Paediatrics: Abdominal/renal mass

Abdominal/renal mass

A rare presentation of urinary tract problems, which needs to be differentiated from other causes of abdominal mass and swelling.

Causes

Intrarenal

• Wilms’ tumour (young child with rapidly growing mass).
• Renal venous thrombosis (newborn with haematuria).
• Benign nephroma (rare neonatal problem).
• Horseshoe kidney.
• Pyelonephritis (renal abscess).

Other renal

Hydronephrosis associated with the following.

• Pelviureteric junction (PUJ) obstruction.
• Vescioureteric junction (VUJ) obstruction.
• Large bladder and bladder outlet obstruction: e.g.

o posterior urethral valves (PUV);

o prune belly syndrome;

o neurogenic bladder.

• Urinoma: i.e. an encapsulated extra pelvicalyceal collection of urine that forms from urine leakage through a tear in the collecting system or the proximal ureter.
• A single cyst (benign renal cyst).
• Multicystic dysplastic kidney—usually newborn.
• Polycystic disease:

o autosomal recessive;

o autosomal dominant—rare in children.

• Haematoma (trauma).

Extrarenal

Adrenal mass (e.g. neuroblastoma).

Investigation

• US will distinguish between most of the above.
• Further investigation, depending on likely causes and discussion with radiology and urology colleagues, e.g. CT, MRI.