and those in normal mucosa (factor of 1.6). The differences in vessel density between individual tumours and the low variability in vessel density within individual tumours using this quantification technique allow us to investigate the prognostic value of vessel density in areas of intense neovascularisation in human primary colorectal carcinomas.
BACKGROUND: Thymidine incorporation studies performed in animal tumour models, revealed major differences in endothelial cell proliferation when tumour tissue was compared with normal tissue. The fraction of proliferating endothelial cells is reported to be increased by a factor of 30 to 40 in tumour tissue. PATIENTS AND METHODS: To make it possible to analyze the endothelial cell proliferation in human tumours, an immunohistochemical double staining technique comprising CD31, an endothelial cell marker, and Ki-67, a proliferation marker, was developed. Endothelial cell proliferation was analysed in 21 primary human colorectal adenocarcinomas and in the adjacent mucosa. RESULTS: Proliferating endothelial cells were found throughout the entire carcinoma. The mean overall endothelial cell labeling index (ECLI) was 9.9% (range, 5.4-18.0), and the labeling index of endothelial cells in areas of intense neovascularisation was even higher. Mean ECLI in the vascular hot spots was 21.0% (range, 6.8-35.0), and the mean tumour cell labeling index (TCLI) in the maximally Ki-67 immunostained areas was 78.3% (range 47.0-89.7). In 14 of 21 carcinomas, these areas were predominantly found at the luminal margin of the tumour, as were the vascular hot spots. A significant positive correlation was found between tumour vascularity, measured in the vascular hot spots, and tumour cell proliferation, measured in the maximally Ki-67 immunostained areas (p < 0.05). To analyse this relation in more detail, microvessel density (MVD), TCLI and ECLI were determined per x400 microscopic field by scanning in sequence from the luminal tumour margin to the invasive tumour base. In all tumours, the pattern of the MVD per x400 field, from the luminal margin to the tumour base, was similar to that of the TCLI and ECLI. CONCLUSIONS: These findings confirm that the fraction of cycling endothelial cells is higher in human colorectal carcinoma than in the adjacent mucosa which suggests that endothelial cells are proliferating in most of the individual capillaries in tumour tissue. Regional differences in MVD correlate with differences in tumour cell proliferation in these tumours.
We report the cytogenetic findings in a case of malignant melanoma of soft parts. Overrepresentation of 1q together with a del(1)(q42), extra copies of chromosomes 7 and 8, and t(12;22)(q13;q13) were found. These findings allow further delineation of the chromosomal pattern found in this uncommon neoplasm.
Changes in the basement membrane (BM) in atrophic tubules in human kidney biopsies were studied by electron microscopy and by immunohistochemistry on cryostat sections with antibodies against collagen type I, type III, type IV, laminin, EMA, keratin and vimentin. The BM showed different degrees of thickening with formation of reduplications which contained fibrocytes. Remnants of cytoplasm of epithelial cells and fibrocytes were incorporated in the thickened BM. This showed signs of lysis and disintegration, indicating that the redundant BM formed by the epithelial cells is removed, although imperfectly, by interstitial cells. Thinning of the BM was another frequent finding. Immunohistochemistry showed a clear reactivity for collagen type IV and laminin in all BM material. The epithelial cells showed multilayering and a peculiar type of dark cells extending underneath adjacent cells and separating them from their BM attachment.
A case of neonatal respiratory distress due to an oropharyngeal hairy polyp is reported with its MRI assessment. The place of hairy polyps in the differential diagnosis of upper respiratory tract obstruction is discussed. Early and rapid diagnosis and treatment may be lifesaving for the newborn.
Fourteen nevi with neuroid zones were examined and compared with nine nevi without neuroid structures. At light microscopic level, nevus cells from the neuroid nevi and the control nevi show the same staining pattern with polyclonal antibodies against S-100 protein. Around the cells of the neuroid zones is a more intensive immunoreactivity with monoclonal antibodies against laminin and collagen type IV than around the nevus cells in the upper dermis and the nevus cells in the control nevi. Also, the Gordon-Sweet stain for reticulin shows a dense network around the cells of the neuroid zones. No immunoreactivity in the neuroid zones was found with monoclonal antibodies against myelin-basic protein, myelin-associated protein, and glial fibrillary acidic protein. At the electron microscopic level, nevus cells from the neuroid zones show stacks of elongated cytoplasmic processes surrounded by basal lamina material. This pattern explains the presence of the abundant cytoplasm seen at light microscopy. Because no features of neural or neurolemmal differentiation could be found, the exactitude of the term neurotization can be questioned.
