Retinoblastoma Flashcards
A 2-year-old boy with unilateral retinoblastoma has undergone enucleation of the right eye. Pathology of the enucleated eye shows a retinoblastoma occupying 90% of the vitreous cavity with massive choroidal involvement as well as disease exending past the lamina cribrosa. The cut margin of the optic nerve is negative for tumor cells. MRI of the brain (including lymph nodes), bone marrow aspirates and biopsies, and cerebrospinal fluid are negative for disease.
Next step ?
This patient has high-risk pathology and elevated risk of recurrence, and therefore adjuvant chemotherapy is indicated.
Adjuvant chemotherapy with six cycles of vincristine, carboplatin, and etoposide (VCE)
Bilateral retinoblastoma one eye group D and one eye group B
Chemotherapy can be given systemically or by direct delivery into the ophthalmic artery (intra-arterial, IA) noting that this patient is >3 months of age so above the threshold to be able to consider IA therapy).
Laser therapy (thermotherapy or photocoagulation) and cryotherapy are extremely important in the management of intraocular retinoblastoma; however, group B and D eyes, as is seen in this patient, need chemoreduction first followed by focal treatments.
This patient has a good chance of bilateral ocular salvage and vision preservation, particularly the group B eye.
Group E retinoblastoma treatment
Upfront enucleation is reserved for bilateral patients who have advanced (Group E) disease with concern for high risk for metastatic spread (abnormalities on MRI including optic nerve thickening, extraocular extension into orbit) or with additional high risk features present at diagnosis such as neovascular glaucoma or necrotic disease.
Even advanced Group E eyes may show some response to adjuvant chemotherapy and focal therapy, preserving at least some vision even in the worst appearing eye.
Group A retinoblastoma treatment
Focal treatments (laser and cryotherapy) only, with no chemotherapy, is only recommended for group A eyes.
Group E features:
group E eye is defined by the presence of advanced intraocular disease, with the presence of one or more of the following poor prognosis features:
i. Tumor touching the lens
ii. Tumor anterior to the vitreous involving the ciliary body or the anterior segment
iii. Diffuse infiltrating retinoblastoma
iv. Neovascular glaucoma
v. Opaque media from hemorrhage
vi. Tumor necrosis with aseptic orbital cellulitis
vii. Phthisis bulbi (shrinkage and disorganization of the eye globe)
Bilateral disease in mom , what is the risk for the baby? no identified genes.
The mother in this vignette was treated for bilateral retinoblastoma, and, although no mutation was identified, she has heritable disease and a 50% chance that her offspring will be affected.
The baby should be evaluated by an ophthalmologist within 3-4 weeks after birth with a full fundoscopic examination and have blood sent for RB1 mutation after birth.
The red reflex is a screening evaluation for all infants/children, but it is not sufficient in cases with a known family history of heritable retinoblastoma because it cannot accurately identify early group (A-C) disease.
High risk histopathology in retinoblastoma.
The patient in this vignette has a high-risk histopathology in the enucleated eye (scleral invasion), which means he has an increased risk for the presence of metastatic disease. This must be fully evaluated with bilateral bone marrow aspirates/biopsies (BMA/BX) and CSF analysis.
If he has no metastatic disease, then he should be treated as stage 2 with 4-drug adjuvant chemotherapy (systemic) with radiation.
The presence of metastatic disease in the bone marrow or CSF indicates stage 4a or 4b, respectively, and requires chemotherapy, consolidation with high-dose chemotherapy and autologous stem cell rescue, and radiation therapy. .
