Retinoblastoma

Question 1

What is the presentation of retinoblastoma?

Answer 1

• Leukocoria (white pupillary reflex) is commonest presentation (60%) & may 1st be noticed in family photos
• Strabismus is 2nd most common (20%) – fundus examination is therefore mandatory in all cases of childhood squint
• Painful red eye w/ secondary glaucoma – may occasionally be associated w/ buphthalmos (enlarged eyes commonly due to glaucoma)
• Poor vision
• Inflammation or pseudoinflammation

Question 2

What age does retinoblastoma typically present (unilateral and bilateral)?

Answer 2

Within 1st year of life in bilateral cases
Around 2 years of age if tumour is unilateral

Question 3

What is it important to ask about in family history?

Answer 3

Careful enquiry about a family history of ocular tumours is critical

Question 4

What are the common signs of retinoblastoma?

Answer 4

• Intraretinal tumour is homogenous, dome-shaped white lesion that becomes irregular, often w/ white flecks of calcification
• An endophytic tumour projects into vitreous as white mass that may ‘seed’ into the gel
• An exophytic tumour forms multiobular subretinal white masses & causes overlying retinal detachment

Question 5

What are common investigations you would carry out for retinoblatoma?

Answer 5

• Red reflex testing – w/ direct ophthalmoscope – simple screening test for leukocoria
• Examination under anaesthesia – tonometry, measurement of corneal diameter, general examination for congenital abnormalities of face & hands

Question 6

What are the differential diagnoses for retinoblastoma?

Answer 6

• Coats disease – always unilateral, more common in boys, tends to present later
• Retinopathy of prematurity – may cause RD & leukocoria if advanced, hx of prematurity & low birth weight
• Uveitis – may mimic diffuse infiltrating type of retinoblastoma seen in older children – retinoblastoma may be mistaken for uveitis, endophthalmitis or orbital cellulitis

Question 7

What other things may occur in retinoblastoma that could be confused with other conditions?

Answer 7

• Routine exam of px known to be at risk
• Orbital inflammation mimicking orbital or preseptal cellulitis may occur w/ necrotic tumours
• Orbital invasion or visible extraocular growth may occur in neglected cases
• Metastatic disease involving regional lymph nodes & brain before detection of ocular involvement is rare