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M Polivka

Publications and source records attributed to M Polivka.

33 records · Page 2Linked to original sources
PubMed1996

AIDS-associated cytomegalovirus infection mimicking central nervous system tumors: a diagnostic challenge.

We reviewed cases of cytomegalovirus (CMV) infection of the central nervous system (CNS) that initially masqueraded as tumors in 37 of 543 consecutive patients infected with human immunodeficiency virus (HIV) and CMV who were seen at the Pasteur Institute Hospital and Saint-Louis Hospital (Paris) between 1992 and 1994. We detail the clinical features of three patients who presented with ring-enhanced space-occupying lesions mimicking CNS tumors. They were all profoundly immunodepressed (mean CD4 cell count, 13/mm3). Magnetic resonance imaging (MRI) showed enlargement of the spinal cord in one case, consistent with a space-occupying lesion and showing gadolinium enhancement; in the other two cases, ring-enhanced mass lesions were seen in the cerebral hemispheres. In all three cases marked edema and a mass effect were present. Image-guided stereotactic biopsies confirmed the diagnosis of CMV infection. The three patients' conditions improved with specific therapy. MRI showed enhanced focal intraparenchymal lesions consistent with marked focal necrosis, probably related to the severity of immunodepression, as HIV infection had been diagnosed several years previously. CMV infection should be considered as a cause of ring-enhanced space-occupying mass lesions in patients with HIV-1 infection. Earlier identification of these unusual tumorlike forms of CMV infection by means of MRI should result in improved outcome.

AIDS-Related Opportunistic Infections↗
PubMed1995

[The epidemiology of cerebral lymphoma in AIDS].

Cerebral lymphomas are one of the complications of AIDS. Their increasing frequency, especially in the last decade, has to be correlated with the incidence of systemic lymphomas and especially central nervous system (CNS) lymphomas in non immuno-compromised patients. CNS involvement is found in 40% of systemic lymphomas. Primary lymphomas have an incidence of 0.4-0.56% in epidemiological studies and 7.6% in post-mortem series. Primary lymphomas are noted in all patients, homosexuals, drug-addicts, children, with a lower rate in the haemophiliacs. Known risk factors are HIV itself Epstein-Barr virus almost constantly demonstrated in tumour cells. Epidemiological studies on cerebral lymphomas must still be completed as, until recently, they were included in the group entitled lymphomas, and risk factors have to be specified with more accuracy.

Brain Neoplasms↗
PubMed1994

[Intramedullary localization of a primary cerebral lymphoma in AIDS].

A 36 years-old male with AIDS, presented with left hemiparesis revealing a right parietal tumour. Stereotactic biopsy demonstrated a malignant non-Hodgkin's lymphoma. His condition partially improved following radiotherapy and chemotherapy. Three months later he was re-admitted with progressive bilateral root pain and urinary incontinence resulting in paraplegia with sensory loss below T10. He died one month later from generalized sepsis. Neuropathology confirmed an immunoblastic B-cell malignant non-Hodgkin's lymphoma in the white matter of the right parietal lobe and revealed a centrospinal localisation of the lymphoma in the thoracic cord at T10. There was no visceral localisation of the tumour. Secondary spread to the spinal cord of malignant non Hodgkin's lymphomas, usually causes meningo-myelo-radiculitis. Intraspinal deposits of primary cerebral lymphomas are uncommon and have never been previously described in AIDS, to our knowledge. Their pathogenesis is unclear. In our case, neuropathological findings are consistent with diffusion of the primary tumour to leptomeninges and secondary infiltration of the spinal cord along the perivascular spaces.

Adult↗
PubMed1994

[Seven cases of subependymoma. Anatomoclinical study and review of the literature].

Subependymomas are uncommon, benign, slowly growing lesions usually located in the fourth ventricle. Their morphology is characteristic, but their histogenesis remains controversial. Seven cases observed in our laboratory over a period of 7 years are reported. Most tumors were located axially in the brain stem, and symptoms were more variable than usually reported. The histological appearance was fairly uniform. Immunohistochemistry showed that the fibrillary component was composed of glial fibers. Ependymary differentiation is inconstant on electron microscopy. The pathogenesis of the lesion (tumor, hamartoma or reactive proliferation) is debated in the literature as is the histogenesis.

Adult↗
PubMed1993

Biodegradable starch microspheres for cerebral arterial embolization.

