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Biomedical subjects

G A de León

Publications and source records attributed to G A de León.

17 recordsLinked to original sources
PubMed1998

A new reciprocal translocation (12;22)(q24.3;q11.2-12) in a malignant rhabdoid tumor of the brain.

We report a malignant rhabdoid tumor (MRT) of the brain with a novel reciprocal translocation, t(12;22)(q24.3;q11.2-12). Previous reports of chromosome abnormalities in MRTs were characterized either by monosomy or partial deletions of chromosome 22. An unbalanced translocation has been identified in only a single case. To our knowledge, the present report is the first to describe a balanced reciprocal translocation in an MRT of the brain. The identification of this subtle translocation further sublocalizes the chromosomal breakpoint on chromosome 22, and could be of potential diagnostic value in cerebral MRTs.

Brain Neoplasms↗
PubMed1996

Digitate intravascular appendages and aneurysm of the vein of Galen.

Peculiar intravascular appendages were found in a case of aneurysm of the vein of Galen. Such appendages consisted of finger-like polypoid growths which protruded within the lumen of ectatic cerebral veins and arteries. They were solid, relatively large, and non-branching. Histologically, their structure was comparable to that of a vessel wall, but was concentrically laminated around the longitudinal axis. Some appendages were associated with thrombi. It is suggested that appendages of this kind probably represent secondary vascular malformations, that they are likely to develop in reaction to abnormal hemodynamic strains upon the vessel walls, and that they might be thrombogenic and, therefore, potentially beneficial for patients with arteriovenous shunts.

Cerebral Veins↗
PubMed1996

Amylaceous (polyglucosan) bodies in familial cerebral atrophy of early onset.

An 8-year-old girl and her 4-year-old sister presented with psychomotor retardation during the 1st year of life. This was followed by spasticity, seizures, and in the older patient, progressive loss of faculties and death. Computed tomographic and magnetic resonance imaging scans demonstrated progressive cerebral atrophy in both patients. Postmortem examination in the older sibling showed diffuse atrophy of the supragranular layers of the cerebral cortex, atrophy and gliosis of the white matter, and accumulation of numerous amylaceous (polyglucosan) bodies within the cytoplasm of cell processes. The inclusions were closely associated with atrophy of the parenchyma. The findings suggest that this disorder is different from other childhood diseases in which amylaceous bodies accumulate within the brain.

Adipose Tissue↗
PubMed1996

Monstrous, crablike hypertrophy of the cerebellar vermis and its relationship with Lhermitte-Duclos disease. Case report.

The case of an infant with a peculiar tumorous malformation of the cerebellum is described. The tumor apparently developed as an exophytic, hypertrophic sprout of the inferior vermis. It had a monstrous appearance resembling a crab, with a metameric body and multiple pairs of limbs attached to the folia of both cerebellar hemispheres. Histologically, the lesion was formed by poorly differentiated neuroepithelial cells without any evidence of organization into nuclei, cortex, or fascicles. Clinically, the tumor behaved in indolent manner and did not regrow after subtotal surgical resection. Because of its gross appearance and its biological behavior, this unusual hamartoblastomatous growth is readily distinguished from medulloblastoma. The morphology of the cerebellum in Lhermitte-Duclos disease is reviewed, and a new interpretation of its basic structure is proposed. This and other known types of cerebellar hypertrophy are different from the malformation in the present case.

Brain Neoplasms↗
PubMed1995

Single forebrain ventricle without prosencephaly: agenesis of the corpus callosum with dehiscent fornices.

Coalescence of the cerebral ventricles with formation of a single forebrain ventricle is described in an unusual case of agenesis of the corpus callosum with dehiscent fornices and severe hydrocephalus. The cerebral hemispheres were fully cleaved. The detached fornices were widely separated from the thalami. The membrana tectoria was retroverted over the midbrain and cerebellum, where it joined the fornices and merged with a curved membranous ependymal dome which, at a great distance, circumvented the thalami as it extended toward the anterior commissure. Other anomalies included arhinencephaly, multiple subependymal heterotopias, and Dandy-Walker malformation. Similar malformations have been described as interhemispheric cysts, as (holo)prosencephaly, or as "midline telencephalic dysgenesis." The basic features of prosencephaly and agenesis of the corpus callosum are reviewed and compared to the present case.

