A 2-year-old girl is brought to the pediatrician after her parents noticed a “white reflection” in her left eye in several photographs. There is no history of trauma to the eye or eye infection. She was born at term and has no significant past medical history. On physical examination, the red reflex is absent in the left eye but present in the right. The child does not track objects well with the left eye.
Which of the following is the most likely diagnosis?
The correct answer is:
C) Retinoblastoma
Leukocoria (white pupillary reflex) in a young child is a classic presenting sign of retinoblastoma, the most common primary intraocular malignancy in children. It results from malignant retinal tumors reflecting light rather than producing a normal red reflex. Retinoblastoma often presents before age 3 years and may also cause strabismus or decreased visual tracking. Early recognition is critical, as the disease can be life-threatening if it spreads beyond the eye.
Answer choice A: Congenital cataract, is incorrect. Congenital cataracts can cause leukocoria but are typically present at birth or detected in early infancy and involve lens opacity rather than retinal pathology.
Answer choice B: Persistent hyperplastic primary vitreous, is incorrect. Persistent hyperplastic primary vitreous is a rare congenital eye development disorder where embryonic hyaloid blood vessels fail to regress. This condition presents at birth with leukocoria and is associated with microphthalmia, which is not described in this vignette.
Answer choice D: Retinopathy of prematurity, is incorrect. Retinopathy of prematurity occurs in premature infants with a history of oxygen therapy, which is absent in this case.
Answer choice E: Toxocariasis, is incorrect. Ocular toxocariasis can cause leukocoria but is usually associated with a history of exposure to dogs or contaminated soil and presents later in childhood.
Key Learning Point
Leukocoria in a young child is retinoblastoma until proven otherwise and requires urgent ophthalmologic evaluation due to its potential lethality.
