retinoblastoma
TRANSCRIPT
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By Abril SantosUniversidad Popular Autónoma del Estado de Puebla
International Observership Program
Retinoblastoma
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Most frequent malignant intraocular tumor during childhood. 1/15,000 – 1/20,000 • Greater amount due to better treatments.• Age of diagnosis depends on socio-economic conditions.
Introduction
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Age of Diagnosis* Type of Retinoblastoma
12 months Bilateral (20-30%)
24 months Unilateral
18 months Total average
Unilateral Bilateral*Average
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Genetic Characteristics
Presentation of Retinoblastoma• Sporadic (94%)• Family History (6%)
• Due to an spontaneous mutation• 80% of the cases is somatic• The other 20% is germinal - heritage
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Knudson’s TheoryFor a retinoblastoma to exist 2 mutations are required to happen.
Hereditary1°- Germinal
(In all the cells)2°- Somatic mutation
NON Hereditary1° y 2°- Somatic
2 mutations must occurConsecutively in the same ȼ
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NON HereditarySomatic + somatic mutation : Single
tumor. Unilateral.Late start (2 years)
HereditaryGerminal + somatic mutation : Bilateral,
multifocal tumor.Early start (1 year)
Unifocal Multifocal
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Retinoma* Associated Lesions
*Retinoma is a benign variant, initially considered a tumor regression, but recent evidences suggest that it rather represents a pre-malignant lesion.
1. Spontaneous Regression of Retinoblastoma2. Spontaneous Growth arrest of Retinocytoma or Retinoma
Phthisis Bulbi Retinal Scars
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Hereditary
RetinoblastomaMore likely to present another kind of tumor.• Osteosarcoma• Pinealoblastoma (Trilateral
retinoblastoma)
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Development of the eye from the neural tube. Optic vesicles and the inverted optic cup are forming the retina.
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The RB1 has a longitude of 180,388 pairs of bases and 27 exons.
The RB1 gen is localized within the 13th chromosome in the q14.2 region.
Retinoblastoma
GEN
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pRb Functions*
Whatever type of mutations results in increased RB phosphorylation and inactivation of RB function.
*Inhibits the progression of the cellular cycle before the mitosis
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PRb1 y P53
• Rb1 y P53 are in charge of stopping damaged cells into the cellular cycle. • So, if these are damaged, there will be a filtration of abnormal cells.
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Clinical Features• Asymptomatic – Early stage.• Leukocoria (66% - 1st sign)• Strabismus (20%)• Hyphema• Rubeosis iridis• Mydriasis• Areflexic pupils• Secondary Glaucoma• Hypopyon
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CLINICALFINDINGS
1st2nd
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Diagnosis
• Fundus examination
• Eye ultrasound
• Head CT
• MRI
• Fluorescein Angiography
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Types of Retinoblastoma
Exophytic Endophytic
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Endophytic.- Invading vitreous, retinal vascular tortuosity and dilation.Variant: Diffuse infiltrative *Simulates endophthalmitis with hypopyon*Exophytic.- Invades subretininan space, vasculature goes over the tumor.• Variant: Flat retinoblastoma
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1-Initial stage 2
3 4-Advanced
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Extra Ocular Invasion
Orbit and optic nerve are invaded in very advanced cases,
specially when there is secondary glaucoma.
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Treatment• Optic nerve ablation to prevent invasion. • Ocular enucleation• Chemotherapy and Radiotherapy
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After Treatment
• Ocular Implants• Ocular Prosthesis
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Types of Implants
1. Mesh-wrapped Bioceramic
2. Bioceramic
3. Egg-shaped Bioceramic
4. Silicone
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Types of Prosthesis
1. Plastic Acrylic2. Cryolite glass (only a few)
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Differential Diagnosis
Osteosarcoma Cataract Pseudo-retinoblastoma
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Causes for Pseudo-retinoblastoma
Coat’s Disease Persistent Fetal Vasculature
Vitreous Hemorrhage
Ocular Toxocariasis
04/14/2023 27Comparison of two cases of a Retinoblastoma
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References1. Shields C, Schoenberg E, Kocher K, Shukla S, Kaliki S, Shields J. Lesions Simulating Retinoblastoma (Pseudoretinoblastoma) in 604 Cases. Ophthalmology. 2013;120(2):311-316.2. Gil-Gibernau J, Galan Terraza A. Retinoblastoma y otras causas de leucocoria en el nino. [S.l.: s.n.]; 1984.3. Turaka K, Shields C, Bianciotto C, Shields J. Pinealoblastoma and Pineal Cysts among Patients with Intraocular Retinoblastoma Treated with Chemotherapy. International Journal of Radiation Oncology*Biology*Physics. 2011;81(2):S297-S298.4. Shields J, Shields C, Shields J. Eyelid, conjunctival, and orbital tumors. Philadelphia: Lippincott Williams & Wilkins; 2008.5. Rodriguez-Galindo C, Wilson M. Retinoblastoma. New York: Springer; 2010.6. Knudsen et al, University of Cincinnati, in a study of 2000 stated that pRB is not only involved in the regulation of the G1/S Checkpoint but it is also required for an intra-S-phase response to DNA damage.