Cases reported "Retinoblastoma"

Filter by keywords:



Filtering documents. Please wait...

1/46. Discordant retinoblastoma in monozygotic twins.

    PURPOSE: We report cases of discordant retinoblastoma in twins confirmed to be monozygotic by dna analysis. methods: Twin A demonstrated severe, bilateral, multifocal retinoblastoma, which was recalcitrant to external beam irradiation and chemoreduction. Twin B has not demonstrated retinoblastoma. dna analysis was performed with polymorphic microsatellite markers to confirm monozygosity. Single-stranded conformation polymorphism and Southern blot analysis of the retinoblastoma gene were performed. RESULTS: Molecular genetic analyses confirmed monozygosity but failed to disclose a retinoblastoma gene mutation in either twin. CONCLUSIONS: The extreme phenotypic discordance may best be explained by an unidentified, postzygotic retinoblastoma gene mutation in early embryonic development of the affected twin.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)

2/46. The treatment of retinoblastoma: a case study.

    research in the treatment of retinoblastoma and multidrug resistance has led to new treatment protocols for children. This case study introduces information regarding a clinical trial for the treatment of intraocular retinoblastoma. It also highlights important nursing issues in the care of these children and their families.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)

3/46. retinoblastoma in a patient with an X;13 translocation and facial abnormalities consistent with 13q-syndrome.

    PURPOSE: To report a patient with an X;13 translocation and facial features of 13q-syndrome who developed retinoblastoma. DESIGN: Observational case report. methods: A 9-month-old girl known to have an X;13 chromosomal translocation with a break point at 13q12.1 and dysmorphic facial features characteristic of 13q-syndrome presented with leukocoria in her right eye. RESULTS: By clinical examination, retinoblastoma was diagnosed in the right eye. CONCLUSION: Chromosomal abnormalities on the long arm of chromosome 13 predispose to retinoblastoma formation and characteristic facial features.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)

4/46. Segmentation techniques for tissue differentiation in MRI of ophthalmology using fuzzy clustering algorithms.

    This paper presents MRI segmentation techniques to differentiate abnormal and normal tissues in ophthalmology using fuzzy clustering algorithms. Applying the best-known fuzzy c-means (FCM) clustering algorithm, a newly proposed algorithm, called an alternative fuzzy c-mean (AFCM), was used for MRI segmentation in ophthalmology. These unsupervised segmentation algorithms can help Ophthalmologists to reduce the medical imaging noise effects originating from low resolution sensors and/or the structures that move during the data acquisition. They may be particularly helpful in the clinical oncological field as an aid to the diagnosis of retinoblastoma, an inborn oncological disease in which symptoms usually show in early childhood. For the purpose of early treatment with radiotherapy and surgery, the newly proposed AFCM is preferred to provide more information for medical images used by Ophthalmologists. Comparisons between FCM and AFCM segmentations are made. Both fuzzy clustering segmentation techniques provide useful information and good results. However, the AFCM method has better detection of abnormal tissues than FCM according to a window selection. overall, the newly proposed AFCM segmentation technique is recommended in MRI segmentation.
- - - - - - - - - -
ranking = 2
keywords = formation
(Clic here for more details about this article)

5/46. Skeletal metastases from retinoblastoma.

    Four patients with skeletal metastases from retinoblastomas are presented. Radiologically, the metastases showed periosteal new bone formation and permeative-type bone destruction, particularly involving the long bones of the extremities, and they tended to be bilateral. The metastases resembled those of neuroblastoma and, to a lesser extent, medulloblastoma. The relationship between these three tumors is discussed.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)

6/46. B-scan ultrasonography in the diagnosis of atypical retinoblastomas.