A symptomatic anterior mediastinal mass in a 44-year-old woman was found to be a benign thymic cyst. Complete excision was made by anterolateral thoracotomy. Congenital cysts are benign but differentiation from malignant cystic degeneration should be made.
Nevus cells show considerable variation in their appearance, depending on their localization in epidermis, upper dermis, or deep dermis. The difference in appearance of nevus cells when located superficially or in the deep dermis has been referred to as nevus cell "maturation." The aim of this study is to objectify morphological differences between nevus cells in epidermis, upper dermis, and deep dermis by means of a morphometric study at light- and electron microscopic levels. The results show that there is a decrease in number and size of all structures except for mitochondria and microfilaments. These findings are consistent with atrophy. The concepts of maturation, differentiation, and atrophy are also discussed.
In order to study factors which influence the subjective grading of bladder cancers the hypothesis of an ideal examination system was tested. The subjective results were compared with morphometry on the nuclear size of non selected cells. The results show that with precise criteria, with examination of the total section surface field by field and with recording of a grading per field a better interobserver consistency can be obtained. Morphometry demonstrates the heterogeneity and the Gaussian distribution of nuclear sizes in normal and diseased urothelium. It shows that subjective grading is influenced by a small number of larger nuclei and that even in grade 3 tumours 50% of the nuclei have sizes within normal values.
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The number, intracellular distribution, and staining characteristics of human hepatocellular peroxisomes that had been made visible by cytochemical staining for catalase were evaluated in biopsies from 75 patients with hepatic, inflammatory, or malignant disease and ten normal individuals. Intensity of staining was found to be proportional to enzymatic activity by microspectrophotometry. Scanning transmission electron microscopy (STEM) image analysis demonstrated an inverse relationship between peroxisomal size and contrast. Peroxisomes were more abundant, and often concentrated in a perinuclear configuration in cholestatic and cirrhotic livers. Decreased peroxisomal staining was common in cholestasis, cirrhosis, hepatitis, and in almost all patients with malignancies, both with and without hepatic metastases.
A right paratracheal mass in a 56-year-old man was found to be a primary intrathoracic goitre. Pathological examination showed nodular hyperplasia with focal lymphocytic thyroiditis. Enlarged mediastinal thyroid tissue may result from extension of a cervical goitre into the chest and is then called secondary or may develop from ectopic thyroid tissue located in the mediastinum and is then called primary. In the latter case blood supply comes from local intrathoracic vessels and no connections with the cervical gland are observed. Differentiation can be made by ultrasonography, CT scanning or radioisotope scanning. Primary goitres are best operated on by way of a thoracotomy as troublesome mediastinal bleeding may occur which is difficult to control from a cervical collar incision.
The clinical history, radiological investigations, pathologic findings and treatment of four patients affected by retroperitoneal leiomyosarcoma were compared with data of the literature. These tumors have a great tendency to develop local recurrences after excision, but metastases to lymph nodes and distant organs usually occur lately. CT examination of the retroperitoneal space is a sensitive tool in the diagnosis and follow-up. Complete excision of the tumor followed by radiotherapy improves significantly the prognosis. Chemotherapy is advisable only when disseminated metastases appear. No correlation was found between the histologic appearance and the clinical behaviour.
Endometriosis has been encountered in different sites of the gastrointestinal tract. Involvement of the vermiform appendix, however, is rather unusual. Two cases of appendiceal endometriosis are reported in the present study: one patient had symptoms simulating acute appendicitis; in another patient it was an incidental finding during pelvic surgery. There are no clinical signs and findings pathognomonic of endometriosis of the appendix, but the condition may present as appendicitis. At surgery, the diagnosis can only be suspected when it is associated with obvious genital endometriosis. Correct diagnosis is established by microscopic examination of the lesion. Symptomatic endometriosis of the appendix will be cured by appendectomy.
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