RATIONALE AND OBJECTIVES: Various materials have been used to perform intracerebral and cervical arterial embolization for head and neck tumors and vascular malformations. This preliminary prospective study was designed to analyze the clinical and histopathologic consequences of arterial embolization into the brain using biodegradable starch microspheres. METHODS: A new arterial embolization procedure which ensured the integrity of the common and internal carotid arteries, without modifying the arterial flow, was designed. The procedure allowed for cerebral arterial microembolization in 20 Sprague-Dawley rats. Various amounts of biodegradable starch microspheres (Spherex) were introduced into the brain via the left external carotid artery. RESULTS AND CONCLUSIONS: Clinical and histopathologic results suggested that: 1) consequences of cerebral embolization using biodegradable starch microspheres are related to the amount of material embolized; and 2) Spherex microspheres behave differently from degradable microspheres in the brain. Despite the rapid biodegradability of the material, permanent damage from ischemia to the brain was noted.

Animals↗
PubMed1993

[Report of a case of rhabdomyosarcoma of the central nervous system. Histologic, immunohistochemical and ultrastructural study].

A patient, aged 26, had a large parietal tumor, clinically revealed by intracranial hypertension and left sized paresthesia. Removal of tumor was followed by a rapid recurrence. Rhabdomyosarcoma was diagnosed on the second surgical specimen. These tumors are rare in the central nervous system. They occur mostly, though not exclusively, in young adults. Their prognosis is poor and their histogenesis is still unclear.

Adult↗
PubMed1993

Immunohistochemical detection of cell proliferation in gastric carcinomas with the monoclonal antibody Ki-67. A study of 24 cases.

The proliferative activity in 24 gastric carcinomas was determined by an immunohistochemical method using monoclonal antibody Ki-67 (ABC method). Immunostained nuclei were counted by two observers through a Nachet NS 1000 image numeriser. Three grades were defined according to stained nuclei percentage (proliferation index Pi = percentage of cells engaged in cellular cycle outside Go): grade 1 (Pi < 20%); grade 2 (20% < Pi < 40%); grade 3 (Pi > 40%). About 60% of tumours were in grade 1 and 10% in grade 3. No correlations were observed between Pi and the following parameters: histological differentiation; parietal extension; presence or absence of metastasis. These results may be compared to the two other available studies of Ki-67 antibody in gastric cancers. Our study also showed a heterogeneous distribution of immunostained nuclei, within each single tumour and from one tumour to another, which has been noted in one previous study and in a similar one we made on colorectal carcinoma. This heterogeneity is the consequence of the variability of carcinomatous cell proliferative activity; an important biological factor in the evaluation of tumoral process. The proliferative activity in gastric carcinomas provides an estimation of tumour dynamics that might be a prospective criterium for tumoral process evaluation.

Antibodies, Monoclonal↗
PubMed1992

Watershed cerebral infarcts: retrospective study of 24 cases.

Twenty-four patients presenting an acute stroke with watershed cerebral infarct on CT scan or MRI were included in this retrospective study. Age was 63 +/- 14 years (mean +/- SD), and sex ratio was 2 men for 1 woman. Main clinical features were: in anterior location, lower limb weakness and frontal syndrome with transcortical motor aphasia in left lesions or spatial dyscalculia in right ones; in posterior location, brachiofacial weakness with constant quadranopsia and hypoesthesia, and Gerstmann syndrome in left lesion. There was no distinctive feature for subcortical and multiple infarcts. In bilateral infarcts, there were one pseudobulbar syndrome, and 2 pseudo brainstem syndromes with neuropsychological signs. Aetiologies were severe carotid artery disease in 14 cases, severe cardiopathy in 6, isolated cerebral angiitis in 1, essential thrombocythemia in 1, protein C deficiency with sickle cell disease in 1, and cholesterol emboli in 1 anatomical case. CBF performed in carotid artery occlusions or tight stenoses showed evidence of haemodynamic changes. Microembolic process can be proposed in the case with cholesterol emboli. Preventive treatment is discussed.

Cerebral Infarction↗
PubMed1992

[Cisternal cysticercosis of the cerebellopontine angle. A surgically-treated case and review of the literature].

Most neurocysticercosis (N.C.C.) cases reported occur in undeveloped countries where contaminated food by Taenia solium gives rise to human infection. People of developed countries are exposed by migrations and travels. We report a case of a 36 years old french woman living at La Reunion. Her symptomatology consisted of left unilateral hypoacusis progressing over a two years period accompagnied by intermittent headaches. CT scan showed a hypodense mass with a ring enhancement in the left cerebello pontine angle (C.P.A.). M.R.I. showed multicystic arrangement of vesicles in a racemous fashion that spread out to peduncular and carotid cisterns. Parenchymatous or ventricular involvement was not observed. A lateral suboccipital craniectomy was carried up in the sitting position. After division of a thickened arachnoid in the C.P.A., the vesicles were dissected an pulled out easily because the membranes had not any adhesions. Progressive improvement of hearing was observed in the next week. Primary cisternal involvement of N.C.C. is rare and, in literature, there is not any other reported case in the C.P.A. Different mechanisms of invasion to the C.N.S. are discussed.

