During a routine examination of a 3-year-old child, the pediatrician notes that the color of the pupil is white and that the child is cross-eyed. She asks the child's father if there are any cases of retinoblastoma in the family, and when the answer is in the affirmative she calls in a pediatric ophthalmologist. The ophthalmologist knows that retinoblastoma is due to the mutation of the Rb gene (retinoblastoma gene) and that it is a recessive trait. Retinoblastoma can metastasize to the brain via the
A) optic nerve
B) superior division of the oculomotor nerve
C) trochlear nerve
D) abducent nerve
E) inferior division of the oculomotor nerve

Question

Quizplus · Accepted Answer

Retinoblastoma can metastasize to the brain via the optic nerve, which connects the eye to the brain. The Rb gene mutation causes uncontrolled cell growth in the retina, leading to the development of retinoblastoma. If left untreated, the cancer can spread to other parts of the body, including the brain. Cross-eyedness and the appearance of a white pupil are both common signs of retinoblastoma, and a family history of the disease can increase the risk of developing it.

During a Routine Examination of a 3-Year-Old Child, the Pediatrician