SPACE OCCUPYING RENAL MASSES
These masses may be classified within several different forms:
Benign – Malign
Cystic (full with water) – Solid
- Benign Tumors
Lipoma and others
- Malign Tumors
- ADENOCANCER OF THE KIDNEY
[renal cell ca, Hypernephroma, Grawitz tumor]
- Wilms tumor (nephroblastoma)
- Metastatic renal tumors
Cysts are saccules filled with water. They may be monitored within different regions of the body and kidney is one of them. As cysts may not cause any symptoms; they also may cause some problems such as;
- High blood pressure
- Kidney failure
HOW IS IT UNDERSTOOD ?
Renal cysts may be diffuse with renal cancer. Diagnosis for kidney cyst is put with radiological methods such as ultrasonography, tomography. Genetic studies are also useful to diagnose some familial cysts.
Kidney cysts are classified according to age of detection, location and other symptoms. Some cysts are harmless and most common cyst types. They do not cause any symptom in general and do not require any treatment. Frequency of simple cysts increase by aging. Familial cysts shall include the abovementioned problems in general, therefore careful follow-up is useful.
TREATMENT FOR RENAL CYSTS
Generally, it does not create any problem until diameter of 10 cm. So, treatment of such cysts is not necessary as well as they grow much. Following the cyst structure and size is enough by annual ultrasonographic controls. When the cysts grow over 10 cm and/or they have causes high blood pressure, inflammation and kidney failure, treatment is done. Close relatives should be screened for the cyst in familial cysts. Close kin marriages must be prevented in some cysts which present familial characteristics.
The purpose of the treatment is to annihilate the pressure effect created by the cyst.
a- Percutaneous ultrasonic aspiration: A needle is inserted into the cyst with guidance of ultrasonography and cyst fluid is discharged. It is temporary but also easy method. It does not require anesthesia and may be performed within polyclinic environment.
b- Surgical: The cyst is removed by open surgery or laparoscopic techniques. It provides definite therapy. However, it requires hospitalization and is performed under anesthesia in OR environment.
BENIGN PARENCHYMAL TUMORS
It is the most common solid and benign tumor of the kidney and originated from the tubule epithelium (%7-22). Becoming malignant potential increases in proportion with the size of the adenoma (over 3 cm). Therefore, it may require partial or radical nephrectomy.
It consists of 5% of renal tumors. Angiomyolipoma is a yellow-gray colored, oval or circular benign tumor without capsule which grows rapidly and invades locally. There is renal hamartoma in 50% of the patients with tuberosclerosis and it is bilateral. It is more common in middle aged women. Pure angiomyolipoma is generally solitary and unilateral. Angiomyolipoma is rich in fat, smooth muscle and vessel and when it is over 6 cm, it may cause lumbar pain, hematuria, hypertension and hemorrhagic shock as a result of intrerenal and perirenal hemorrhage.
Diagnosis: It is diagnosed easily by ultrasonography (US), computed tomography (CT) or Magnetic Resonance Imaging (MRI) (because of the fatty tissue in it). Monitoring the angiomylolipoma is important. It does not require any treatment until it reaches up to 6 cm. Annual US monitoring is enough. For problem creating conditions; urgent nephrectomy, partial or nephron protecting nephrectomy or embolization are done.
It consists of 3 to 5% of solid tumors of the kidney and 6% of them are bilateral. It is more common in men than women and seen after 40s. It is asymptomatic in general (does not cause any complaint). When the tumor reaches to certain sizes, microohematuria or macrohematuria, lumbar pain and mass may be seen.
Histologically, low grade (grade I) oncocytomas are eosinophilic, big uniform cells with a granular cytoplasm and they are benign.
Diagnosis: It is diagnosed by US and CT. Differential diagnosis from the renal cancer is difficult, therefore partial nephrectomy is done for low grade, small volume tumors (smaller than 3 cm) and radical nephrectomy is performed for high grade or big volume tumors.
MALIGN TUMORS (Tm)
It is also called Renal adenocarcinoma; Renal Cell Ca, Hypernephroma or Grawitz tumor. It consists of 3% of all malign tumors and 85% of malign tumors of the kidney.
It is detected between 40 to 70 years of life and most common on 60s. It is 2 or 3 times more frequent in men than women.
Although the cause is not definite, it has been reported that genetic factors, living in developed countries (due to easier use of diagnosis methods), eating foods rich in fats and cholesterol, working in cadmium, asbestos, petrochemistry and leather industry and smoking may increase to kidney cancer. In pathology, it is a circular-oval, off-yellow tumor with a pseudocapsule including hemorrhagic, necrotic, cystic and calcification areas in patches and soft and hard sites in patches.
Kidney cancer caused by proximal tubular epithel, is transparent histopathologically,composed of granular or sarchomatoid cell and tubular structured in the same tumor more than one cell type are composed of tubular, papills ,cycthic and solid structure.
Differentiation is not so important in renal adenocarcinoma.
When renal adenocarcinoma is diagnosed, 40 to 56% of the cases have developed metastasis.
Direct spread :
The tumor is intrarenal at first and grows expansively and damaged the kidney contour by pushing the kidney tissue around the tumor. Similarly, it causes pelvicaliceal deformation by pushing the calyxes and the pelvis. It passes through the fibrous capsule of the kidney by time and reaches to the fatty tissue, Greato’s fascia, surrounding tissues and organs; the kidney becomes a fixed organ.
