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Biomedical subjects

G Chomette

Publications and source records attributed to G Chomette.

At least 55 records · Page 3Linked to original sources

[The value of a study of the microvascularization and the cellular immunosurveillance of precancerous states and micro-cancers of the oral cavity].

In 35 patients with leukoplakia or erythroplastic lesions of oral mucosa, the immunohistochemical study of Langerhans cells and various types of lymphocytes demonstrated increasing changes in cellular immunoreactivity in benign leukokeratosis, dysplasia and in situ or microinvasive carcinoma. Besides, the study of alkaline phosphatase activity by means of histoenzymological methods proved an intense angiogenesis during the occurrence of cancerization.

Cell Transformation, Neoplastic↗

[Constrictive pericarditis and Whipple's disease].

The authors report the case of a 61 year-old patient treated by tetracycline for very probable Whipple's disease who developed constrictive pericarditis requiring pericardectomy. Although intestinal biopsy was negative, histological examination of the resected pericardium was very suggestive of a cardiac localisation of Whipple's disease, showing a fibrous pericarditis with a mononuclear infiltration including PAS-positive histiocytes. In addition, the same histological changes were found in a small fragment of myocardial biopsy. This case illustrates the prevalence and consequences of cardiac involvement in Whipple's disease.

Cineradiography↗

[Congenital and acquired right ventricular dysplasia].

Arrhythmogenic right ventricular dysplasia has been described as a developmental malformation occurring during foetal life. This explains a number of familial cases of this condition where dysplasia was the result of a genetic abnormality transmitted in an autosomal dominant mode with incomplete penetrance. Histological data of peroperative or post-mortem specimens of 27 cases showed a large number of grape-like lymphoplasmocytic infiltrations. These appearances suggest an inflammatory origin of the disease, most probably related to an infective etiology. The authors suggest that in addition to the congenital form there may also be a possibility of acquiring arrhythmogenic right ventricular dysplasia after an episode of myocarditis.

Adult↗

[Pathology of degenerative aortic valve insufficiency].

The authors studies 154 cases of degenerative aortic regurgitation which presented macroscopically with atrophic changes of the valve and sometimes with hypertrophy and calcification. Histologically, the essential abnormality was the finding of mucopolysaccharide deposits dissociating the corpus spongiosa from the corpus fibrosa. Depending on the importance of these lesions, three degrees of severity can be defined, the most extensive (84% of our patient population) appearing to be typical of the disease. In addition, mild mitral valve prolapse (5%) and medial necrosis of the aortic wall (80% of patients undergoing aortic biopsy) were observed. These morphological features are on the whole quite different to those of other aortic valve pathologies (rheumatic, endocarditis). However, the border line with other pathologies with a similar anatomopathological substratum is less clearly defined: genetic abnormalities (Marfan's syndrome, Lobstein's disease, etc...) or age-related degenerative disease. The pathogenesis is not clearly understood but could be related to regional disturbances in collagen metabolism with collagenolysis predominating.

Aortic Valve↗

[Intermediate and late changes in human cardiac graft].

Chronic rejection, the most serious complication in long-term survivors of cardiac transplantation, was studied in 5 cardiac grafts obtained at retransplantation and in 15 post-mortem studies of patients who had survived 3 months to 10 years after transplantation. The usual clinical presentation was cardiac failure. Coronary angiography was performed in several cases and showed narrowing and non-opacification of small arteries often accompanied by thrombosis. Histology showed three types of vascular rejection: the most characteristic one, usually observed after the 6th month, was a stenosing fibrous endarteritis; another type of rejection, occurring earlier, was associated with acute myocardial rejection and presented as an inflammatory arteritis; the third type of vascular rejection was accompanied by widespread atheromatous lesions. The significance and pathogenesis of these lesions are discussed with respect to the clinical context with electron microscopic and immuno-histochemical data.

Adult↗

[Extra-nodal lymphoma of the cervicofacial region: anatomo-pathological aspects].

The B lymphomas formed the great majority (greater than 90%) of lymphomas in a series of 80 extra-nodal lymphomas of the cervico-facial region, all categorised by immuno-histochemistry. They also tended to be tumours of the highly malignant type (61%): lymphoblastic, immunoblastic, centroblastic and Burkitt's lymphomas.

Facial Neoplasms↗

[Lymphoma of the salivary glands. New nosologic frontiers].

The classification of salivary lymphomas, including the ambiguous Mikulicz syndrome, has been considerably modified in recent years thanks to advances in immuno-histochemistry. Following the distinction between pseudo-lymphoma and true lymphoma, made possible by the latter, the situation has now become less clear due to the existence of possible transition between the two entities. Moreover, the increasing identification of a particular form of lymphoma involving the salivary glands in Sjogren's syndrome (MALT type lymphoma - centrocytic-like) analogous to that seen in the gastrointestinal tract, now opens up the possibility of very early diagnosis of these tumours. However, the significance in terms of treatment of this monoclonal variant as a tumour criterion still remains difficult to define.

Diagnosis, Differential↗

[Peritoneal mesothelioma].

