Introduction Many cancers are associated with inferior vena cava (IVC) obstruction, but very few cancers have the ability to propagate within the lumen of the renal vein or the IVC. Renal cell carcinoma is the most common of these cancers. Renal cancer with IVC extension has a high rate of recurrence and a low five year survival rate. Case presentation A 62-year-old Caucasian woman previously in good health developed the sudden onset of severe reflux symptoms and right-sided abdominal pain that radiated around the right flank. A subsequent ultrasound and CT scan revealed a right upper pole renal mass with invasion of the right adrenal gland, liver, left renal vein and IVC. This appeared to be consistent with stage III renal cancer with IVC extension. Metastatic nodules were believed to be present in the right pericardial region; the superficial anterior abdominal wall; the left perirenal, abdominal and pelvic regions; and the left adrenal gland. The pattern of these metastases, as well as the invasion of the liver by the tumor, was thought to be atypical of renal cancer. A needle biopsy of a superficial abdominal wall mass revealed a surprising finding: The malignant cells were diagnostic of large-cell, B-cell non-Hodgkin's lymphoma. The lymphoma responded dramatically to systemic chemotherapy, which avoided the need for nephrectomy. Conclusion Lymphomas only rarely progress via intraluminal vascular extension. We have been able to identify only one other case report of renal lymphoma with renal vein and IVC extension. While renal cancer would have been treated with radical nephrectomy and tumor embolectomy, large-cell B-cell lymphomas are treated primarily with chemotherapy, and nephrectomy would have been detrimental. It is important to remember that, rarely, other types of cancer arise from the kidney which are not derived from the renal tubular epithelium. These may be suspected if an atypical pattern of metastases or unusual invasion of surrounding organs is present. A preoperative or intraoperative biopsy may be helpful in these cases.
