Abdominal masses (Neuroblastoma, Wilms, Hepatoblastoma, Rhabdomyosarcoma)

#1 most common abdominal malignancy: Neuroblastoma

#2 Wilms tumor

#3 Hepatoblastoma

(Most common abdominal tumors in teens: NHL, Rhabdo, germ cell tumors)

Other malignant abdominal masses include:

• hepatocellular carcinoma
• teratocarcinoma
• adrenal carcinoma
• Rhabdomyosarcoma usually presents in the pelvis, involving the bladder, uterus, vagina, or testes; less frequently it appears as a diffuse retroperitoneal mass. It does not involve the adrenal gland.

Most abdominal masses are not malignant.

• The most common renal mass is congenital hydronephrosis, and Multicystic-Dysplastic Kidney also is frequent.
• Choledochal cysts
• bezoars
• gastrointestinal duplications
• polyps

Ultrasonography readily differentiates most of these benign masses from malignant ones and is the initial imaging study of  choice in children who have abdominal masses.

References:
Anveden-Hertzberg L, Gauderer MW. Abdominal masses. In: Kliegman RM,
Nieder ML, Super DM, eds. Practical Strategies in Pediatric Diagnosis
and Therapy. Philadelphia, Pa: WB Saunders Co; 1996:387-399
Brodeur GM, Castleberry RP. Neuroblastoma. In: Pizzo PA, Poplack DG,
eds. Principles and Practice of Pediatric Oncology. 3rd ed.
Philadelphia, Pa: Lippincott-Raven; 1997:761-797
Castleberry RP. Biology and treatment of neuroblastoma. Pediatr Clin
North Am. 1997;44:919-937