Agenesis of Corpus Callosum↗
PubMed1995

Persistent respiratory failure due to low cervical cord infarction in newborn babies.

Perinatal infarction of the spinal cord is described in two premature babies who survived for several months. In both cases, there was bilateral, multisegmental infarction at the lower cervicothoracic arterial zone (inferior cervical sector), predominantly within the territory of the anterior spinal artery. Clinically, both infants had acute respiratory failure, diaphragmatic respiration, intercostal paralysis, bell-shaped deformity of the thorax, and bilateral arm paresis. Intubation and ventilator support were required for weeks. Eventual extubation was followed by recurrent respiratory failure, atelectasis, and pneumonia. At the level of the infarction, multiple, scattered scars were found in central, perimedullary, and intramedullary arteries, but not in their parent vessels. The etiology of the angiopathy was not determined. These cases demonstrate that discrete arterial infarction of the cord can occur in premature babies, and that such a lesion should be considered in the differential diagnosis of neonatal respiratory failure.

Arteries↗
PubMed1990

Cerebral rhinocele, hydrocephalus, and cleft lip and palate in infants with cardiac fibroma.

Cardiac transplantation was performed in two infants with unresectable fibromas of the myocardium. In one patient, lip surgery was also required for unilateral cleft lip and palate. At autopsy, communicating hydrocephalus of mild to moderate degree was found in both cases. In the patient with facial clefts, there was also a large, ipsilateral cyst, or rhinocele, of the olfactory lobe. This unusual lesion, which seems to represent a previously unreported malformation, was apparently formed by segmental dilatation of a persistent olfactory ventricle. Cerebral or cranial anomalies are thought to be rare in cases of cardiac fibroma; however, macrocephaly was present in five patients. Furthermore, presenting abnormalities among previously reported cases included hydrocephalus in one case, and cleft lip and palate in another. These and other findings suggest that, at least in some cases, cardiac fibroma is a manifestation of a more extensive developmental disorder.

Brain↗
PubMed1988

Olfactory hamartomas in tuberous sclerosis.

Gross or microscopic glial hamartomas were found in the anterior olfactory lobe and olfactory germinal layer of three babies, two of them newborns, with tuberous sclerosis. In two cases microscopic hamartomas were seen in the anterior olfactory lobe, and in one of them there was a prominent nodular tumor of the olfactory tract and trigone. In addition, in both of these cases there were bilateral germinal layer tumors between striatum and septum, at the junction of the obliterated olfactory recess and the frontal horn of the lateral ventricle. Only microscopic hamartomas were present in the olfactory germinal layer of the third case. Typical subependymal germinal layer tumors were also present elsewhere in all cases; however, cortical tubers were recognized in only two of them. In all three patients, the clinical presentation and death were due to cardiac rhabdomyomas. The findings suggest that olfactory hamartomas might be relatively common in tuberous sclerosis. Involvement of olfactory structures is not surprising because the lesions seem to originate in the germinal layer, a region of the brain which is prominently involved in the disease.

Brain Neoplasms↗
PubMed1987

Agenesis of the corpus callosum and limbic malformation in Apert syndrome (type I acrocephalosyndactyly).

Agenesis of the corpus callosum and malformation of limbic structures are described in a patient with Apert syndrome, a disorder characterized by acrocephaly, severe syndactyly, and often, mental retardation. Including the present case, malformation of the corpus callosum and/or limbic structures apparently has been reported in a total of ten patients with the syndrome. Complete or partial agenesis of the corpus callosum was found in six patients, septal defects in three, and arhinencephaly and ammonic hypoplasia in one. Since malformation or limbic structures are, to our knowledge, a consistent feature of agenesis of the corpus callosum, it seems that limbic abnormalities could be important for the pathogenesis of mental retardation not only in Apert syndrome, but also in other acallosal patients.

