In simple words: This code describes a condition where a baby is born with one or both kidneys larger than normal.This happens because the kidney cells are either more numerous or larger than usual, often to compensate for problems with the other kidney.

Q63.3, Hyperplastic and giant kidney, refers to the condition where one or both kidneys are abnormally large due to hyperplasia (increased cell number) or compensatory hypertrophy (increased cell size in response to loss of function in the other kidney).This is a congenital condition, meaning it is present at birth.The increased size may be due to various underlying causes affecting kidney development. It is important to differentiate this from acquired conditions leading to kidney enlargement.

Example 1: A newborn infant is diagnosed with a unilateral hyperplastic kidney during a routine ultrasound. The contralateral kidney is normal. , A child with a history of unilateral renal agenesis (absence of one kidney) presents with a significantly enlarged contralateral kidney, showing signs of compensatory hypertrophy., A fetus is found to have bilateral hyperplastic kidneys during a prenatal ultrasound scan. Further investigation reveals no other renal anomalies.

Prenatal ultrasound findings (if applicable), postnatal ultrasound or imaging studies (e.g., CT scan, MRI) demonstrating kidney size and morphology, laboratory results including renal function tests (e.g., creatinine, GFR), and any genetic testing performed to identify possible underlying causes. Comprehensive family history should also be documented.

** The size of the kidney relative to the patient's age and body size is crucial for diagnosis.Further investigations may be necessary to identify associated conditions or genetic predispositions.