Hematogeneous spread :
The tumor is infiltrated into intrarenal veins within the early periods mostly. The tumor thrombus is seen in intrarenal veins by time and then the tumor thrombus may move to the renal vein and vena cava. Sometimes, it may obliterate the vena cava completely. Distant metastasis is into the lung by the venous path, then liver, bone, brain and other kidney.
Lymphogenous spread :
Kidney pedicle (the area where the vessels enter) metastasize into the surrounding lymph glands and then other lymph glands and other organs mainly lung.
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor is < 7 cm, limited to the kidney
T2 Tumor > 7 cm, limited to the kidney
T3 Tumor goes beyond the renal capsule
T3a Tumor extends into the suprarenal or perypheral tissues but not beyond the Gerota fascia
T3b Tumor extends into the vena cava below the diaphragm
T4 Tumor invades beyond the Gerota fascia
N0 No regional lymph node metastasis
N1 Metastasis in single egional lymph node
N2 Metastasis in multiple lymph nodes
M0 No distant metastasis
M1 Distant metastasis
It has 3 major findings which appear at late period.
- Hematuria (bloody urination)
- Lumbar pain
Besides; varicocele, hypertension, fatigue, weight loss, anemia, fever and symptoms of metastasis may be detected at further stages. The kidney can be palpated as an enlarged mass only in slim persons and advanced cases.
Macroscopic or microscopic hematuria in urine tests, anemia, levetaion of sedimentation, also hypercalcemia (elevetaion of blood calcium level), hypertension, polycythemia (much red blood cells within the blood)
Ultrasonography: Diagnosis value for solid or cystic kidney tumors is 90%. It is the first diagnosis methods that should be applied.
Urography (DUSG-IVP) : Enlargement, irregularity or cembering on kidney contours, graying on psoas shadow, pelicalicial deformation, the ureter pushed to the medial side in lower pole tumors, function loss as a result of parenchyma damage are monitored.
Computed Tomography (CT) : By measuring the tissue density, the tumor is determined as benign or malign with an accuracy of 90%. At the same time, diagnosis for local dissemination, regional lymphadenopathy and tumor thrombus on the renal vein or vena cava, liver, spleen metastasis may be possible with CT.
Color Doppler US and Veno-Cavagraphy : It should be done for suspicious tumor thrombus detected on CT.
Renal Angiography : When a substance that will contract the vessels and vessels are stained for the cases where CT is insufficient for differential diagnosis of solid tumors, differential diagnosis is performed by not contracting new vessels appeared on tumor region.
Pulmonary cyntigraphy or Pulmonary tomography for distant metastasis and bone cyntigraphy for staging should be performed.
For the treatment of malign kidney tumors, 1st Surgical, 2nd embolization and 3rd Immunotherapy options are present.
Surgical treatment may be performed with open surgery and laparoscopic surgery techniques technically and following surgical methods may be applied according to the tumor type, location, size, being unilateral or bilateral, general condition of the patient and experience of the surgeon consequently;
- radical nephrectomy
- Nephron protecting surgery
Partial nephrectomy or tumor enucleation (tumor removal only).
Kidney cancer is radio-resistant (resistant to the radiation). However, it may be applied for palliative purpose.
There is not any single or combined cytostatic agent which is significantly effective to the kidney cancer. Although many combined therapies are tried, efficiency is about 5 to 10% and short.
Single interferon or combination of interferon with vinblastine and interleukin are used recently, but results are not blissful.
PROGNOSIS (EXPECTATION OF LIFE)
While the 5 years survival is 90 to 100% for early stages, this ratio decreases to about 20% for advanced stages.
Routine check-ups (complete abdominal ultrasonography) are quite important. The sooner the disease is diagnosed, treatment is such easier and more successful !!!
NEPHROBLASTOMA (WILMS’ TUMOR)
Nephroblastoma is an embryological tumor and most common between 1 and 3 years and rarely in adults. It consists of 5% of childhood tumors and 26% of pediatric solid organ tumors. 5% of them are bilateral.
The tumor is big and solitary in general. It has a soft consistency and there are hemorrhagic, necrosis and cystis areas in patches, it has a pseudocapsule.
Like kidney cancers, it metastasize directly, through lymph glands and veins. The tumor grows rapidly within a short period and disseminates into the adjacent tissues and organs. Distant metastasis appears into regional lymph glands by lymphatic path, into the lung, liver, suprarenal, bone and brain via venous path.
STAGING (National Wilms’ Tumor Study Group NWTS)
- Tumor is within the kidney, capsule is intact. The tumor has been removed completely by the surgery.
- The tumor has passed the kidney border. It is invaded into the perirenal fatty tissue. The tumor has been removed completely.
- The tumor has metastasized into the adjacent tissues and organs, peritoneum and regional lymph glands. Liver is intact. The tumor could not be removed completely.
- There are distant metastasis.
- Bilateral kidney tumor.
Mass is the most important finding. There is an asymmetry on the abdomen due to the mass.
Pain: Abdominal pain is present with a ratio of 20 to 30% of the cases.
Hematuria: It is seen in 10% of the cases.
Fever- nausea, vomiting, constipation- Hypertension- Varicocele are other possible symptoms.
Treatment is RADICAL NEPHRECTOMY and then CHEMOTHERAPY and/or RADIOTHERAPY according to the cell type in the pathology.
Drugs such as actinomycin D, vincristin, doxorubicin, adriamycine are used in chemotherapy for 6 to 15 months.
Survival after the surgery when the tumor is detected within the early stage is about 100%.