What are 16 entities in the differential diagnosis of an abdominal mass in a neonate?

Renal causes
1. Hydronephrosis (most common)
2. Multicystic dysplastic kidney
3. Infantile polycystic kidney disease
4. Mesoblastic nephroma

Genital causes
5. Ovarian cyst (result of stimulation by maternal hormones)
6. Hydrometrocolpos

Gastrointestinal causes
7. Enteric duplication or mesenteric cyst
8. Dilated bowel proximal to obstruction or atresia
9. Volvulus
10.Meconium ileus

Retroperitoneal causes
11. Adrenal hemorrhage
12. Teratoma
13. Neuroblastoma

Hepatobiliary causes
14. Hepatoblastoma
15. Hemangioma or hemangioendothelioma
16. Choledochal cyst