    Contact B- scan ultrasonography (Bronson-Turner unit) was performed on fourteen patients with retinoblastoma. In ten cases, the patient presented with leukocoria, and ultrasonography was helpful in confirming the clinical diagnosis. In four atypical cases contact B-scan ultrasonography was instrumental in making the diagnosis. The ultrasonographic pattern for retinoblastoma is characteristic but not pathognomic. There is a solid intraocular echo corresponding to the tumor and within it are numerous dense focal echoes which persist at lower sensitivities, suggesting calcification. Calcification was demonstrated ultrasonographically and confirmed histologically in all four of these atypical cases, but routine skull x-rays failed to demonstrate calcium in three of the four children. Contact B- scan ultrasonography is a safe and simple procedure which may provide valuable diagnostic information in children with suspected retinoblastoma.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)

7/46. Sinonasal small cell neoplasm developing after radiation therapy for retinoblastoma: an immunohistologic, ultrastructural, and cytogenetic study.

    patients with retinoblastoma have an increased risk of developing second primary tumors. Only a few examples of sinonasal small cell neoplasms developing after radiation therapy for retinoblastoma have been reported. We report one such case that developed 18 years after treatment for retinoblastoma. Histologic examination revealed a small, blue, round cell tumor without rosettes or cytoplasmic glycogen. Immunohistochemically, the tumor cells were positive for neuron-specific enolase, synaptophysin, and S-100 protein, but negative for epithelial and mesenchymal markers, suggesting that this was a primitive neuroectodermal tumor. Cytogenetic studies of this tumor failed to reveal the chromosome 13 abnormality typical of retinoblastoma and the t(11:22) translocation typical of the group of peripheral neuroepitheliomas.
- - - - - - - - - -
ranking = 654.81968646312
keywords = rosette
(Clic here for more details about this article)

8/46. Cytogenetic abnormalities in an ossifying fibroma from a patient with bilateral retinoblastoma.

    cytogenetic analysis of a cemento-ossifying fibroma from a patient with nonfamilial bilateral multicentric retinoblastoma revealed three reciprocal translocations with the karyotype 46,XY,t(1;18)(q21;q21.3),t(3;10)(p13;q22),t(6;11)(p22;p15). Routine and high-resolution cytogenetic analysis of peripheral blood leukocytes showed an apparently normal, 46,XY chromosome pattern with no deletion of chromosome 13. Molecular analysis demonstrated no gross differences in the retinoblastoma gene or the TP53 gene between constitutional and tumor dna. This is the first cytogenetic analysis of a cemento-ossifying fibroma and the first report of this tumor in a retinoblastoma patient. The data may be added to the small, but growing literature on cytogenetic aberrations in benign tumors and may lend insight into genes involved in cell proliferation and neoplastic transformation.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)

9/46. Pineal parenchymal tumor with marked retinoblastic differentiation: case report.

    A 53-year-old woman was found to have a tumor in the pineal region. Histologically, Homer-Wright rosettes were sporadically distributed in a diffuse proliferation of round tumor cells that were immunoreactive for synaptophysin and chromogranin. A few perivascular pseudorosettes were also present, and the perivascular tumor cells were immunoreactive for glial fibrillary acidic protein and vimentin. By electron microscopy, well-developed junctions and pronounced interdigitation of abutting plasma membranes were noted in many tumor cells, as well as abundant intracytoplasmic microtubules. These findings indicated that the tumor was a pineal parenchymal tumor accompanied by an extraordinary epithelial-like differentiation, suggesting retinoblastic photoreceptor cell differentiation.
- - - - - - - - - -
ranking = 1309.6393729262
keywords = rosette
(Clic here for more details about this article)

10/46. Molecular-genetic analysis of two cases with retinoblastoma: benefits for disease management.

    Effective counselling and management of retinoblastoma families using genetic information is presently practised in many parts of the world. We studied histopathological, chromosomal and molecular-genetic data of two retinoblastoma patients from india. The two patients, one with bilateral and the other with unilateral retinoblastoma, underwent complete ophthalmic examination, cytogenetic study, retinoblastoma gene (RB1) mutational analysis and RB1 promoter region methylation screening. In the bilateral retinoblastoma patient deletion of chromosome region 13q14 in peripheral blood lymphocytes and a hemizygous novel 8-bp deletion in exon 4 of RB1 in tumour sample were observed. In the unilaterally affected patient CGA to TGA transition protein truncation mutations were observed in exons 8 and 14 of RB1.
- - - - - - - - - -
ranking = 1
keywords = formation
(Clic here for more details about this article)
| Next ->


Leave a message about 'Retinoblastoma'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.