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Fatal Pulmonary Embolus from Ischemic Necrosis of Intracaval Tumor Thrombus: A Case Report
0022-534 7/93/1505-1492$03.00/0
Vol. 150, 1492-1495, November 1993 Printed in U. S. A.
THE J OURNAL OF UROLOGY Copyright © 1993 by AMERICAN UROLOGICAL ASSOCIATION, INC.
FATAL PULMONARY EMBOLUS FROM ISCHEMIC NECROSIS OF INTRACA VAL TUMOR THROMBUS: A CASE REPORT SCOTT B . JENNINGS, MARK S. AUSTENFELD AND KEVIN BASHAM From the Section of Urologic Surgery, Departments of Surgery and Pathology, University of Kansas Medical Center, Kansas City, Kansas
ABSTRACT Angioinfarction of renal tumors has been proposed as a preoperative adjunct and as palliative therapy. Most side effects of angioinfarction are transient and are well tolerated by the patient. We report a case of fatal pulmonary embolus resulting from migration of an intracaval tumor thrombus following renal arterial embolization. KEY WORD S :
kidney neoplasms; pulmonary embolism; thrombosis; infarction; embolization, therapeutic
Large renal cell carcinomas with extension of tumor into the renal vein or vena cava may be difficult to resect surgically. Angioinfarction of renal tumors was first described in 1969 1 and since that time tumor embolization has been performed with a wide variety of agents. Because the kidney is essentially an end organ, infarction of the renal arterial bed may be accomplished without damage to adjacent vascular systems. Renal angioinfarction has been used as a preoperative adjunct to facilitate resection of large renal cell carcinomas 2 and as palliative therapy in patients not considered to be surgical candidates. 3 Common side effects of angioinfarction include pain, nausea, vomiting, fever and leukocytosis, 4 and these sys temic symptoms are generally easily managed with supportive therapy. More serious complications include renal failure, 5 renal abscess and unplanned embolization of adjacent or distant vascular beds. 6 We present a case of fatal pulmonary embolus arising from ischemic necrosis of an intracaval tumor thrombus. CASE REPORT
An 82-year-old woman presented elsewhere with complaints of right abdominal and hip pain after a fall onto the right side. She was noted to have microscopic hematuria at hospitalization and computerized tomography (CT) showed a large right renal mass with probable extension of tumor thrombus into the inferior vena cava (fig. 1 ) . An inferior venacavogram confirmed the presence of thrombus in the vena cava but could not delineate the cephalad extent of the thrombus (fig. 2). At this Accepted for publication April
30, 1993.
FIG. 2. Inferior venacavogram demonstrates filling defect
FIG. 1. CT scan shows large right renal tumor with probable tumor in inferior vena cava.
point she was transferred to our institution for further evalua tion and treatment. During hospitalization, magnetic resonance imaging of the abdomen showed a large right renal mass with extension of the tumor into the right renal vein and inferior vena cava up to the level of the confluence of the 3 hepatic veins (fig. 3 ) . Because o f the size of the tumor and the extent o f the vena caval thrombus it was elected to angioinfarct the right kidney preoperatively. A renal arteriogram showed a single right renal artery supplying most of the tumor with a large proximal superior capsular branch feeding the remainder of the tumor (fig. 4, A ) . These 2 vessels were embolized with a total of 7 ml.
1492
FATAL PULMONARY EMBOLUS FROM ISCHEMIC NECROSIS O F INTRACAVAL TUMOR THROMBUS
1493
FIG. 3. Magnetic resonance imaging scans. A, coronal view shows right renal mass with tumor extension into right renal vein and inferior vena cava. B, midsagittal view reveals tumor in vena cava to level of hepatic veins.
FIG. 4. A, renal arteriogram demonstrates single right renal artery with proximal branch supplying superior portion of tumor. B, repeat renal arteriogram confirms absence of blood flow distal to occluding coils.
FIG. 5. Representative histological sections from vena caval tumor thrombus and pulmonary emboli. A, section from vena caval tumor thrombus shows pleomorphic cells with variably sized nuclei, prominent nucleoli and abundant cytoplasm. Again, note extensive necrosis. B, section from pulmonary embolus reveals identical histological appearance. H & E, reduced from X250.
