Kidney Cancer - Symptoms and Diagnosis

Symptoms of kidney cancer

Clinical symptoms of kidney cancer are varied. The triad of symptoms - hematuria, swelling and pain - occurs at an advanced stage of the disease. Much more often, the disease is asymptomatic and is diagnosed by chance when the patient visits a doctor for another reason or during a medical examination, sometimes it manifests itself with one or two symptoms from the triad.

One of the most common symptoms of kidney cancer is total hematuria. This symptom occurs in 60-88% of patients. The mechanism of hematuria in kidney tumors has not been fully elucidated. The most common opinion is that intense hematuria is a consequence of the destruction of blood vessels by the tumor. And the occurrence of hematuria in kidney cancer that does not communicate with the pelvis is explained by a disorder of hemodynamics in the kidney.

Hematuria in tumors has a number of specific features. It is always total, appears suddenly, often in the midst of complete health or against the background of more or less intense pain in the kidney area. Sometimes, following hematuria, a typical attack of renal colic develops, which is relieved after the passage of clots. The occurrence of acute pain following intense hematuria is typical for kidney tumors. In other diseases, also accompanied by hematuria (renal stone disease, nephroptosis, hydronephrosis), pain usually precedes hematuria. In addition, bleeding in these diseases is rarely intense and is usually not accompanied by the passage of clots.

Hematuria may appear during a single urination or may continue for several hours or days and then suddenly disappear. The next bleeding may occur in a few days, or sometimes in a few months or even years.

The periods between repeated hematuria tend to be shorter. Since hematuria in kidney cancer is often profuse, it is often accompanied by the passage of blood clots in the urine. Quite often, hematuria is the only symptom that is not accompanied by pain or dysuria, unless the latter is caused by the accumulation of blood clots in the bladder. Acute urinary retention may develop due to tamponade of the bladder by clots, which is eliminated after spontaneous passage or evacuation of the clots.

Thus, the characteristic features of hematuria in kidney cancer are sudden onset, profuseness, the presence of clots, intermittent nature, and often painless course.

Pain is the second most common symptom of kidney cancer. According to various authors, the pain symptom occurs in 50% of patients. The pain can be dull and sharp, constant and paroxysmal. Dull pain can be a consequence of stretching or ingrowth of the fibrous capsule of the kidney, rich in nerve endings, pressure of the growing tumor node on neighboring organs, nerve trunks or lumbar roots. Dull pain can also be caused by displacement and tension of the vessels of the renal pedicle.

Acute pain may occur as a result of a sudden increase in intrarenal pressure due to blockage of the renal pelvis or ureter by blood clots. Hemorrhages into the renal parenchyma or tumor tissue may also be the cause of acute pain.

The third symptom of kidney cancer is a palpable tumor. This symptom is currently rare, due to the fact that small kidney cancers are diagnosed by ultrasound. It should be noted that it is not always possible to determine the tumor by palpation. The least accessible for palpation tumors are the upper pole of the kidney, in which it is often possible to palpate the unchanged lower pole as a result of the downward displacement of the kidney.

There is no parallelism between the size of kidney cancer and the stage of the process. There may be distant metastases with a diameter of the primary tumor node of no more than 2 - 3 cm.

Kidney cancer is often accompanied by symptoms that are not of a "urological" nature, these are paraneoplastic symptoms. They can precede the classic signs of kidney cancer by several months, and sometimes years.

Among these symptoms, fever takes the leading place if it is the only symptom of the disease. An increase in body temperature in kidney tumors can be observed both in the initial and in advanced stages of the disease. In the presence of necrotic and inflammatory processes in the tumor, an increase in temperature can be explained by the absorption of the decay products of kidney cancer, etc. In the initial stages, high temperature is either a consequence of intoxication or the result of a pyrogenic reaction to a foreign protein.

The nature of fever in kidney cancer varies, but it is most often constant or intermittent. In connection with such a temperature, the patient is usually looked for a purulent focus, subjected to numerous studies and antibacterial therapy. And only when hematuria or other symptoms of kidney cancer occur against the background of a long-term fever, the patient is referred to a urologist.

The most common symptom that accompanies fever in kidney tumors is an elevated ESR. This may be the only sign of a kidney tumor, and therefore patients are also subject to urological examination.

One of the very peculiar manifestations of the tumor process in the kidney is renal polycythemia - secondary erythrocytosis. Most often, the cause of erythrocytosis is clear cell cancer.

