Work-up & Staging Flashcards
What is the DDx for pts who present with leukocoria?
Toxocariasis, hyperplastic primary vitreous, Coat Dz, retrolental fibrodysplasia, congenital cataracts, and toxoplasmosis
Is Bx done for RB?
Generally not. B/c of the fear of seeding, the Dx is established clinically.
What is the typical workup for pts with an intraocular mass?
Intraocular mass workup: H&P (EUA, max dilated pupil, scleral indentation, ocular US), labs, US/CT, MRI of brain and orbits (most sensitive to evaluate extraocular extension)
When are bone scan, BM Bx, and LP indicated?
If the tumor is not confined to the globe (with deep invasion), BM Bx, LP, and bone scan are indicated.
What % of RBs are calcified?
90% of RBs are calcified.
What staging systems are used for RB?
The International Classification for Intraocular Retinoblastoma is used for staging in COG protocols. Reese–Ellsworth grouping system predicts for visual preservation after EBRT but does notpredict for survival and is therefore being phased out. The AJCC 8th edition now incorporates Dz extent with germline cancer predisposition.
Summarize the International Classification for Intraocular Retinoblastoma
Group A (Very Low Risk): all tumors ≤3 mm in thickness, confined to retina, and >3 mm from foveola and >1.5 mm from optic disc
Group B (Low Risk): all tumors confined to retina, clear subretinal fluid ≤3 mm from tumor with no subretinal seeding
Group C (Moderate Risk): discrete tumors, subretinal fluid without seeding involving up to one-fourth of retina, local fine vitreous seeding close to discrete tumor, local subretinal seeding ≤3 mm from tumor
Group D (High Risk): massive or diffuse tumors; subretinal fluid or diffuse vitreous seeding; retinal detachment; diffuse or massive Dz including greasy seeds or avascular tumor masses; subretinal seeding may include subretinal plaques or tumor nodules
Group E (Very High Risk): presence of any of the following features: invasion of postlaminar optic nerve, choroid (>2 mm), sclera, orbit, ant chamber; tumor ant to ant vitreous surface involving ciliary body or iris; diffuse infiltrating RB; neovascular glaucoma; opaque media from hemorrhage in ant chamber, vitreous, or subretinal space; tumor necrosis with aseptic orbital cellulites; phthisis bulbi (shrunken, nonfunctional eye)
Summarize the AJCC 8th edition clinical staging for RB.
cT0: No evidence of intraocular tumor
cT1: Intraretinal tumor(s) with subretinal fluid ≤5 mm from the base of tumor
cT1a: Tumors ≤3 mm and >1.5 mm from disc and fovea
cT1b: Tumors >3 mm or <1.5 mm from disc or fovea
cT2: Intraocular tumor(s) with retinal detachment, vitreous seeding, or subretinal seeding
cT2a: Subretinal fluid >5 mm from base of tumor
cT2b: Vitreous seeding and/or subretinal seeding
cT3: Advanced intraocular tumor(s)
cT3a: Phthisis or prephthisis bulbi
cT3b: Tumor invasion of choroid, pars plana, ciliary body, lens, zonules, iris, or ant chamber
cT3c: Raised intraocular pressure with neovascularization and/or buphthalmos
cT3d: Hyphema and/or massive vitreous hemorrhage
cT3e: Aseptic orbital cellulitis
cT4: Extraocular tumor(s) involving orbits, including optic nerve
cT4a: Radiologic evidence of retrobulbar optic nerve involvement or thickening of optic nerve or involvement of orbital tissues
cT4b: Extraocular tumor clinically evident with proptosis and/or an orbital mass
cN0: No regional LN involvement
cN1: Evidence of preauricular, submandibular, and cervical LN involvement
cM0: No signs or Sx of intracranial or distant mets
cM1: DM without microscopic confirmation
cM1a: Tumor(s) involving any distant site (e.g., BM, liver) on clinical or radiologic tests
cM1b: Tumor involving the CNS on radiologic imaging (not including trilat RB)
H0: Normal RB1 alleles in blood tested with demonstrated high-sensitivity assays
H1: Bilat RB, RB with an intracranial PNET, Pt with FHx of RB, or molecular definition of a constitutional RB1 gene mutation