1494
FATAL PULM O NARY EMBOLUS FROM ISCHEMIC NECROSIS OF INTRACAVAL TUMOR THROMBUS
FIG. 6. Representative histological sections from vena caval tumor thrombus (A ) and pulmonary emboli (B ) . Note extensive tissue necrosis, although preservation of some cellular details can be appreciated. H & E, reduced from Xl50.
absolute ethanol. The right renal artery was occluded with a balloon catheter proximal to the injection sites to prevent backflow of ethanol into the systemic circulation. Two occlu sion coils were also placed at the first bifurcation of the right renal artery. Repeat arteriography at the end of the procedure confirmed the absence of blood flow in the right renal arterial tree distal to the occluding coils (fig. 4, B ) . Immediately following the procedure the patient did well, with a complaint only of mild abdominal pain. However, ap proximately 18 hours after angioinfarction she became acutely unresponsive with cardiovascular collapse. Despite aggressive resuscitative measures she died 2 hours later. At autopsy a renal cell carcinoma was found in the superior pole of the right kidney with extension of the tumor into the right renal vein and inferior vena cava. Examination of the lungs revealed extensive bilateral pulmonary arterial emboli involving large and small pulmonary arteries. Microscopically, the pulmonary emboli were identical in composition to the vena caval mass. The majority of cells were necrotic, although some cellular details were preserved, consistent with recent infarction (fig. 5). Pleomorphic cells with variably sized nuclei and abundant eosinophilic or pale cytoplasm, consistent with high grade renal cell carcinoma, were seen (fig. 6). The cause of death was acute massive bilateral pulmonary embolization resulting from the dislodgement of thrombotic renal tumor tissue in the inferior vena cava. DISCUSSION
Renal artery embolization has been used preoperatively in preparation for nephrectomy and as a palliative measure for unresectable tumors causing significant pain or hematuria. 3 Putative advantages of embolization include decreased blood loss at operation, 7 enhancement of perinephric tissue planes, 3 • greater immunogenic response to the tumor, 8 and improvement of nutritional status and anemia. 9 In addition, preoperative angioinfarction has been proposed for large tumors in which the renal artery may be difficult to expose. ° Complications of renal artery embolization include the "post-infarction syn drome" 5 consisting of ileus, fever, flank pain and leukocytosis, as well as infarction of the bowel or lower extremities from leakage of the embolization material, migration of mechanical embolization agents and injury to the contralateral kidney from use of contrast materials. 3 • 6 Because the blood supply of tumor extension into the renal vein and vena cava is derived primarily from the ipsilateral renal artery, 1 1 angioinfarction carries the theoretical risk of ischemic necrosis of the tumor thrombus causing pulmonary embolus. To our knowledge this has not been reported previously in the literature. It is conceivable that massive pulmonary embolism would have occurred in this case without prior renal infarction. There is a report in the literature of a patient who presented with a massive pulmonary embolus as the initial manifestation of a large renal cell carcinoma with extension of tumor into the 4
1
vena cava. In a large autopsy series tumor emboli in the lungs were found in 31 % of the patients with renal cell carcinoma but these were not believed to be the primary cause of death in any of these patients. 3 It is unclear from this report how many of these patients underwent some form of tumor manipulation before death. Numerous other investigators have documented massive malignant pulmonary embolus as an intraoperative cause of morbidity or mortality. 4- 0 These patients all under went surgical or anesthetic manipulation before manifestation of the pulmonary embolus. Others have not documented the occurrence of post-infarc tion pulmonary emboli in patients undergoing preoperative or palliative embolization of renal tumors. Craven et al reported on 3 patients with intracaval extension of tumor who under went renal embolization followed by nephrectomy and removal of tumor thrombus through an inferior venacavotomy. 