Nephroblastoma – Wilms tumor
Wilms tumor, nephroblastoma is a malignant renal tumor of children, with a peak of morbidity at three years. It affects both sexes equally. It is usually unilateral, but in a minority of cases (5%) may be located bilateral (affecting both kidneys). It can be accompanied by a number of genito-urinary abnormalities such as cryptorchidism (malformation consisting of incomplete migration of the testicle, which is outside the scrotum, in a point on the track of normal descent), hypospadias (congenital malformation that characterized by the opening of the urethra, the urinary meatus on the underside of the penis) or horseshoe kidney.
From etiological point of view there are two forms: a sporadic form and a familial form (20%).
In terms of anatomical pathology, macroscopic, nephroblastoma is a large, gray tumor with multilobules, with areas of hemorrhage and necrosis.
Tumor dissemination can be done by local extension through the renal capsule, either by venous (through renal and cava veins) or lymph nodes. The organs most commonly affected by metastases are the lungs and liver.
Nephroblastoma, it gives no very noisy symptoms, this may delay diagnosis and treatment.
The most common sign is the appearance of an abdominal tumor, which may be detected incidentally by family or physician by palpation (bulky tumor, smooth or slightly irregular, mobile and painless). This tumor may be accompanied by hypertension, abdominal pain, nausea, vomiting, fever and hematuria (blood in urine).
To confirm the diagnosis of nephroblastoma clinical aspects should be correlated with laboratory investigations.
– Laboratory tests – urine tests (which may reveal hematuria)
– Blood count (may reveal anemia because these patients may have persistent hematuria);
– Ultrasound, computed tomography and magnetic resonance image – confirm tumor in the kidney;
– Radiological exploration – shows increased renal shadow and distortion of pielo-pelvis system;
– Selective arteriography – is used only in cases where the tumor is located bilaterally;
– Chest x-ray and liver ultrasound – for evidence of possible metastasis.
Treatment of nephroblastoma is a surgery intervention that must respect the principles of oncology, practicing the median laparotomy (abdominal incision) with nephrectomy (surgical removal of kidney) and extended lymphadenectomy (removal of lymph nodes).
Nephroblastoma is a radiosensitive tumor and responds favorably to chemotherapy (Actinomicin, vincristine, doxorubicin, cisplatin).
Treatment should be individualized according to disease stage.
Nephroblastoma has a high cure rate therefore is important to establish a proper treatment as early as possible.