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M Beatriz S Lopes

Publications and source records attributed to M Beatriz S Lopes.

18 recordsLinked to original sources
PubMed2006

Capillary hemangioma of the cauda equina presenting with radiculopathy and papilledema.

A 42-year-old, non-obese man with a three-month history of headache, pulsatile tinnitus, transient visual obscurations, and scintillations later developed low back pain with right lower extremity radiation. Brain MRI and magnetic resonance venography were normal, but spine MRI revealed a mass in the cauda equina. Neuro-ophthalmologic examination disclosed bilateral optic disc edema with normal visual function. During spine surgery, cerebrospinal fluid, released under high pressure despite prior hyperventilation, contained a glucose level of 51 mg/dl and a protein level of 1840 mg/dl. Histologic and immunohistochemical features of the lesion were compatible with a capillary hemangioma. Although spinal cord tumors have been associated with papilledema, this is the first report of a capillary hemangioma of the cauda equina in this context. If papilledema is present, spinal cord imaging should be performed when lumbar puncture discloses unexplained protein elevation and in cases that lack clinical features typical of idiopathic intracranial hypertension.

Adult↗
PubMed2006

Neuropathological considerations of pituitary adenomas.

Pituitary tumors constitute around 15-20% of intracranial tumors. The understanding of the molecular mechanisms of tumorigenesis and the functional regulation of pituitary adenoma has greatly advanced in the last decade. The current WHO classification scheme of pituitary tumors reflects this progress on tumor biology knowledge, and embraces the most widely utilized diagnostic methods of evaluation of these lesions. The present chapter highlights the different aspects of the tumor diagnosis and reviews the classification of pituitary tumors.

Brain↗
PubMed2006

Pituitary apoplexy: do histological features influence the clinical presentation and outcome?

OBJECT: A retrospective analysis of a contemporary series of patients with pituitary apoplexy was performed to ascertain whether the histopathological features influence the clinical presentation or the outcome. METHODS: A retrospective analysis was performed in 59 patients treated for pituitary apoplexy at the University of Virginia Health System, Charlottesville, Virginia, or Groote Schuur Hospital, University of Cape Town, South Africa. The patients were divided into two groups according to the histological features of their disease: one group with infarction alone, comprising 22 patients; and the other with hemorrhagic infarction and/or frank hemorrhage, comprising 37 patients. The presenting symptoms, clinical features, endocrinological status, and outcome were compared between the two groups. CONCLUSIONS: The patients who presented with histological features of pituitary tumor infarction alone had less severe clinical features on presentation, a longer course prior to presentation, and a better outcome than those presenting with hemorrhagic infarction or frank hemorrhage. The endocrine replacement requirements were similar in both groups.

Adenoma↗
PubMed2006

Primary disseminated leptomeningeal oligodendroglioma with 1p deletion. Case report.

The authors report the case of a 2-year-old boy with a primary, diffuse leptomeningeal oligodendroglioma in which the deletion of chromosome arm lp was identified by performing a fluorescence in situ hybridization (FISH) analysis. This previously healthy child initially presented with malaise, anorexia, nausea, vomiting, and macrocephaly. Imaging studies confirmed the presence of hydrocephalus, and a ventriculoperitoneal shunt was placed. The postoperative course was complicated by emesis, continued weight loss, and numerous seizurelike episodes. A contrast-enhanced magnetic resonance imaging study performed approximately 10 weeks postoperatively showed diffuse leptomeningeal thickening and enhancement without evidence of an intraparenchymal mass lesion. A right frontal lobe brain biopsy revealed a hypercellular proliferation of small oligodendroglioma-like cells, which occupied the leptomeninges diffusely and spared the underlying cortical gray matter. The tumor cells displayed prominent perinuclear clearing and had evenly spaced, uniformly round nuclei. Occasional mitotic figures were observed. Background vessels were thin and delicate, and there was no evidence of necrosis. The tumor cells showed strong immunoreactivity for S100 protein; the results of immunohistochemical staining were negative for glial fibrillary acidic protein, vimentin, epithelial membrane antigen, NeuN, and synaptophysin. The deletion of lp was demonstrated by FISH analysis; lq, 19p, and 19q were intact. This appears to be the first reported case of a primary diffuse leptomeningeal oligodendroglioma in which a lp deletion was identified.

Biopsy↗
PubMed2005

Relevance of high Ki-67 in pituitary adenomas. Case report and review of the literature.

