Hypernephroma is a malignant epithelial tumor of the kidney, a type of renal cell carcinoma. It is manifested by local and paraplastic (general) symptoms: macrohematuria, pain in the kidney area, palpable tumor-like formation, deterioration of the general condition, weakness, weight loss, etc. Excretory urography, retrograde pyelography, renal angiography, kidney ultrasound, CT and MRI, fine needle kidney biopsy are used to recognize hypernephroma and differential diagnosis. Treatment is carried out in compliance with oncological principles, including nephrectomy with lymphadenectomy, radiation and drug chemotherapy.
Meaning
Hypernephroma (clear cell adenocarcinoma, Gravitz tumor, hypernephroid cancer) accounts for 2-5% of malignant neoplasms in general, and in clinical urology – up to 85% of all cases of kidney cancer. Hypernephroma refers to tumors of epithelial origin and can develop from almost any structure of the nephron: glomerular capsule, Henle loop, distal and proximal tubules. In men, hypernephroma is detected 2.5-3 times more often than among women. In 2/3 of cases it occurs in patients aged 40-70 years. The TNM stages of hypernephroma development are similar to those in renal cell carcinoma.
Causes
The causes of neoplasia remain unknown, but nephrologists identify certain factors, the influence of which significantly increases the likelihood of kidney cancer. It is known that hypernephroma is 2 times more often detected in males and smokers. Smoking is considered the main risk factor for the occurrence of tumors of urological localization – bladder and kidney cancer. Meanwhile, quitting smoking leads to a 15% reduction in this risk over 25 years. Various chemicals have an adverse effect on the renal epithelium: gasoline, asbestos, cadmium, organic solvents, herbicides, phenacetin-containing drugs, etc.
It is noted that the frequency of hypernephroma detection correlates with diseases such as obesity, hypertension, diabetes mellitus, as well as pathology of the kidneys themselves (chronic pyelonephritis, nephrolithiasis, tuberculosis, dystopia, polycystic, nephrosclerosis, etc.). Patients with renal insufficiency who are forced to undergo prolonged hemodialysis are more predisposed to the development of neoplasms. There is an increased risk of hypernephroma in patients with genetic pathology (Hippel-Lindau disease), burdened with a family history (hereditary papillary cell carcinoma, hypernephroid cancer).
Pathogenesis
Hypernephroma is a soft mottled node with a pseudocapsule, microscopic examination of which reveals light polygonal and polymorphic cells containing lipids, numerous mitoses. Tumor cells unite into alveoli and lobules, merging into tubular and papillary structures. Stroma is poorly expressed, hemorrhages and tumor necrosis are typical. In 45% of cases, invasive growth of hypernephroma, germination of the pelvis by it, and spread in the form of tumor thrombi through the veins are detected. Neoplasia metastasis is lymphogenic (to the lymph nodes) and hematogenic (to the lungs, contralateral kidney, liver, bones).
Symptoms
It may take several years from the moment of the appearance of a tumor in the kidney to the development of the first clinical symptoms. The clinic of hypernephroma is characterized by a classical renal triad (hematuria, pain, palpation-defined tumor) and extrarenal manifestations. The first thing that is usually noted by 2/3 of patients is the appearance of blood impurities in the urine (hematuria). As a rule, hematuria develops suddenly and is not accompanied by pain; it can be transient, be insignificant, total or profuse.
Frequent or intense hematuria leads to severe anemia of the patient. In some cases, microhematuria occurs, which can only be detected by examining urine. The formation of blood clots can cause occlusion of the ureter and an acute attack of renal colic. Very characteristic of hypernephroma is the appearance of pain after hematuria, and not before it, as with kidney stones. More often, the pain is constant and has a dull aching character.
Palpation of the altered kidney through the anterior abdominal wall or lower back is possible only in half of cases. Compression of veins (renal, inferior vena cava, testicular) in men can lead to the development of varicocele. Paraplastic (general) manifestations of hypernephroma include causeless fever with chills, myalgia, arthralgia, weakness, decreased appetite, weight loss, nausea and vomiting.
Diagnostics
Detection and differential diagnosis of hypernephroma requires a detailed urological examination, including excretory urography, retrograde pyelography, renal angiography, kidney ultrasound, kidney CT and MRI, fine-needle kidney biopsy and morphological analysis of the tumor. Already during the examination of the patient, a characteristic asymmetry of the abdomen, an increase in the venous pattern on the anterior abdominal wall in the form of a “jellyfish head”, dilation of the veins of the spermatic cord, swelling on the lower extremities can be revealed.
In a blood test, an increase in ESR, anemia, polycetemia is reversed; in urine analysis, erythrocyturia. To exclude the source of bleeding in the bladder (stones, diverticula, tumors), cystoscopy may be required. At the first stage, ultrasound of the renal vessels allow to obtain information about the location and size of the volume formation, the probability of vascular invasion.
Intravenous urography detects a deformation or defect in the filling of the cup-pelvic system, the displacement of the ureter to the spinal column. With a marked decrease in kidney function and the inability to obtain excretory urograms, retrograde pyelography is resorted to. To study the interest of renal vessels in tumor invasion, renal angiography and phlebography are performed. With the help of CT or MRI, the size and extent of hypernephroma are detailed, enlarged lymph nodes are detected.
For the purpose of preoperative morphological verification of the diagnosis and staging of the oncoprocess, a kidney biopsy or a lymph node biopsy is performed to determine the histotype of the tumor formation. To exclude the possibility of hypernephroma metastases in distant organs, osteoscintigraphy, chest X-ray, liver ultrasound are performed.
Treatment
If a tumor is detected, surgical treatment, X-ray irradiation or systemic chemotherapy can be undertaken. With satisfactory function of the second kidney and operability of hypernephroma, radical nephrectomy is performed, including removal of the kidney with the adrenal gland, surrounding tissue and lymph nodes. At stage I of the tumor process (neoplasia with a diameter of less than 7 cm, not extending beyond the capsule), poor functioning or absence of another kidney, partial nephrectomy can be performed.
If radical intervention is not possible, arterial embolization can be undertaken, aimed at blocking the blood vessels of the kidney that feed the tumor. X-ray or chemotherapy for hypernephroma can be used in isolation or in combination with the surgical stage. Such methods as cryotherapy, radiofrequency ablation, HIFU therapy with high-energy focused ultrasound have experimental significance.
Prognosis and prevention
In general, long-term results in hypernephroma are the same as in renal cell carcinoma. For prevention, harmful carcinogenic effects (smoking, chemical and medicinal agents) should be excluded, and the existing kidney pathology should be eliminated in a timely manner. The key to early detection of neoplasms can be regular ultrasound of the kidneys to practically healthy people. If there is blood in the urine, lower back pain, a detailed examination is necessary.