9 All 3 of these patients demonstrated a decrease in size of the intracaval tumor extension following renal embolization. Other investi gators have performed successful embolization in patients with intracaval tumor extension but no mention was made of the fate of the intracaval thrombus. • It is possible that pulmonary emboli from intracaval thrombi occur more frequently but are clinically silent or insignificant. Alternatively, the tumor thrombus may be nonvascularized or may receive its blood supply via diapedesis of vena caval blood or neovascularization from adjacent arteries and, thus, would not be affected by angioinfarction of the main renal artery. In conclusion, although we cannot definitively state that the fatal pulmonary embolus in our patient was due solely to ischemic necrosis of the intracaval tumor thrombus caused by angioinfarction, the clinical course and pathological findings support this sequence of events. Although uncommon, this complication must be considered before the infarction of any renal mass extending into the renal vein or vena cava. 12
1
1
2
4 21
REFERENCES
1. Lalli, A. F., Peterson, N. and Bookstein, J. J.: Roentgen-guided infarctions of kidneys and lungs. A potential therapeutic technic. Radiology, 93: 434, 1969. 2. Mebust, W. K., Weigel, J. W., Lee, K. R., Cox, G. G., Jewell, W. R. and Krishnan, E. C.: Renal cell carcinoma-angioinfarction. J. Urol., 1 3 1 : 231, 1984. 3. McLean, G. K. and Meranze, S. G.: Embolization techniques in the urinary tract. Urol. Clin. N. Amer., 1 2 : 743, 1985. 4. Wallace, S., Chuang, V. P., Swanson, D., Bracken, B., Hersh, E. M., Ayala, A. and Johnson, D.: Embolization of renal carcinoma. Radiology, 138: 563, 1981. 5. Chuang, V. P., Wallace, S. and Swanson, D. A.: Technique and complications of renal carcinoma infarction. Urol. Rad., 2: 223, 1981. 6. Cox, G. G., Lee, K. R., Price, H. I., Gunter, K., Noble, M. J. and Mebust, W. K.: Colonic infarction following ethanol emboliza tion of renal-cell carcinoma. Radiology, 145: 343, 1982. 7. Singsaas, M. W., Chopp, R. T. and Mendez, R.: Preoperative renal
FATAL P U L M O NARY EMBOLUS FROM ISCH EMIC NECROS IS OF INTRACAVAL TUJV WR THROMBUS
8. 9. 10.
11.
12. 13.
embolization as adjunct t o radical nephrectomy. Urology, lLJ,: 1, 1979. Swanson, D. A., Wallace, S. and Johnson, D. E.: The role of embolization and nephrectomy in the treatment of metastatic renal carcinoma. Urol. Clin. N. Amer. , 7: 719, 1980. Craven, W. M., Redmond, P. L., Kumpe, D. A., Durham, J. D. and Wettlaufer, J. N.: Planned delayed nephrectomy after ethanol embolization of renal c arcinoma. J. Urol., 146: 704, 1991 . Williams, R. D . : Renal, perirenal, and ureteral neoplasms. I n : Adult and Pediatric Urology. Edited by J. Y. Gillenwater, J. T. Grayhack, S. S. Howards and J. D. Duckett. St. Louis: Mosby Year Book, Inc., vol. 1 , chapt. 16, pp. 571-614, 199 1 . Pritchett, T. R., Lieskovsky, G. and Skinner, D. G . : Clinical man ifestations and treatment of renal parenchymal tumors. In: Di agnosis and Management of Genitourinary Cancer. Edited by D. G. Skinner and G. Lieskovsky. Philadelphia: W. B. Saunders Co., chapt. 19, pp. 337-361, 1988. Novick, A. C., Daughtry, J. D., Stewart, B. H. and Groves, L. R.: Pulmonary embolus presenting as initial manifestation of renal cell carcinoma. Urology, 1 2 : 707, 1978. Winterbauer, R. H., Elfenbein, I. B. and Ball, W. C., Jr. : Incidence
14. 15. 16. 17. 18. 19. 20. 21.
1495
and clinical significance of tumor embolization to the lungs. Amer. J. Med., 45: 271, 1968. Mimpriss, T. W. and Birt, St. J. M. C.: Sudden death at operation due to tumour embolus. Brit. J. Surg. , 36: 429, 1949. Masson, A. H. B. and Branwood, A. W.: Sudden operative death due to tumor embolism. Brit. Med. J., 1: 1514, 1955. Yates, H.: Sudden operative death due to tumor embolism. Brit. Med. J., 2: 202, 1956. Milne, B., Cervenka, F. W., Morales, A. and Salemo, T. A.: Massive intraoperative pulmonary tumor embolus from renal cell carci noma. Anesthesiology, 54: 253, 1981. Wilkinson, C. J., Kimovec, M. A. and Uejima, T.: Cardiopulmonary bypass in patients with malignant renal neoplasms. Brit. J. Anaesth. , 58: 461, 1986. Markham, N. I. and Doyle, P. T.: Prolonged survival following emergency pulmonary tumour embolectomy and subsequent ne phrectomy. Brit. J. Urol., 59: 484, 1987. Henriksson, C., Aldenborg, F., Lindberg, S. and Pettersson, S.: Pulmonary embolism in renal cell carcinoma with vena cava extension. Scand. J. Urol. Nephrol., 22: 215, 1988. Leinonen, A.: Embolization of renal carcinoma. Comparison be tween the early results of Gelfoam and absolute ethanol embo lization. Ann. Clin. Res., 17: 299, 1985.