Pituitary adenomas are heterogeneous in growth rate, invasiveness, and recurrence. To understand the biological behavior of the individual adenoma more fully, cell proliferation markers such as monoclonal antibodies targeted against the Ki-67 antigen have been applied. The Ki-67 antigen is a protein related to cell proliferation and is expressed in cell nuclei throughout the entire cell cycle. The authors report the case of an extremely rapidly growing pituitary adenoma with cavernous sinus invasion. The lesion, which displayed a high Ki-67 labeling index (LI; 22%), was found in a 54-year-old woman who presented with diplopia and headaches. The patient underwent three transsphenoidal operations in less than 6 months and, ultimately, was treated with fractionated intensity-modulated radiation therapy. The relationships between high Ki-67 LIs and tumor recurrence, invasiveness, and growth velocity in pituitary adenomas are reviewed.

Adenoma↗
PubMed2005

Lucien J. Rubinstein: enduring contributions to neuro-oncology.

Dr. Lucien Rubinstein is best remembered for his significant contributions to the field of neuropathology, particularly in the classification of nervous system tumors. His accomplishments in basic neuro-oncology and in the formulation of diagnostic principles reflected a unique talent for synthesizing fundamental clinicopathological concepts based on skillful diagnostic investigation and a thorough understanding of neurobiology. Dr. Rubinstein was the leader in the establishment of cell cultures from central nervous system (CNS) tumors. He meticulously analyzed both light and electron microscopic features of CNS tumors, recorded his findings, and patiently drew sketches to be shared generously with his colleagues and students. As a pioneer in neuropathology, in his work Dr. Rubinstein set the foundation for many enduring concepts in neurosurgery, neuro-oncology, neurology, and basic tumor biology.

Biomarkers, Tumor↗
PubMed2005

Spindle cell oncocytoma of the adenohypophysis: report of two recurrent cases.

The recently described "spindle cell oncocytoma of the adenohypophysis" is a very rare and often misdiagnosed entity. A benign biologic behavior has been suggested based on the absence of recurrences with a median follow-up of 3 years. Herein, we present 2 cases of recurrent spindle cell oncocytomas. One patient is a 71-year-old woman (case no. 1) and the other a 76-year-old man (case no. 2). Recently, both underwent transsphenoidal reexploration for recurrent "pituitary adenoma." Patient no. 1 had initial surgery 11 years ago with a recurrence after 3 years that was initially stable. Ultimately, a partial resection was performed after compression of optic pathways by the tumor, and approximately 1 year later, re-resection was carried out. Patient no. 2 had initial surgery 10 years ago with recurrence and resection after 3 years. He recently presented with a large mass that involved the pituitary fossa and base of the skull, with extension into the nasopharynx and nasal cavity. The primary and recurrent lesions of both cases showed similar architecture with interlacing fascicles of spindle cells that alternated with areas of epithelioid-like cells that exhibited eosinophilic, granular cytoplasm. Neoplastic cells were positive for vimentin, S-100 protein, and epithelial membrane antigen, and negative for glial fibrillary acidic protein, chromogranin, and pituitary hormones. Increased mitotic activity was noted in 1 lesion (case no. 2), although both cases had high Ki-67 indices (18% and 20%, respectively). The ultrastructural features of both cases were characteristic with intracytoplasmic accumulations of large mitochondria. The histopathologic features of these lesions are consistent with spindle cell oncocytoma of the adenohypophysis. In summary, we are reporting 2 cases of recurrent spindle cell oncocytoma of adenohypophysis with longer follow-up than previously published cases, suggesting the possibility of a more aggressive behavior than has been initially considered.

Adenoma, Oxyphilic↗
PubMed2005

Pituitary carcinoma: diagnosis and treatment.

Pituitary carcinomas are rare pituitary tumors that by definition have cerebrospinal and/or systemic metastases. Most of the tumors occur in the setting of multiple recurrences of invasive pituitary adenomas. This article reviews the clinical presentation of these tumors, their neuroimaging and pathological features, tumor pathogenesis, and possible treatment modalities.

Antineoplastic Agents↗
PubMed2005

The Ki-67 labeling index as a prognostic factor in Grade II oligoastrocytomas.

