18/10/2025
Retinoblastoma — The Most Common Intraocular Malignancy in Children
Retinoblastoma is a malignant tumor of the retina arising from the retinoblast (embryonic retinal cell) due to mutations.
It is life-threatening, but highly curable when detected early.
EPIDEMIOLOGY:
Most common intraocular malignancy of childhood.
Usually diagnosed before 5 years of age.
Can be hereditary (40%) or sporadic (60%).
Bilateral in hereditary cases; unilateral in sporadic cases.
PATHOPHYSIOLOGY:
RB1 gene mutation leads to loss of tumor suppression.
Hereditary form: Germline mutation → predisposes to multiple, bilateral tumors and secondary cancers (osteosarcoma).
Sporadic form: Somatic mutation → single, unilateral tumor.
CLINICAL FEATURES:
Leukocoria (white pupillary reflex) — most common presenting sign.
Strabismus (due to macular involvement).
Diminished vision.
Pain, redness, or secondary glaucoma in advanced stages.
Rarely, orbital inflammation or proptosis if extraocular spread occurs.
DIAGNOSTIC FINDINGS:
Fundus Examination: Creamy-white retinal mass, often with calcification and overlying vessels.
Ultrasound (B-scan): Highly reflective intraocular mass with calcifications.
CT / MRI: Used to detect calcification, optic nerve invasion, or extraocular spread.
Genetic testing for RB1 mutation in bilateral or family cases.
Types (Based on Growth Pattern)
Endophytic: Grows into the vitreous → causes vitreous seeding.
Exophytic: Grows under retina → causes retinal detachment.
Diffuse infiltrating: Rare, flat infiltrative pattern.
MANAGEMENT:
Depends on tumor size, location, and extent of spread:
Focal therapy:
Laser photocoagulation
Cryotherapy
Thermotherapy
Chemoreduction: Systemic or intra-arterial chemotherapy to shrink tumors.
Enucleation: For advanced, unilateral cases with no visual potential.
External beam radiotherapy: Reserved for resistant or recurrent cases.
Genetic counseling for families of hereditary cases.
COMPLICATIONS:
Optic nerve invasion
Orbital extension
Metastasis to brain or bone marrow
Secondary malignancies (in hereditary cases after radiation)
Key Takeaway
Retinoblastoma = Life + Vision emergency.
Early detection and multidisciplinary management can ensure over 95% survival and preserve useful vision in many cases.
Photo: Pulse