Vol. 150, 1492-1495, November 1993 Printed in U. S. A.
THE J OURNAL OF UROLOGY Copyright © 1993 by AMERICAN UROLOGICAL ASSOCIATION, INC.
FATAL PULMONARY EMBOLUS FROM ISCHEMIC NECROSIS OF INTRACA VAL TUMOR THROMBUS: A CASE REPORT SCOTT B . JENNINGS, MARK S. AUSTENFELD AND KEVIN BASHAM From the Section of Urologic Surgery, Departments of Surgery and Pathology, University of Kansas Medical Center, Kansas City, Kansas
ABSTRACT Angioinfarction of renal tumors has been proposed as a preoperative adjunct and as palliative therapy. Most side effects of angioinfarction are transient and are well tolerated by the patient. We report a case of fatal pulmonary embolus resulting from migration of an intracaval tumor thrombus following renal arterial embolization. KEY WORD S :
kidney neoplasms; pulmonary embolism; thrombosis; infarction; embolization, therapeutic
Large renal cell carcinomas with extension of tumor into the renal vein or vena cava may be difficult to resect surgically. Angioinfarction of renal tumors was first described in 1969 1 and since that time tumor embolization has been performed with a wide variety of agents. Because the kidney is essentially an end organ, infarction of the renal arterial bed may be accomplished without damage to adjacent vascular systems. Renal angioinfarction has been used as a preoperative adjunct to facilitate resection of large renal cell carcinomas 2 and as palliative therapy in patients not considered to be surgical candidates. 3 Common side effects of angioinfarction include pain, nausea, vomiting, fever and leukocytosis, 4 and these sys temic symptoms are generally easily managed with supportive therapy. More serious complications include renal failure, 5 renal abscess and unplanned embolization of adjacent or distant vascular beds. 6 We present a case of fatal pulmonary embolus arising from ischemic necrosis of an intracaval tumor thrombus. CASE REPORT
An 82-year-old woman presented elsewhere with complaints of right abdominal and hip pain after a fall onto the right side. She was noted to have microscopic hematuria at hospitalization and computerized tomography (CT) showed a large right renal mass with probable extension of tumor thrombus into the inferior vena cava (fig. 1 ) . An inferior venacavogram confirmed the presence of thrombus in the vena cava but could not delineate the cephalad extent of the thrombus (fig. 2). At this Accepted for publication April
30, 1993.
FIG. 2. Inferior venacavogram demonstrates filling defect
FIG. 1. CT scan shows large right renal tumor with probable tumor in inferior vena cava.
point she was transferred to our institution for further evalua tion and treatment. During hospitalization, magnetic resonance imaging of the abdomen showed a large right renal mass with extension of the tumor into the right renal vein and inferior vena cava up to the level of the confluence of the 3 hepatic veins (fig. 3 ) . Because o f the size of the tumor and the extent o f the vena caval thrombus it was elected to angioinfarct the right kidney preoperatively. A renal arteriogram showed a single right renal artery supplying most of the tumor with a large proximal superior capsular branch feeding the remainder of the tumor (fig. 4, A ) . These 2 vessels were embolized with a total of 7 ml.
1492
FATAL PULMONARY EMBOLUS FROM ISCHEMIC NECROSIS O F INTRACAVAL TUMOR THROMBUS
1493
FIG. 3. Magnetic resonance imaging scans. A, coronal view shows right renal mass with tumor extension into right renal vein and inferior vena cava. B, midsagittal view reveals tumor in vena cava to level of hepatic veins.
FIG. 4. A, renal arteriogram demonstrates single right renal artery with proximal branch supplying superior portion of tumor. B, repeat renal arteriogram confirms absence of blood flow distal to occluding coils.
FIG. 5. Representative histological sections from vena caval tumor thrombus and pulmonary emboli. A, section from vena caval tumor thrombus shows pleomorphic cells with variably sized nuclei, prominent nucleoli and abundant cytoplasm. Again, note extensive necrosis. B, section from pulmonary embolus reveals identical histological appearance. H & E, reduced from X250.