OBJECT: This study was conducted to determine whether proliferative tumor activity, as assessed using the Ki-67 immunohistochemical labeling index (LI), has prognostic utility for patients with Grade II oligoastrocytomas. METHODS: The study period spans the years 1988 to 2000. In a retrospective analysis, the authors selected cases with biopsy-proven diagnoses of Grade II oligoastrocytomas on initial presentation. The authors added new patients to this group and followed all patients prospectively at the University of Virginia Neuro-Oncology Center. Twenty-three adult patients were followed for at least 1 year (median 40.3 months). Eleven patients with Grade II tumors and initial Ki-67 LIs less than 10% had a significantly longer median time to tumor progression (TTP, 51.8 months compared with 9.9 months) and a longer median survival (93.1 months compared with 16.1 months) than 12 patients with initial Ki-67 LIs of 10% or greater. Twelve patients with Grade III oligoastrocytomas had a mean TTP that was similar to the TTP of patients with Grade II tumors and high Ki-67 LIs (mean 4 months compared with 9.9 months) and duration of survival (13.3 months compared with 16.1 months). CONCLUSIONS: Patients with a Grade II oligoastrocytoma and a Ki-67 LI of 10% or greater have a much shorter TTP and potentially a poorer disease prognosis than expected--more similar to patients with a Grade III oligoastrocytoma. These results indicate that in the future a measure of proliferative activity should be taken into consideration along with the World Health Organization grading criteria for oligoastrocytomas.

Adult↗
PubMed2004

Brain metastases.

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Antineoplastic Agents↗
PubMed2003

Angiogenesis in brain tumors.

Angiogenesis is a complex process regulated by multiple stimulatory and inhibitory factors that are able to modulate the migration and/or proliferation of microvascular cells with the objective of formation of neovasculature from preexisting vessels. It involves well-coordinated steps including production and release of angiogenic factors, proteolytic degradation of extracellular matrix components to allow formation of capillary sprout, proliferation and directional migration of microvascular cells, and the final composition of new vessels [Senger (1996) Am. J. Pathol. 149:1-7]. Angiogenesis is present in a number of hypoxic and/or ischemic conditions in the central nervous system, in particular in infarctions and infectious processes. Angiogenesis also plays an important role in malignant primary tumors. Glioblastomas, the most malignant gliomas in adults, are among the most angiogenic of all human tumors. This review will examine recent data of the role of angiogenic growth factors in the neoplastic and reactive conditions in the brain.

Angiogenesis Inhibitors↗
PubMed2003

Intrasellar schwannomas: report of two cases.

OBJECTIVE AND IMPORTANCE: The complex regional anatomic features surrounding the sella turcica make the differential diagnosis of intrasellar and parasellar lesions complicated. Sellar and parasellar schwannomas are rare. With the exclusion of parasellar schwannomas arising from cranial nerves within the cavernous sinus and extending into the sella, there have been only two reported cases of true intrasellar schwannomas. CLINICAL PRESENTATION: We describe the clinical, radiological, and pathological features of two cases in which the histopathological diagnosis of schwannoma was confirmed with immunohistochemical analyses and/or electron microscopy. INTERVENTION: The two cases were grossly resected via a transsphenoidal approach. Follow-up monitoring revealed no evidence of recurrence. CONCLUSION: Schwannomas may atypically occur in the sellar region, in which they demonstrate the typical light microscopic, immunohistochemical, and ultrastructural features observed in the peripheral nervous system. New and existing hypotheses regarding the histopathogenesis of intrasellar and parasellar schwannomas are presented.

Adult↗
PubMed2002

Expression of survivin, an inhibitor of apoptosis protein, in tumors of the nervous system.

Survivin is an inhibitor of apoptosis protein that blocks apoptosis by binding to caspases-3 and -7. It is highly expressed in less-differentiated embryonic cells and rapidly dividing tumors, but not in terminally differentiated adult tissues. Elevated survivin levels are found in malignant systemic tumors, and are associated with chemo-resistance, radiation resistance, and poor prognosis. However, expression of survivin in primary nervous system tumors has not been previously characterized. Immunohistochemistry using anti-human survivin antibody (SURV11-A) was performed on formalin-fixed, paraffin-embedded archival tissue from 112 primary central nervous system tumors. Survivin immunoreactivity was seen in most diffuse astrocytomas [WHO II (2/4), III (3/3), IV (9/10), giant-cell glioblastoma (1), and gliosarcoma (1)]. The intensity and degree of survivin expression showed trends with tumor grade, with glioblastomas having the highest positivity. Pilocytic astrocytomas (5) and pleomorphic xanthoastrocytoma (1) were positive to a lesser degree. In oligodendrogliomas (6) and mixed oligo-astrocytomas [grade II (5), II-III (3), and III (7)], oligodendroglial elements appear to be negative compared to positive mini-gemistocytic oligodendrocytes. Ependymomas [grade II (6) and grade III (1)] were positive. Medulloblastomas (5) and retinoblastoma (1/4) showed focal positivity. All meningiomas [grade I (12), II (9), III (4), and grade I (3) and II (5) with frank brain invasion] were intensely positive. All schwannomas (11) and neurofibromas (6) were intensely positive. Thus, survivin is expressed in the majority of the primary nervous system tumors, particularly in glioblastomas, meningiomas, schwannomas and neurofibromas. Overexpression of survivin in meningiomas and benign peripheral nerve sheath tumors contrasts with previous reports relating it to rapid division and poor prognosis.

