Renal cell carcinoma: what do we know about kidney cancer
Adenocarcinoma of a kidney is a renal cell carcinoma that originates from the epithelium of the tubule of the kidney. Manifestations of adenocarcinoma of the kidney are pain in the lower back, hematuria, an increase in the size of the kidney, anemia, cachexia.
Possible metastasis of the tumor into the lungs, paracaval and para-aortic lymph nodes, bones, liver, adrenals, opposite kidney. Adenocarcinoma is diagnosed during renal ultrasound, cystoscopy, excretory urography, ureteropyelography, renal CT.
Morphological verification of the diagnosis is performed by puncture biopsy of the kidney and histological examination of the biopsy specimen. The detection of renal adenocarcinoma is an indication for nephrectomy followed by radiation therapy.
Adenocarcinoma of the kidney is about 2.5% of the number of neoplasias of various localizations. In urology, adenocarcinoma is the most common histotype of kidney cancer in adults. Among all tumors of the kidney, adenocarcinoma accounts for 90% of cases. Kidney adenocarcinoma usually develops at the age of 40-70 years; with the same frequency affects the left and right kidney; 2 times more often diagnosed in men.
Macroscopically, the adenocarcinoma of the kidney looks like a node of a soft-elastic consistency. In the section, intermittent areas of hemorrhage and necrosis are seen, giving the tumor a mottled appearance. Tumor growth can be multidirectional – towards the renal capsule or the bowl-pelvis complex; rather quickly adenocarcinoma sprouts the renal veins, the lower hollow vein, adjacent tissues; Metastasizes to lymph nodes, lungs, bones, liver, brain.
The microscopic structure of the kidney adenocarcinoma is represented by strands and clusters of polygonal cells having a light protoplasm containing glycogen and lipids; The stroma of the tumor is weakly expressed.
Causes of a kidney cancer
The kidney adnocarcinoma has a polyethological and completely unclear nature. A certain role in tumor development is played by kidney diseases (glomerulonephritis, pyelonephritis), trauma; the effect on the renal tissue of chemical agents (nitrosoamines, hydrocarbons, aromatic amines), radiation exposure, intoxication (smoking).
Adnocarcinoma often develops from a benign adenoma of the kidney, therefore, all revealed kidney neoplasms are subject to removal and histological examination. Correlation of kidney adenocarcinoma with obesity and hypertension was noted. Less common causes of adenocarcinoma are dysontogenetic disorders, hereditary forms of kidney cancer.
Stages of renal adenocarcinoma
Kidney adenocarcinoma is a type of renal cell carcinoma (hypernaroid cancer) and can have a different degree of differentiation.
The international classification of the TNM system identifies the following stages of renal adenocarcinoma:
- T1 – tumor spread is limited to the renal capsule
- T2 – tumor germination of the fibrous capsule of the kidney
- T3 – the vascular pedicle of the kidney or the paranephric fatty tissue is involved in the tumor process
- T4 – the tumor sprouts into the nearest organs;
- Nx – preoperative assessment of regional lymph nodes is not possible
- N1 – regional metastasis is determined using radiological or radioisotope techniques
- M0 – absence of distant metastases
- M1 – single metastasis in distant organs is defined
- M2 – multiple distant metastasis is defined.
In adenocarcinoma of the kidney, distant metastases are detected in 50% of patients, and renal vein tumor growth in 15%. More often distant metastases are located in the lungs (54%), regional paracaval and para-aortic lymph nodes (46%), bone skeleton (32%), liver (36%), opposite kidney (20%), adrenal (16%). Kidney adenocarcinoma metastases can manifest clinically even before the primary focus is detected or occur after a time after nephrectomy for kidney cancer.
In the clinical course, adenocarcinomas of the kidney distinguish a latent (latent) period, as well as periods of local and general manifestations.
Symptoms of renal cell carcinoma
In the latent period, clinical manifestations are absent. The development of local symptoms is accompanied by the appearance of macromuturia and pain, an increase in the kidney. Hematuria is noted in 70-80% of patients with kidney adenocarcinoma. The discharge of blood in the urine occurs unexpectedly, more often in the form of filamentous clots 6-7 cm in length.