1494
FATAL PULM O NARY EMBOLUS FROM ISCHEMIC NECROSIS OF INTRACAVAL TUMOR THROMBUS
FIG. 6. Representative histological sections from vena caval tumor thrombus (A ) and pulmonary emboli (B ) . Note extensive tissue necrosis, although preservation of some cellular details can be appreciated. H & E, reduced from Xl50.
absolute ethanol. The right renal artery was occluded with a balloon catheter proximal to the injection sites to prevent backflow of ethanol into the systemic circulation. Two occlu sion coils were also placed at the first bifurcation of the right renal artery. Repeat arteriography at the end of the procedure confirmed the absence of blood flow in the right renal arterial tree distal to the occluding coils (fig. 4, B ) . Immediately following the procedure the patient did well, with a complaint only of mild abdominal pain. However, ap proximately 18 hours after angioinfarction she became acutely unresponsive with cardiovascular collapse. Despite aggressive resuscitative measures she died 2 hours later. At autopsy a renal cell carcinoma was found in the superior pole of the right kidney with extension of the tumor into the right renal vein and inferior vena cava. Examination of the lungs revealed extensive bilateral pulmonary arterial emboli involving large and small pulmonary arteries. Microscopically, the pulmonary emboli were identical in composition to the vena caval mass. The majority of cells were necrotic, although some cellular details were preserved, consistent with recent infarction (fig. 5). Pleomorphic cells with variably sized nuclei and abundant eosinophilic or pale cytoplasm, consistent with high grade renal cell carcinoma, were seen (fig. 6). The cause of death was acute massive bilateral pulmonary embolization resulting from the dislodgement of thrombotic renal tumor tissue in the inferior vena cava. DISCUSSION
Renal artery embolization has been used preoperatively in preparation for nephrectomy and as a palliative measure for unresectable tumors causing significant pain or hematuria. 3 Putative advantages of embolization include decreased blood loss at operation, 7 enhancement of perinephric tissue planes, 3 • greater immunogenic response to the tumor, 8 and improvement of nutritional status and anemia. 9 In addition, preoperative angioinfarction has been proposed for large tumors in which the renal artery may be difficult to expose. ° Complications of renal artery embolization include the "post-infarction syn drome" 5 consisting of ileus, fever, flank pain and leukocytosis, as well as infarction of the bowel or lower extremities from leakage of the embolization material, migration of mechanical embolization agents and injury to the contralateral kidney from use of contrast materials. 3 • 6 Because the blood supply of tumor extension into the renal vein and vena cava is derived primarily from the ipsilateral renal artery, 1 1 angioinfarction carries the theoretical risk of ischemic necrosis of the tumor thrombus causing pulmonary embolus. To our knowledge this has not been reported previously in the literature. It is conceivable that massive pulmonary embolism would have occurred in this case without prior renal infarction. There is a report in the literature of a patient who presented with a massive pulmonary embolus as the initial manifestation of a large renal cell carcinoma with extension of tumor into the 4
1
vena cava. In a large autopsy series tumor emboli in the lungs were found in 31 % of the patients with renal cell carcinoma but these were not believed to be the primary cause of death in any of these patients. 3 It is unclear from this report how many of these patients underwent some form of tumor manipulation before death. Numerous other investigators have documented massive malignant pulmonary embolus as an intraoperative cause of morbidity or mortality. 4- 0 These patients all under went surgical or anesthetic manipulation before manifestation of the pulmonary embolus. Others have not documented the occurrence of post-infarc tion pulmonary emboli in patients undergoing preoperative or palliative embolization of renal tumors. Craven et al reported on 3 patients with intracaval extension of tumor who under went renal embolization followed by nephrectomy and removal of tumor thrombus through an inferior venacavotomy. 9 All 3 of these patients demonstrated a decrease in size of the intracaval tumor extension following renal embolization. Other investi gators have performed successful embolization in patients with intracaval tumor extension but no mention was made of the fate of the intracaval thrombus. • It is possible that pulmonary emboli from intracaval thrombi occur more frequently but are clinically silent or insignificant. Alternatively, the tumor thrombus may be nonvascularized or may receive its blood supply via diapedesis of vena caval blood or neovascularization from adjacent arteries and, thus, would not be affected by angioinfarction of the main renal artery. In conclusion, although we cannot definitively state that the fatal pulmonary embolus in our patient was due solely to ischemic necrosis of the intracaval tumor thrombus caused by angioinfarction, the clinical course and pathological findings support this sequence of events. Although uncommon, this complication must be considered before the infarction of any renal mass extending into the renal vein or vena cava. 12
1
1
2
4 21
REFERENCES
1. Lalli, A. F., Peterson, N. and Bookstein, J. J.: Roentgen-guided infarctions of kidneys and lungs. A potential therapeutic technic. Radiology, 93: 434, 1969. 2. Mebust, W. K., Weigel, J. W., Lee, K. R., Cox, G. G., Jewell, W. R. and Krishnan, E. C.: Renal cell carcinoma-angioinfarction. J. Urol., 1 3 1 : 231, 1984. 3. McLean, G. K. and Meranze, S. G.: Embolization techniques in the urinary tract. Urol. Clin. N. Amer., 1 2 : 743, 1985. 4. Wallace, S., Chuang, V. P., Swanson, D., Bracken, B., Hersh, E. M., Ayala, A. and Johnson, D.: Embolization of renal carcinoma. Radiology, 138: 563, 1981. 5. Chuang, V. P., Wallace, S. and Swanson, D. A.: Technique and complications of renal carcinoma infarction. Urol. Rad., 2: 223, 1981. 6. Cox, G. G., Lee, K. R., Price, H. I., Gunter, K., Noble, M. J. and Mebust, W. K.: Colonic infarction following ethanol emboliza tion of renal-cell carcinoma. Radiology, 145: 343, 1982. 7. Singsaas, M. W., Chopp, R. T. and Mendez, R.: Preoperative renal
FATAL P U L M O NARY EMBOLUS FROM ISCH EMIC NECROS IS OF INTRACAVAL TUJV WR THROMBUS
8. 9. 10.