Acrocephalosyndactylia↗
PubMed1986

Congenital Pick cell encephalopathy: a distinct disorder characterized by diffuse formation of Pick cells in the cerebral cortex.

Diffuse degeneration of the cerebral cortex and claustrum was found in the brain of a 7-week-old baby with profound psychomotor retardation, multiple ankyloses, seizures, and hypothalamic dysfunction. There was ubiquitous Pick cell formation and gliosis in the affected gray matter. The cortex was not atrophic; in fact, the brain was moderately enlarged. The clinical and pathological findings suggest that the disorder should be distinguished from Pick's disease, as well as from other congenital encephalopathies.

Cerebral Cortex↗
PubMed1985

Histological and ultrastructural features of dystrophic isocortical axons in infantile neuroaxonal dystrophy (Seitelberger's disease).

The histological and ultrastructural features of axonal swellings are described in a cerebral biopsy specimen from a 6-year-old girl with infantile neuroaxonal dystrophy. In agreement with previous reports, several swellings were identified as axonal terminals, and it is postulated that the prevailing axonal swellings in cerebral cortex represent dystrophic boutons. Microscopically, dystrophic cortical boutons are morphologically different from typical subcortical spheroids and can be easily identified in routine histological preparations. Five ultrastructural elements were present in most axonal swellings: clusters of characteristic membranous bodies, stacks of elongated membranes, mitochondria, groups of vesicles, and an amorphous matrix. In spite of widespread axonal enlargement, the cerebral cortex was not thickened, and, in fact, the gyri looked atrophic in computerized axial tomograms. These findings suggest that some normal cortical element must be deficient, but such a structure remains to be identified.

Axons↗
PubMed1984

Amyotrophic cerebellar hypoplasia: a specific form of infantile spinal atrophy.

Lower motor neuron degeneration, cerebellar hypoplasia, atrophy of pons, olives, and cerebellum, sclerosis of thalamus and pallidum, and deficient myelination were found in a 2-months-old baby with laryngeal paralysis, mental retardation, progressive amyotrophy, and slow nerve conduction velocity. Such changes seem characteristic of an unusual syndrome previously referred to as "cerebellar hypoplasia in Werdnig-Hoffmann disease", or "anterior horn cell disease with pontocerebellar hypoplasia". Although the pathologic changes in lower motor neurons are indistinguishable from those in other cases of infantile spinal muscular atrophy, the consistent reproducibility of a complex pathologic pattern suggests that this is probably a manifestation of a separate disease process. The term "amyotrophic cerebellar hypoplasia" (ACH) is a convenient designation for the syndrome.

Atrophy↗
PubMed1977

Globoid cells, glial nodules, and peculiar fibrillary changes in the cerebro-hepato-renal syndrome of Zellweger.

In addition to a distinct malformation (pachymicrogyria, heterotaxic lamination of the cerebellar cortex, olivary dysplasia), unusual degenerative changes were found in the nervous system of 2 unrelated babies with the Zellweger syndrome. Cerebral clefts were present in 1 case. In both infants there was neuron loss and accumulation of glial nodules and globoid cells in the gray matter as well as degeneration of the white matter. There was fatty change in astrocytes and diffuse gliosis. Neurons in the column of Clarke and the lateral cuneate nucleus showed peculiar fibrillary changes. Cytoplasmic inclusion bodies were seen in the spinal ganglia. Swelling of cortical astrocytes was remarkable in the older infant. The combination of a rare malformation with the cell changes described here gives the syndrome a unique neuropathological profile.

Basal Ganglia↗
PubMed1976

Cerebellar microgyria.

The histological features of cerebellar microgyria are described in a 15 month old infant. The bizarre appearance of this malformation seems to be the result of two basic factors: secondary fusion between preformed folia, and deficient and disorderly formation of the internal granule cell layer. The findings support the view according to which cerebellar microgyria is probably due to a pathological process involving the external granule cell layer during a relatively late period of cerebellar development.

Autopsy↗