Hematuria usually has an episodic character, stopping and resuming again. In the case of intensive renal bleeding (profuse hematuria), thrombosis of the renal veins, blockade (tamponade) of the bladder and acute urinary retention may occur.
Pain syndrome in kidney adenocarcinoma occurs in 60-70% of observations. The pain is dull, aching, localized in the lower back, irradiates in the groin and thigh; at hematuria heights can be amplified to renal colic. The increase in the kidney is noted in 75% of cases. In later stages, a tumor that is palpable through the abdominal wall is determined.
With the germination of adenocarcinoma of the kidney of venous vessels, varicose veins of the labia are observed in women, varicocele in men.
In the period of common manifestations, weight loss, weakness, hypertension progresses; there is a causeless persistent increase in body temperature, anemia, cachexia. In far-reaching stages, paraneoplastic amyloidosis and nephrotic syndrome develop (generalized edema, massive proteinuria, hypoproteinemia, hypoalbuminemia, etc.).
Diagnosis of renal cell carcinoma
In the diagnosis of kidney adenocarcinoma, laboratory and instrumental techniques are used. In the general analysis of urine, pronounced hematuria, moderate proteinuria;
in the blood – normochromic anemia, an increase in ESR.
The leading role in identifying adenocarcinoma of the kidney is given to ultrasound, endoscopic and X-ray diagnostics. An informative method for confirming adenocarcinoma is ultrasound of the kidneys, which, in addition to visualizing the tumor, makes it possible to accurately perform a puncture biopsy of the kidney with the collection of tumor tissue for the morphological study of the biopsy.
To perform cystoscopy resorted at the time of hematuria, which allows you to determine the ureter from which blood is excreted.
Carrying out of excretory urography allows to consider uneven contours and enlarged sizes of a kidney, to reveal deformation, amputation of calyces, deviation of ureters, defects of filling of pelvis. In some cases, retrograde ureteropyelography, renal angiography, nephroscintigraphy are performed.
The fact of distant metastasis of renal adenocarcinoma is established with the route of lung radiography, scintigraphy of the skeleton, ultrasound of the liver, adrenal and retroperitoneal space. Adenocarcinoma of the kidney is differentiated from nephrolithiasis, adenoma of the kidney, chronic glomerulonephritis, pionephrosis, kidney tuberculosis, polycystosis.
Treatment of renal cell carcinoma
With adenocarcinoma of the kidney, it is optimal to carry out combined treatment, including radical surgery on the kidney and radiation therapy. In the early stages of kidney adenocarcinoma, a partial nephrectomy can be performed. With the widespread process, total nephrectomy is performed, removal of paranephric and retroperitoneal tissue with regional lymph nodes.
The growth of the tumor of the inferior vena cava and even the presence of single distant metastases do not prevent the performance of a nephrectomy. With a single metastasis in the lungs, the second stage removes the metastatic focus. The combination of surgical treatment with radiation increases the survival rate for kidney adenocarcinoma.
Total cancerous damage of both kidneys can require a binarectomy with transfer of the patient to hemodialysis. The widespread form of renal adenocarcinoma, characterized by extensive metastasis and tumor germination, involves symptomatic and palliative treatment with radiation and chemotherapy.
Prognosis and prevention of kidney adenocarcinoma
After nephrectomy patients are subject to urologist monitoring, dynamic lung radiography for the purpose of early detection of metastases. The long-term prognosis for adenocarcinoma of the kidney is unfavorable: there is a high percentage of late metastasis of the tumor in the bones and lungs. After total nephrectomy, a 5-year survival margin is overcome by 40-70% of patients.
To avoid the possibility of developing adenocarcinoma of the kidney, it is recommended to observe a healthy lifestyle, exclude bad habits, timely treatment of kidney diseases. It is necessary to carry out prophylactic ultrasound of the kidneys and immediately address a nephrologist (urologist) in case of pain in the lower back or blood in the urine.