and Mhamed Harif2
(1)
South African Medical Research Council, Cape Town, South Africa
(2)
Université Mohammed VI des Sciences de la Santé Cheikh Khalifa Hospital, Casablanca, Morocco
Keywords
Kidney tumorAbdominal mass or distentionAbdominal ultrasoundChemotherapyStagingSurgeryLungmetastasesGood prognosisYounger childrenHypertensionCase Presentation
A 2-year old presented to the hospital with a 2-week history of abdominal distension and palpable right flank mass. Informal ultrasound at a peripheral hospital demonstrated a solid mass in the right flank of unknown origin.
No previous medical history of note (Fig. 8.1).
Fig. 8.1
Initial presentation abdominal distension; flank mass delineated by a marker
Findings on Examination
Not acutely ill
W = 9 kg, H = 84 cm
Observations: BP 101/58 mmHg, rest normal Urine Dipsticks: NAD
No pallor. No lymphadenopathy
Cardiovascular, respiratory and central nervous system: Normal examination
Abdominal examination: Distended. Right flank mass extending to the liver edge, not crossing the midline
What Is the Differential Diagnosis?
Abdominal masses : lymphoma, neuroblastoma, hepatoblastoma.
Benign renal conditions : hydronephrosis, cystic renal dysplasia, mesoblastic nephroma, xanthogranulomatous pyelonephritis.
Less common renal tumors : clear cell sarcoma of the kidney, rhabdoid tumor, mesoblastic nephroma, renal cell carcinoma.
What Investigations Would You Like to Request?
CBC, renal function.
Abdominal ultrasound .
Chest X-ray (PA view and lateral view).
CT scan abdomen.
Herein listed are available results for your case scenario:
Wcc | Hb | Mcv | Plt | N | L | Na | K | Ur | Cr |
|---|---|---|---|---|---|---|---|---|---|
11.1 | 8.6 | 85 | 269 | 5.5 | 4.1 | 139 | 5 | 3.5 | 24 |
A large, capsulated, well-circumscribed, heterogeneous solid mass containing some well-defined cystic areas of various sizes is noted measuring approximately 11.3 × 9.3 × 16.9 cm and which appears to originate from the lower pole of the right kidney (Figs. 8.2, 8.3, 8.4, 8.5, and 8.6).
Fig. 8.2
Ultrasound abdomen
Fig. 8.3
Chest X-ray : AP
Fig. 8.4
CT scan abdomen (not required if not affordable)
Fig. 8.5
MRI abdomen (not required)
Fig. 8.6
CT chest (not required)
There is a large mixed solid cystic heterogeneous mass arising from the lower pole right kidney which measures 14.5 × 11.5 cm. The tumor also compresses and displaces the IVC.
The marked atelectasis may relate to elevation of the left and right hemidiaphragm in a patient with a large intra-abdominal mass lesion. No pulmonary metastatic lesions seen.
Histological Diagnosis: made by histopathological examination of tissue obtained during surgical resection (Fig. 8.7).
Fig. 8.7
Excised tumor specimen
Epidemiology
Nephroblastoma or Wilms tumor (WT) is the most common renal malignancy in children.
It represents 5–10 % of childhood cancers and its annual incidence is about eight new cases per million children under 15 years.
More than 2/3 of the cases occur in children under the age of 5 years and 95 % in patients occur under the age of 10 years.
Girls are more affected than boys and in 5–10 % of cases both kidneys can be affected simultaneously. Asynchronous involvement is also possible. The modern multidisciplinary approach will cure more than 90 % of patients.
In Africa
Nephroblastoma remains one of the most common solid tumors in Africa exceeding 10 % of total pediatric cancers in many countries (Rwanda 26.0 %, Senegal 22 %, Ivory Coast 14.5 %, Mali 17.6 %, Congo 15.5 %).
Associated Genetic Abnormalities
The WT1 gene plays an important role in the development of the kidney and gonads . A deletion or mutation of the 11p13 region involving the WT1 gene can be detected in tumor cells in less than 10 % of the sporadic forms.
The abnormalities may be isolated or part of a syndrome predisposing to the occurrence of Wilms tumor. Isolated anomalies are essentially genitourinary resulting in a duplication of the urinary tract, a horseshoe kidney, hypospadias, or cryptorchidism. The hemi-body hypertrophy and Wilms tumor have been described. Aniridia is also associated with Wilms tumor and may occur together with genitourinary anomalies and mental retardation (WAGR syndrome). In Denys–Drash a mutation of WT1 is found leading to nephrotic syndrome before developing Wilms tumor. Loss of imprinting (LOI) of 11p15 is found in the Beckwith–Wiedemann syndrome. One percent of Wilms tumors are familial with different known genetic anomalities.
Clinical Presentation
The finding of an abdominal mass by parents or during a consultation for fever or digestive disorders is the most common mode of presentation. The abdominal tumor is located anteriorly and is mobile, painless ,and ballotable (Fig. 8.8). It can be associated with abdominal pain if it becomes voluminous and should raise the suspicion of intratumoral hemorrhage if trauma is involved.