Secondary erythrocytosis is described not only in malignant but also in benign tumors and kidney cysts, hydronephrosis, and renal artery stenosis. The cause of the increase in the amount of hemoglobin and erythrocytes in kidney diseases is reactive, functional irritation of erythropoiesis. It is known that erythrocytosis develops due to increased production of erythropoietin by a tumor or kidney parenchyma.

The persistent disappearance of erythrocytosis after renal cancer removal is a favorable prognostic sign. At the same time, the resumption of this symptom indicates either a relapse or metastasis of the tumor.

Kidney cancer may be accompanied by arterial hypertension, according to A. Ya. Pytel (1966), in 15-20% of cases. The mechanism of hypertension in kidney tumors remains unclear. Some authors attach importance to endocrine disorders in the genesis of hypertension, others - to the influence of sclerotic changes in blood vessels, the location of the tumor near the renal hilum, and indicate the possibility of the tumor producing a vasopressive substance, as evidenced by the normalization of pressure after tumor removal.

Kidney cancer is sometimes accompanied by hypercalcemia, which may be the only symptom of the disease, disappears after radical nephrectomy and may reappear with metastasis or tumor recurrence.

Immunological studies of tumor tissue from patients with renal adenocarcinoma and hypercalcemia have found substances inside the tumor that are not antigenically different from parathyroid hormone. Kidney cancer accompanied by hypercalcemia progresses rapidly and, as a rule, has a poor prognosis.

Sometimes the first symptom of kidney cancer is distant metastases (in the lung, bones, brain, etc.). It should be noted that most often metastases as the first clinical manifestations of the disease are localized in the skeletal system and lungs.

Sometimes a kidney tumor first manifests itself with “uncharacteristic” metastases to organs such as the mammary gland, the wall of the urinary bladder, the wall of the ureter, the larynx, the thyroid gland, the external auditory canal, the heart muscle, the frontal bone, the wall of the vagina, etc.

One of the important symptoms of kidney tumors is varicocele. It may be caused by the following reasons in kidney cancer: compression or invasion of the renal vein by the tumor; compression of the inferior vena cava or directly one of the testicular veins by the tumor or metastatic nodes; thrombosis of the inferior vena cava; kink of the renal vein as a result of the kidney being displaced downwards; tumor thrombus in the renal vein. Under these conditions, the pressure in the renal or inferior vena cava increases, and collateral and venous outflow occurs along the testicular vein of the corresponding side with the development of varicose veins of the spermatic cord.

The incidence of varicocele in renal tumors varies. It is usually a late symptom in the clinical course of the disease.

Other signs indicating impaired venous outflow include symptoms resulting from acute and chronic thrombosis of the inferior vena cava. Tumor thrombus develops as a result of tumor growth into the renal vein and inferior vena cava, from where it can sometimes reach the heart.

Histological examination of thrombi extracted from the renal veins or inferior vena cava indicates that, along with tumor cells, the thrombus contains blood clots.

Acute thrombosis of the inferior vena cava is a rare phenomenon, characterized by a violent onset with a sharp deterioration in the general condition of the patient. In this case, a sudden severe circulatory disorder in the lower extremities, abdominal organs and pelvis is noted. If the thrombosis is widespread, severe dysfunction of the kidneys and adrenal glands occurs. Blockage of the veins of both kidneys leads to anuria and rapid death. If the thrombosis develops gradually, venous outflow begins to recover through collaterals and the patient suffers less.

In case of partial thrombosis of the inferior vena cava, symptoms increase slowly, gradually. Edema of the lower extremities is an important sign that the inferior vena cava is bloated by a tumor mass and the operability of kidney cancer is questionable.

The most characteristic symptom of chronic thrombosis of the inferior vena cava is swelling of the lower extremities, rising as the process spreads upward, in front capturing the abdominal wall to the level of the navel, in the back - to the lumbar region, sometimes to the base of the chest. Often the swelling spreads to the genitals.

Sometimes kidney cancer manifests itself with a clinical picture of acute abdomen, which occurs due to acute bleeding during rupture of sharply dilated veins of the perirenal tissue or massive hemorrhage into the tumor tissue. If the integrity of the fibrous capsule is damaged, then blood flows into the perirenal tissue, forming an extensive perirenal hematoma.

