Cells also can directly invade the abdominal lymph nodes that drain the kidney and extend into structures surrounding the kidney (perinephric) such as fat, adrenal gland and liver. This kind of invasion is found at diagnosis in about 45 percent of cases. Invasion of the inferior vena cava is found in 10 to 15 percent of cases and of local lymph nodes in 10 to 30 percent. In over half the cases with lymph node involvement, distant metastases are found.
In over 40 percent of patients, the symptoms that cause them to seek medical attention are due to metastases.
What Causes It Risk factors are poorly defined, although the incidence is twice as high for those using tobacco (cigars, chewing tobacco, cigarettes).