On the basis of 5 personal cases with illustrations and a review of the literature, the authors emphasize the clinicopathological features of peritoneal mesotheliomas, rare primary tumors for which the histological diagnosis is often difficult. The classical evidence by contact with asbestos fibers is obtained in every second case only. The tumor is often associated with a pleural lesion. Ultrasound and CT currently aid in the diagnosis, usually in a context of extensive ascites. The prognosis is poor. For technical reasons, surgical exeresis most often remains partial in the diffuse forms. Chemotherapy is rarely effective.

Adolescent↗

[Neurologic involvement in malignant mid-face granuloma].

We report 4 cases with neurological disorders due to lethal centrofacial granulomas of unknown origin, and we review the relevant literature. This puzzling disease is characterized by a relentless ulceration of the nose progressing toward the base of the skull, and frequently involving the cranial nerves, the meninges and later the central nervous system. The main clinical point in such situations is to ascertain that no microorganism, no cancer, no specific disease is responsible for the centrofacial lesions, since the microscopic findings may be non-specific. When the entire work-up to exclude all differential diagnoses is completed, the clinician has to deal with lethal centrofacial granuloma. This seems to be a heterogeneous disease, in most of the cases close to malignant T lymphomas. Management is based on radiotherapy, chemotherapy and renutrition with treatment of frequent infectious complications. The prognosis is poor.

Adolescent↗

[Contribution of immunologic technics to the characterization of lethal midline granuloma of unknown origin].

The lethal midline granuloma is a clinical entity characterized by a relentless ulceration of the upper airway involving the nose, the palate and the face, without any demonstrable etiology. We have applied the cell membrane immunostaining techniques to twelve cases. According to the results, it seems that most of the cases are in fact T-cell lymphomas with membrane staining consistent with either precursor or mature lymphoid T-cells. Some cases, however, exhibit an immunostaining pattern compatible with other origins, the proliferating cells belonging either to the B lymphoid or to the histio-monocytic lineages. We conclude that the lethal midline granuloma is an heterogeneous group of neoplastic diseases, in the most part close to a T cell lymphoma, but with a remarkable clinical unity.

Granuloma, Lethal Midline↗

Hemolytic uremic syndrome in patients with Behçet's disease treated with cyclosporin A: report of 2 cases.

Hemolytic uremic syndrome (HUS) has been reported in patients treated with cyclosporin A (CsA) following bone, hepatic and kidney transplantation. We report two patients with Behçet's disease (BD) under CsA treatment because of severe uveitis, who developed HUS several months after the initiation of treatment. Renal biopsies showed lesions consistent with the diagnosis of the arterial form of thrombotic microangiopathy: vascular thrombosis with extensive glomerular ischemia. Renal failure persisted after withdrawal of CsA: one patient is in chronic renal failure (CRF) with a 4-year follow-up; the other died after refusal of chronic hemodialysis. In our two patients, excessive doses of CsA with high trough levels are likely to have contributed to the development of HUS. A rapid adjustment of CsA doses and an early detection of signs of the microangiopathic process might have prevented this severe complication of CsA treatment.

Adult↗

[Nerve sheath myxoma. A case involving the maxillary sinus].

A myxoma of nerve sheaths involving the maxillary sinus was observed in a 12 year-old boy. The tumour, necrotic and calcified in this central area, was detected by a radiological opacity. In this periphery, the histological features were characteristic, showing lobules surrounded by fibrous tissue. In these lobules, spindle-shaped or stellate tumour cells were scattered in an abundant "myxomatous" matrix. The child is in good health fifteen months after surgical treatment. The histogenesis of this rare tumor is discussed in relation to this case and to those cases previously reported in the literature.

Child↗

[Metastasis of a malignant melanoma simulating a primary mandibular sarcoma].

The rare case reported here was a mandibular metastasis of a malignant melanoma located in the nape of the neck and surgically removed. 4 years later, occurred a fibrosarcomatous mandibular tumour without local recurrence. The metastatic nature of this tumour was difficult to prove by means of immunohistochemical and ultrastructural methods. This case illustrated the eventuality of a desmoplastic change in metastasis of a common malignant melanoma. The histogenesis of this rare type of melanoma was discussed.

Diagnosis, Differential↗

[Pyknodysostosis. An unusual form of osteopetrosis].

The case reported here illustrates a rare variety of hereditary osteodysplasia, the pyknodysostosis. The patient, a 34-years-old man, had an history of prior fractures. He took medical advice for a mandibular osteitis consecutive to a tooth extraction. The clinical examination detected a dwarfism accompanied by cranial deformities and abbreviated terminal phalanges of the fingers. The histological study was performed on the mandibular sequestrum and on the adjacent bone. Besides of chronic osteitis, it exhibited an intense osteo-condensation with changes in collagen frame by polarized lumen. As to the 2 molars implanted in the sequestrum, they were ankylosed because of the loss of periodontal ligament. About this case, the differential diagnosis with osteopetrosis and cleidocranial dysostosis and the pathogenesis of the disease are discussed.

Adult↗