The general condition of patients often remains satisfactory for a long time and often does not correspond to the severity of the underlying disease. Symptoms such as general weakness, loss of appetite, cachexia are usually signs of a widespread process.

Diagnosis of kidney cancer

Diagnosis of tumors of the upper urinary tract is quite difficult, which is due, on the one hand, to the rarity of the disease and insufficient oncological alertness of doctors, and on the other hand, to the fact that the clinical and laboratory manifestations of kidney cancer are similar to those of other urological and oncourological diseases.

Improvements in diagnostic methods have now led to the fact that the detected kidney cancer is small in size and limited within the organ, so it is not detected using physical examination methods.

Ultrasound examination (US) currently plays a leading role in recognizing the tumor process in the kidney. The method is highly informative, does not require preliminary preparation, and is safe.

In the presence of a tumor, the kidney contours are deformed, and multiple echo signals appear inside the tumor. Using a Doppler sensor allows us to determine hypervascularization, which is more typical for kidney cancer. Ultrasound examination is of great importance in the differential diagnosis of the tumor process from other pathological changes in the kidney. Using ultrasound scanning, we determine the state of regional metastasis zones.

X-ray computed tomography (XCT) is the main diagnostic method for kidney cancer. Kidney cancer is defined as a node that deforms the cortex of the kidney and its cavity or spreads beyond the organ. The accuracy of the method is 95%. With the help of XCT, it is possible to determine the spread of the tumor process to the surrounding vessels.

Magnetic resonance imaging (MRI) is of great importance in the diagnostics of renal masses. It is indicated for patients with severe renal dysfunction, allergic reactions to iodine-containing contrast solutions, and contraindications to ionizing radiation. The advantage of MRI is the ability to diagnose a tumor thrombus and determine its upper limit.

Contraindications to MRI include claustrophobia, the presence of metal prostheses, surgical metal staples. An additional limitation is the high cost of the method.

Multispiral computed tomography (MSCT) makes it possible to assess not only the prevalence of the tumor process, but also the renal pelvis and vessels.

Angiography is currently performed only in cases where precise information is required on the number of renal arteries, the vascular architecture of the kidney, and also when there is a suspicion of involvement of the main vessels.

Excretory urography allows to clarify the functional and morphological features of the kidney affected by the tumor, as well as the condition of the opposite kidney. This method allows to suspect a volumetric process in the kidney, without allowing to solve the issue of staging, therefore it is rarely used at present.

The algorithm for examining patients has changed: after a neoplasm is detected by ultrasound, MSCT is performed, which eliminates the need for excretory urography and complex vascular examination. Both MSCT and MRI allow one to judge the presence and extent of a tumor venous thrombus, and MRI with signal suppression from the paranephrium - about the invasion of the fibrous capsule of the kidney, which facilitates differential diagnostics of T1a, b and T3a stages of the disease.

Despite the enormous potential of tomography, in some cases (suspected benign tumor structure, unclear organ affiliation, severe intercurrent background, etc.) it is necessary to establish the morphological structure of the neoplasm before surgery. This can only be done by biopsy, the information content of which reaches 90%. Telomerase activity is determined to increase the information content of biopsy. The telomerase enzyme is a ribonucleoprotein complex that synthesizes the terminal sequences of DNA telomeres. Telomeres protect the ends of chromosomes from enzymatic destruction, prevent chromosomes from fusing with each other, and are necessary for doubling the genetic material during cell division. High enzyme activity is observed in human germ, stem, and sex cells, as well as in macrophages and leukocytes. Telomerase activity is absent in most somatic cells, although information about this enzyme is encoded in the DNA of all cells. During the process of malignant cell transformation, telomerase is activated, which provides the malignant cell with the ability to divide unlimitedly. Most malignant tumors are characterized by high telomerase activity. Kidney cancer is no exception.

Laparoscopy can be used for kidney cancer biopsy. There are many studies confirming the high diagnostic value of kidney biopsy for tumors. Visualization of the organ is possible not only by ultrasound scanning, but also by laparoscopic and retroperitoneoscopic access. Transperitoneal laparoscopic visualization of the neoplasm is performed and the tumor contents are aspirated for cytological examination.

The most important laboratory parameters that should be determined in patients with kidney cancer are: hemoglobin and ESR, which serve as prognostic factors, creatinine, which allows one to assess the functional state of the kidneys, alkaline phosphatase, an increase in which may indicate the presence of metastases to the liver and bones, and serum calcium to exclude hypercalcemia.

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