<prompt> Which is the commonest abdominal mass in neonate :Wilms tumorPolycystic kidneyNeuroblastomaRhabdomyosarcoma  <response>: The commonest intra - abdominal tumor in first two years of life Neuroblastoma.The commonest intra - abdominal tumor between 2nd to 5th year of life Wilms tumor.The commonest intro - abdominal tumor in children no age specification Neuroblastoma.Wilms tumor is the second most common abdominal tumor in children.Remember: The commonest cause of abdominal mass in Newborn is Multiple dysplastic kidneys if neoplasm or tumor has not been mentioned when asking for the commonest intra-abdominal mass, the answer will be multiple dysplastic kidneys. 