Wilms tumour and renal malignancies: SAQ

This girl has the classic presentation of a Wilms tumour: the painless abdominal mass found by the parent at the bath time, the smooth firm flank mass that does not cross the midline, and the hypertension that accompanies the renal tumour. The task is to reach the imaging, to stage the tumour, and to build the risk-adapted definitive therapy in the specialist centre, while holding the high cure rate of the favourable-histology disease against the worse prognosis of the higher stage and the unfavourable histology. ^[1]

Question 1 (10 marks)

Outline your immediate diagnostic pathway for this three-year-old girl with the flank mass and the hypertension. ^[1]

A full-mark answer covers the recognition of the renal tumour, the first-line imaging with the Doppler of the cava, the cross-sectional imaging and the staging, and the avoidance of the biopsy in the typical case, with the referral to the specialist centre. ^[4]

Recognition and the first decision (2 marks). The painless abdominal mass that does not cross the midline, with the hypertension, declares a renal tumour until the imaging settles it, and the Wilms tumour is the working diagnosis. The first priority is the imaging that confirms the renal origin and excludes the tumour thrombus, and the avoidance of the biopsy that would upstage the tumour. ^[1]

First-line imaging (3 marks). The abdominal ultrasound with the Doppler of the renal vein and the inferior vena cava is the first test, because it confirms the renal origin, shows the solid character of the mass, and defines the tumour thrombus that changes the surgical plan. The hypertension is controlled with the careful titration of the antihypertensive, and the child is kept calm and pain-free. ^[9]

Cross-sectional imaging and the staging (3 marks). The computed tomography or the magnetic resonance imaging of the abdomen defines the size, the local extension and the contralateral kidney, and the chest computed tomography is performed in every child because the lung is the commonest site of the metastasis. The bone scan and the brain magnetic resonance imaging are added for the clear cell sarcoma and the malignant rhabdoid tumour, which metastasise to the bone and the brain. ^[4][9]

Avoidance of the biopsy and the referral (2 marks). In the Children's Oncology Group approach, the radiologically typical tumour proceeds directly to the radical nephrectomy with the lymph node sampling, and the biopsy is avoided because the spill upstages the tumour to the stage three and commits the child to the radiotherapy. The child is referred to the specialist paediatric oncology centre, and the stigmata of the Beckwith-Wiedemann, the WAGR and the hemihypertrophy are sought for the syndromic counselling. ^[4][6]