Astrocytoma↗
PubMed2002

Low-grade central nervous system tumors.

Low-grade tumors of the central nervous system constitute 15 to 35% of primary brain tumors. Although this category of tumors encompasses a number of different well-characterized entities, low-grade tumors constitute every tumor not obviously malignant at initial diagnosis. In this brief review, the authors discuss the pathological classification, diagnostic procedures, treatment, and possible pathogenic mechanisms of these tumors. Emphasis is given in the neuroradiological and pathological features of the several entities.

Central Nervous System Neoplasms↗
PubMed2002

April 2002: 35-year-old healthy man with enlarging right parotid mass.

The April 2002 Case of the Month (COM). 35-year-old healthy man developed a mass in the right parotid gland. A superifical parotidectomy was performed for a 4.5 x 1.5 x 1.5 cm mass involving the intraparotid facial nerve. Grossly the tumor was multinodular, smooth and yellow with normal surrounding salivary gland. Microscopically, the tumor showed expanding nodules composed of proliferating fibroblasts, Schwann cells, and perineural-like cells in a myxoid stroma. Normal peripheral nerve twigs were identified in the periphery of the tumor. There was no increased mitotic activity, cellularity or nuclear pleomorphism. S-100 immunohistochemical stain was positive. The tumor was diagnosed as a solitary plexiform neurofibroma. Plexiform neurofibromas in this area have been described in children with von Recklinghausen's disease or neurofibromatosis 1 (NF 1). Plexiform neurofibromas typically involve deep seated nerve trunks and is considered pathognomonic for NF 1. This unusual case represents a solitary variant of plexiform neurofibroma presenting as a parotid mass in an adult patient without a personal stigmata or family history of NF 1.

Adult↗
PubMed2002

Hemangiopericytoma in the setting of acromegaly.

Acromegaly is associated with an increased incidence of neoplasia thought to be related in part to tonic increases in circulating levels of insulin-like growth factor-1 (IGF-1). Hemangiopericytomas, particularly those occurring in soft tissues, are known to possess IGF receptors. These tumors often behave aggressively and can be recalcitrant to surgery and radiation therapy. A 49-yr-old man presented with an erosive, midline scalp mass and cutis gyrata. Further diagnostic imaging and endocrinologic analysis confirmed two diagnoses: a hemangiopericytoma and acromegaly associated with an intrasellar pituitary tumor. Both the hemangiopericytoma and the pituitary adenoma were surgically resected; Western blot analysis confirmed the presence of IGF-1 receptors in the hemangiopericytoma. Two years later, the patient underwent resection of a right frontal hemangiopericytoma with an identical histologic phenotype and receptor positivity for IGF-1. The occurrence of a central nervous system hemangiopericytoma in patient with acromegaly is rare. Growth and recurrence of hemangiopericytoma may have been fostered by the presence of IGF-1 receptors. Paracrine mechanisms related to IGF-1 may have contributed to its pathogenesis and growth. The presence of IGF-1 receptors in hemangiopericytomas may have treatment implications for additional adjuvant therapies.

Acromegaly↗
PubMed2002

Primary sellar lymphoma: radiologic and pathologic findings in two patients.

We describe the clinical, MR imaging, and pathologic findings in two cases of primary sellar lymphoma in immunocompetent individuals. Both patients had hypopituitarism, and one patient had a sixth cranial nerve palsy. MR images depicted sellar and suprasellar masses in both patients, and extension into the cavernous and sphenoid sinuses was also present in one patient. The pathologic diagnosis in both cases was large B cell lymphoma.

Aged↗