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Ocular Tumors
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Vishal Raval, Alexander Melendez, Hansell Soto, Alléxya Affonso, Rubens Belfort Neto, Arun D. Singh
This genetic form occurs in 10% of children. These children are born with a change in one copy of the RB1 gene in every cell in the body (“first hit”). The mutation in the other copy of the RB1 gene, the “second hit,” occurs in a retinal cell some time after conception. The inherited gene mutation is highly penetrant and nearly all – about 90% – of such children develop retinoblastoma. Most children with the genetic form develop bilateral retinoblastoma. Some children with the familial form develop pinealoblastoma (trilateral retinoblastoma).7 The other clinical variant, retinoma, is an uncommon benign form of retinoblastoma.
Central Nervous System
Published in Pat Price, Karol Sikora, Treatment of Cancer, 2020
The management of pineal tumors includes imaging the entire neuraxis, immediate decompression of hydrocephalus, and establishing a tissue diagnosis. Pineocytoma is a surgical disease and may be cured by total resection. Pineoblastoma is less likely to be cured by surgery, although complete resection should be attempted where possible. There is evidence that whole-neuraxis radiotherapy with the boost directed at the tumor improves outcome, particularly if resection is incomplete. Chemotherapy responses can also be seen. Intermediate (Grade 2/3) tumors present particular difficulties in management. Again, complete surgical excision should be attempted where possible. The need for radiotherapy will depend on the completeness of resection, the mitotic rate, and evidence of dissemination away from the primary.
Radiotherapy for Pediatric Central Nervous System Tumors – Techniques and Strategies
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Pineoblastoma was previously classified as an embryonal tumor but in the 2016 WHO classification is grouped with the pineal parenchymal tumors. However, management strategies still follow those of embryonal tumors with surgery, CSI, and local boost and multiagent chemotherapy.44,45
Comment: conservative management of massive choroidal relapse in retinoblastoma patients?
Published in Ophthalmic Genetics, 2018
In case 1, the authors state that the child was initially diagnosed with unilateral bifocal IIRC group B tumor at 7 months of age. Was genetic testing performed for the child to look for hertitable pattern of retinoblastoma? This could have lead to more frequent and close monitoring of the child with magnetic resonance imaging (MRI) for screening and early detection of pinealoblastoma. The authors state that SD OCT could detect early signs of choroidal invasion 3 weeks prior to the visit when the lesion was clinically detected. What was the timing of the first examination at the subclinical stage of the lesion? Did it coincide with the time of starting intensive induction adjuvant chemotherapy for pinealoblastoma? In that case, how does one explain the choroidal mass growing in size while the child continued to receive cycles of intensive adjuvant chemotherapy and then finally regressing completely, while attributing the regression to adjuvant chemotherapy itself.
Response to Khetan and Maitray’s “Comment: Conservative management of massive choroidal relapse in retinoblastoma patients?”
Published in Ophthalmic Genetics, 2018
Christina Stathopoulos, Marie-Claire Gaillard, Francesco Puccinelli, Philippe Maeder, Doris Hadjistilianou, Maja Beck-Popovic, Francis Munier
The authors ask if the child in case 1, who suffered unilateral retinoblastoma and developed pinealoblastoma had genetic testing performed, that could have led to MRI screening and early detection of pinealoblastoma. RB1 gene sequencing had been performed but failed to reveal a germline mutation. Despite that, the child was undergoing routine screening brain MRI for early diagnosis of pinealoblastoma, as she was suffering unilateral bifocal retinoblastoma, which allowed us, as mentioned in the manuscript, to diagnose an asymptomatic pineal mass.
Molecular Genetics of Intraocular Tumors
Published in Seminars in Ophthalmology, 2020
Mehenaz Hanbazazh, Thaddeus P. Dryja
Retinoblastoma can be heritable or nonheritable. Heritable retinoblastoma, which accounts for about 45% of all cases,11,18 occurs in patients with a germline mutation in the RB1 gene. Tumors in such patients arise from cells that lose the remaining RB1 allele. The loss of the second allele occurs by chromosomal mechanisms leading to the loss of heterozygosity (which accounts for more than half of the tumors),23,24 or by somatic mutation, or by hypermethylation of the RB1 promoter. 80% of heritable cases are bilateral,11,18,25 and they are at elevated risk to develop additional cancers later in life, especially bone and soft tissue sarcomas. Intracranial tumors, mainly arising in the pineal gland (pinealoblastoma), occur in approximately 5% of hereditary cases (trilateral retinoblastoma).26 If a parent has heritable retinoblastoma, the children have a 45% chance of being affected (50% risk of inheritance of the germline mutation and 90% penetrance).25 Most heritable retinoblastoma cases arise from a new germline mutation.3,18,26–29 The germline RB1 mutation is typically present in all the patient’s cells (preconception mutation). In occasional cases, it is in only a subset of cells in which case the patient is a “mosaic” (postconception mutation).,11,18,25 Rare families with hereditary retinoblastoma demonstrate low penetrance (many unaffected carriers) with reduced expressivity (many affected members having only one tumor).,11,16 This low penetrance can be caused by germline RB1 mutations that are hypomorphic (i.e, they are not null mutations but instead mutations that allow weak activity of the mutant pRB).,11,18,30 Another cause can be a balanced chromosomal translocation.31 Finally, large deletions of chromosome 13q including the RB1 gene can have low penetrance. Dehainault et al. identified MED4 as a survival gene and suggested that the low penetrance in patients with a large deletion of chromosome 13q results from the loss of both the RB1 gene and MED4 gene.32