Diagnosis of Wilms tumor

The volume of necessary studies for suspected Wilms tumor

Anamnesis	Family oncological anamnesis, congenital defects
Medical checkup	Identification of congenital anomalies (aniridia, hemihypertrophy, urogenital anomalies), measurement of blood pressure
General blood analysis	The presence or absence of polycythemia
General urine analysis	The presence or absence of microhematuria
Blood chemistry	The concentration of urea, creatinine, uric acid, glutam-noxaloacetate kinase, glutamine pyruvate kinase, lactate dehydrogenase and alkaline phosphatase in serum
Evaluation of hemostasis	Prothrombin time, thromboplastin time, fibrinogen concentration, bleeding time (if increased, determine the concentration of factor VIII, von Willebrand factor antigen)
Evaluation of cardiac activity	Electrocardiography and echocardiography are shown to all patients receiving anthracyclines (echocardiography, in addition, allows to identify a tumor thrombus in the right atrium)
Ultrasound examination of abdominal organs	-
CT of abdominal organs with targeted examination	Allows you to clarify the presence and function of the contralateral kidney, exclude bilateral renal involvement, involvement of the major vessels and lymph nodes in the tumor process, determine tumor liver infiltration
Radiography of the thoracic cavity organs (in three projections)	-
CT of thoracic cavity organs	It allows to identify small metastases that can be hidden by ribs or diaphragm and are missed by radiographic examination of the thoracic cavity organs
Radioisotopic examination of the skeleton	The study is shown only in the case of a clear cell renal sarcoma that can metastasize to the bone
CT or MRI of the brain	The study is shown in the case of rhabdomous tumors, often associated with CNS tumors, and a clear celled sarcoma of the kidney that can metastasize to the brain
Chromosomal analysis of peripheral blood cells	The study is shown with congenital anomalies (aniridia, Bekuit-Wiedemann syndrome, hemihypertrophy)

At the preoperative stage, it is necessary to investigate the function of the unbounded contralateral kidney, exclude metastases in the lungs, and the presence of tumor thrombi in the inferior vena cava.

Staging of Wilms tumor

Clinical and pathological staging of Wilms tumor

Stage	Characteristics of the tumor
I	The tumor is bounded by the kidney and completely removed, the renal capsule is intact. Tumor rupture before surgery and during removal there. The tumor is removed radically, the tumor tissue is not marginalized
II	The tumor sprouts the capsule of the kidney, but is completely removed, the regional spread of the tumor is revealed (that is, the germination of the tumor into the soft tissues surrounding the kidney). Ureters are not involved in the tumor process, there is no invasion of the renal pelvis. After surgery, there are no signs of a tumor
III	Restricted abdominal cavity residual tumor without hematogenous metastases, as well as the presence of any of the following factors. A. Morphologically confirmed involvement of lymph nodes outside the para-aortic zone in the tumor process . B. Diffuse peritoneal contamination with tumor cells with ipsilateral therapy before or during surgery or with the spread of tumor cells through the peritoneum due to rupture of the tumor before or during surgery. B. Peritoneal tumor implants. G. Post-operatively macroscopically or microscopically determine the residual tumor. D. Tumor is not completely removed due to infiltration of vital structures
IV	Hematogenous metastases: metastases to the lungs, liver, bones, brain
V	Bilateral tumors at the time of diagnosis: a study is required on each side, according to the criteria for diagnosis at the preoperative stage. This stage is divided into a number of sub-stages. A. The defeat of one of the poles of both kidneys. B. The defeat of one kidney with involvement of the organ organ (total or subtotal) in the tumor process and one of the poles of the second kidney. C. The defeat of both kidneys with the involvement of the gates (total or subtotal)

Pathomorphological characteristics of Wilms tumor

The Wilms tumor is derived from the cells of a primitive metanephric blastema and is characterized by a variety of histological pattern. The classical variant of the Wilms tumor is represented by blastema cells and dysplastic epithelial tubules, contains a mesenchyme or stroma. Determination of epithelial germ cells and stromal cells in tumor tissue led to the appearance of the term "three-phase histological picture", characterizing the classical variant of the Wilms tumor. Each type of Wilms tumor cell can differentiate in different directions, repeating the stages of renal embryogenesis. The ratio of cellular types in tumor tissue in different patients may differ significantly.

It should be noted that light-cell renal sarcoma and rhabdomous kidney tumor are not variants of Wilms tumor.

Wilms' anaplastic tumor

The presence of cell anaplasia in Wilms' tumor is the only criterion of an "unfavorable" histological picture. Focal anaplasia from diffuse differs from the degree of distribution in the tumor tissue. In the first case, anaplastic nuclei are focally limited to one or more sites without anaplasia. To establish the morphological diagnosis of diffuse anaplasia, anaplastic cells in any extrarenal localization (ureters, extracapsular infiltrate, regional or distant metastases), anaplasia in the tumor biopsy (more than one section) are necessary.

[1], [2], [3], [4]