Adult↗
PubMed1990

Serotonin-producing pancreatic endocrine tumour. Histological, ultrastructural and immunohistochemical study of a case.

Serotonin-producing pancreatic endocrine tumours are rare neoplasms which in most cases exhibit malignant biological behaviour. These tumours, in the majority of the well-documented cases, are composed of argyrophil- and argentaffin-positive cells which contain large pleomorphic neurosecretory granules. In contrast, argyrophilic non-argentaffin pancreatic endocrine tumours with tumour cells containing round neurosecretory granules are exceptional. In this study we describe such a tumour not associated with clinical evidence of carcinoid syndrome in a 60-year-old woman. Histological examination revealed tumour extension in pancreatic lymphatic vessels and veins but no evidence of locoregional or distant metastases. Ten months after surgery the patient showed no recurrence of the disease. Immunohistochemistry revealed cytoplasmic serotonin production in the tumour cells which were negative for anti-gastrin, insulin, glucagon, somatostatin, pancreatic polypeptide (PP), vasoactive intestinal peptide (VIP) and ACTH. This study emphasizes the usefulness of combined ultrastructural and immunohistochemical investigations in order to identify and characterize the rare pancreatic endocrine tumours with serotonin production.

Adenoma, Islet Cell↗
PubMed1989

Immunohistochemical detection of proliferating cells in colorectal carcinomas and adenomas with the monoclonal antibody Ki-67. Preliminary data.

Twenty one cases of colorectal adenocarcinoma and six of adenoma have been studied using the monoclonal antibody Ki-67 which recognizes a nuclear antigen expressed by proliferating cells (PC). The quantitative evaluation of the stained nuclei showed that PC were more numerous in carcinomas than in adenomas although the difference did not reach a significant level. In each tumour, heterogeneity was noted. Furthermore, the superficial areas of both carcinomas and adenomas contained a greater number of PC than the deep. No difference was noticed in the various types and grades of differentiation for carcinomas. This preliminary report, compared with the only previous study of Shepherd et al. (1988) outlines the interest of the monoclonal antibody Ki-67 in the evaluation of growth fractions in colorectal tumours.

Adenoma↗
PubMed1989

Middle ear adenoma. A tumor displaying mucinous and neuroendocrine differentiation.

Middle ear adenoma (MEA) is a distinctive, rare entity that appears to be derived from the lining epithelium of the middle ear mucosa. We report four cases of MEA displaying the typical histologic growth pattern. Two distinct tumor cell immunophenotypes were identified in all cases; the first type exhibited positivity with anti-epithelial membrane antigen and anti-keratin antibodies, and the second type showed immunoreactivity with anti-keratin, anti-vimentin, and anti-neuron-specific enolase antibodies. Ultrastructural studies revealed bidirectional mucinous and neuroendocrine differentiation, demonstrated by the presence of two distinct cell types containing apically located mucous granules and basally concentrated neuroendocrine granules, respectively. The presence of neuroendocrine differentiation was supported by the immunohistochemical detection of vasoactive intestinal polypeptide in the tumor cells in one case and neuron-specific enolase in three cases. These findings suggest that the potential for mixed mucinous/neuroendocrine differentiation described in other endodermally derived tumors also exists in middle ear mucosa. We also believe that the rare lesions diagnosed as primary carcinoid tumors of the middle ear might in fact be MEA with predominant or only neuroendocrine differentiation. The clinical course of our four cases and our review of the pertinent literature confirm the benign nature of MEA and indicate that these tumors should be treated by complete local excision without additional therapy.

Adenoma↗
PubMedDate not supplied

MR manifestations of subependymomas.

PURPOSE: To provide a description of the MR and enhanced MR appearances of subependymomas. METHODS: We reviewed the MR examinations of eight cases of pathologically proved subependymomas and correlated them with operative and pathologic reports, and also reviewed the previous published cases of subependymomas documented by MR. Gadopentetate dimeglumine-enhanced MR examination was performed in seven cases. RESULTS: One patient presented with four subependymomas, two patients had subependymomas of the cervical spine, and the others were intraventricular with no transependymal extension. They were isointense to hypointense relative to normal white matter on T1-weighted images, heterogeneous in five cases. Minimal (n = 1) or no (n = 3) enhancement was noted in four cases, and moderate or marked enhancement was noted in three cases. CONCLUSION: We conclude that even though there is no specific sign of subependymomas, when confronted with a complete intraventricular lesion or with a spinal lesion causing little or no edema which is minimally enhancing or nonenhancing, one must consider the diagnosis of subependymoma.

Adolescent↗