Renal granular cell carcinoma is a histological form of renal cell carcinoma developing from the parenchyma of the organ. It is manifested by renal (hematuria, pain, palpable tumor) and extrarenal (fever, weakness, weight loss, etc.) symptoms. The diagnosis is established on the basis of ultrasound of the kidneys, excretory urography, angiography, MRI, CT, radioisotope scintigraphy. Treatment includes partial or radical nephrectomy, often – adrenalectomy, immunotherapy; less often – hormone therapy, chemotherapy or radiation therapy.
Meaning
Renal granular cell carcinoma (granular cell carcinoma) in clinical urology occurs in 7-12% of all cases of renal cell carcinoma. Macroscopically, neoplasia has a brownish color due to the accumulation of phospholipid complexes in numerous mitochondria filling cancer cells. Microscopic examination of the tumor is represented by polygonal cells with a wide granular cytoplasm, varying degrees of cellular atypia and polymorphism, extensive areas of hemorrhage and necrosis. A distinctive feature of the neoplasm is a tendency to invasion of the renal vein.
Causes
It is not possible to judge the causes of the renal granular cell carcinoma. Currently, prognostic potential risk factors that increase the likelihood of developing malignant tumors in general have been identified. It is noted that the peak incidence is observed at the age of 50-70 years, and kidney cancer is 2-3 times more common in men. The risk of developing pathology is higher in representatives of the black race.
The main predisposing factor is considered to be smoking, which increases the likelihood of kidney cancer by 2 times. Other probable causes include genetic predisposition, some hereditary diseases, immunodeficiency, obesity, exposure to ionizing radiation, the patient being on long-term hemodialysis, etc.
Classification
The prevalence of granular cell kidney cancer is estimated by the TMN system:
- T1 – carcinoma is located in the center of the renal parenchyma, is not palpable and is detected exclusively radiologically.
- T2 – palpable carcinoma is determined without signs of locally invasive growth.
- T3 N1– carcinoma grows into the adrenal gland, veins, or surrounding tissues, or there is a single metastasis to the regional lymph node.
- T4 N1(N2) M0 (M1) – multiple metastases to lymph nodes, germination to neighboring organs, the presence of distant metastasis.
Metastasis of kidney cancer occurs along the circulatory and lymphatic pathways. Regional and distant metastases are detected in more than half of cases. The zones of regional metastasis are paraaortic and paracaval lymph nodes; distant metastases more often affect the lungs, pelvic bones, spine, shoulder girdle, cranial vault, ribs. Local invasion is observed in the paranephral tissue, postoperative scar, muscles and subcutaneous adipose tissue of the anterior abdominal wall.
Symptoms
The clinical picture consists of renal and extrarenal manifestations. The renal symptoms include the classic triad – the presence of a palpable tumor, hematuria and pain. Usually there are 1 or 2 symptoms of the triad, but all of them, as a rule, already indicate a widespread tumor process. Hematuria with renal granular cell carcinoma is observed in 50-60% of cases, is characterized by high intensity, develops suddenly and is often not accompanied by pain syndrome.
An acute pain attack may occur after the cessation of hematuria, when the ureter is obstructed by a blood clot. With non-tumor kidney lesions occurring with hematuria (hydronephrosis, urolithiasis), pain usually precedes the appearance of blood in the urine. In the case of kidney cancer, hematuria is intermittent, while the intervals between bleeding are gradually shortened. Pain in the lumbar region occurs in almost half of patients; palpable tumor – in 30-40%. Extrarenal (extrarenal) symptoms usually include causeless fever, deterioration of well-being, loss of appetite, weakness, anemia, weight loss.
Complications
In 5-10% of patients with a blastomatous process in the kidneys, arterial hypertension develops. In men, an important symptom of carcinoma is the development of varicocele, which may be due to compression or tumor invasion of the renal vein, one of the testicular veins or thrombosis of the inferior vena cava.
Metastases of kidney carcinoma to the lungs may be an accidental find during fluorography or find themselves hemoptysis. Metastatic skeletal lesion proceeds with intense persistent pain, not relieved by narcotic drugs. With the involvement of tubular bones (femoral, humerus), pathological fractures may develop; if the spine is interested, paraplegia, pelvic organ dysfunction.
Diagnostics
Visually and palpationally, only advanced forms of kidney cancer can be detected. During examination, a nephrologist may pay attention to varicocele, swelling of the lower extremities, dilation of subcutaneous veins on the anterior abdominal wall. Palpation of the tumor and the degree of its mobility allow us to judge the prevalence of the cancer process.
From laboratory diagnostic tests, general urine analysis (erythrocyturia, leukocyturia, proteinuria) and general blood analysis (anemia, increased ESR), biochemical blood tests are used during the examination, but all the changes detected in them are non-specific. Pathognomonic signs of renal carcinoma are changes in the metabolism of serum proteins (transferrin, ferritin, albumin) detected by immunodiffusion analysis.
An important stage of oncourological examination is ultrasound of the kidneys, through which it is possible to detect deformation of the contours of the parenchyma, tumor germination into the vessels, vein thrombosis, enlarged regional lymph nodes, etc. Ultrasonography helps to differentiate carcinoma from hydronephrosis, pionephrosis, polycystic kidney, solitary kidney cyst.
The X-ray examination begins with performing an overview urography, which allows you to judge the change in the configuration of the kidney. In the future, excretory urography is performed, which gives information about the morphological and functional state of the affected and healthy kidney. To assess the interest of the renal vessels and the degree of tumor vascularization, they resort to performing ultrasound and renal angiography; in case of suspicion of a tumor thrombus, lower cavography and renal venography.
In order to stage the blastomatous process, magnetic resonance imaging, computed tomography, nephroscintigraphy are used. Kidney biopsy is rarely used due to the danger of tumor dispersion. In order to detect distant metastasis, radiography of the lungs and bones, ultrasound of the abdominal cavity is shown.
Treatment
When detecting operable granular cell carcinoma, surgical tactics are indicated. Kidney surgery is performed even if a single metastasis is detected, since it allows prolonging the patient’s life. With early diagnosis of carcinoma, partial nephrectomy is possible, but total nephrectomy is more often performed, often with unilateral adrenalectomy and removal of regional lymph nodes, extraction of tumor thrombi from the renal and inferior vena cava.
The appointment of radiation therapy, chemotherapy or hormone therapy is resorted to when renal cancer is inoperable. The best prognostic result is achieved by conducting immunotherapy with alpha-interferon, 5-fluorouracil, interleukin-2, which allows to increase the survival time.
Prognosis and prevention
The long-term prognosis is largely determined by the stage of blastomatous lesion. The course of renal granular cell carcinoma is unfavorable in most cases; the prognosis worsens with the growth of the tumor into the renal vein, the presence of distant metastasis. Prevention of kidney cancer requires quitting smoking, excluding adverse chemical and ionizing effects on the body.