11.
12. 13.
embolization as adjunct t o radical nephrectomy. Urology, lLJ,: 1, 1979. Swanson, D. A., Wallace, S. and Johnson, D. E.: The role of embolization and nephrectomy in the treatment of metastatic renal carcinoma. Urol. Clin. N. Amer. , 7: 719, 1980. Craven, W. M., Redmond, P. L., Kumpe, D. A., Durham, J. D. and Wettlaufer, J. N.: Planned delayed nephrectomy after ethanol embolization of renal c arcinoma. J. Urol., 146: 704, 1991 . Williams, R. D . : Renal, perirenal, and ureteral neoplasms. I n : Adult and Pediatric Urology. Edited by J. Y. Gillenwater, J. T. Grayhack, S. S. Howards and J. D. Duckett. St. Louis: Mosby Year Book, Inc., vol. 1 , chapt. 16, pp. 571-614, 199 1 . Pritchett, T. R., Lieskovsky, G. and Skinner, D. G . : Clinical man ifestations and treatment of renal parenchymal tumors. In: Di agnosis and Management of Genitourinary Cancer. Edited by D. G. Skinner and G. Lieskovsky. Philadelphia: W. B. Saunders Co., chapt. 19, pp. 337-361, 1988. Novick, A. C., Daughtry, J. D., Stewart, B. H. and Groves, L. R.: Pulmonary embolus presenting as initial manifestation of renal cell carcinoma. Urology, 1 2 : 707, 1978. Winterbauer, R. H., Elfenbein, I. B. and Ball, W. C., Jr. : Incidence
14. 15. 16. 17. 18. 19. 20. 21.
1495
and clinical significance of tumor embolization to the lungs. Amer. J. Med., 45: 271, 1968. Mimpriss, T. W. and Birt, St. J. M. C.: Sudden death at operation due to tumour embolus. Brit. J. Surg. , 36: 429, 1949. Masson, A. H. B. and Branwood, A. W.: Sudden operative death due to tumor embolism. Brit. Med. J., 1: 1514, 1955. Yates, H.: Sudden operative death due to tumor embolism. Brit. Med. J., 2: 202, 1956. Milne, B., Cervenka, F. W., Morales, A. and Salemo, T. A.: Massive intraoperative pulmonary tumor embolus from renal cell carci noma. Anesthesiology, 54: 253, 1981. Wilkinson, C. J., Kimovec, M. A. and Uejima, T.: Cardiopulmonary bypass in patients with malignant renal neoplasms. Brit. J. Anaesth. , 58: 461, 1986. Markham, N. I. and Doyle, P. T.: Prolonged survival following emergency pulmonary tumour embolectomy and subsequent ne phrectomy. Brit. J. Urol., 59: 484, 1987. Henriksson, C., Aldenborg, F., Lindberg, S. and Pettersson, S.: Pulmonary embolism in renal cell carcinoma with vena cava extension. Scand. J. Urol. Nephrol., 22: 215, 1988. Leinonen, A.: Embolization of renal carcinoma. Comparison be tween the early results of Gelfoam and absolute ethanol embo lization. Ann. Clin. Res., 17: 299, 1985.