Neonatal Nurse Practitioner Practice Exam

In a two-day-old neonate with an abdominal mass, what is the most likely cause?

1. Adrenal hemorrhage

2. Polycystic kidney

3. Volvulus

4. Hernia

The correct answer is: Polycystic kidney

In a two-day-old neonate presenting with an abdominal mass, the most likely cause is polycystic kidney disease. This condition is characterized by the development of numerous fluid-filled cysts within the kidneys, which can often present as a palpable mass in the abdomen of neonates shortly after birth. Polycystic kidney disease is a genetic disorder that can be inherited in different forms, but its manifestation in neonates is often associated with significant renal enlargement and complications such as hypertension or renal failure. This condition is particularly significant in the perinatal period as imaging studies, such as an ultrasound, would typically reveal enlarged kidneys with cystic changes. While adrenal hemorrhage, volvulus, and hernias can also present with abdominal masses in neonates, they have different clinical characteristics or presentations that may not align with the age of the neonate in this situation. Adrenal hemorrhage usually presents with signs of stress, jaundice, or hypotension, and it often occurs due to birth trauma. Volvulus typically manifests with signs of acute bowel obstruction, such as bilious vomiting, which is not immediately apparent in a two-day-old without further symptoms. A hernia, while capable of causing a palpable mass, is often associated with visible