(10) A 63-year old man recently-diagnosed with kidney cancer presents to your clinic reporting the new onset of painless swelling of his left scrotum. On examination, you find that the swelling is caused by engorged spermatic veins around the left testis. His right testis and scrotum are normal. This new physical finding suggests that his kidney cancer has spread to the:
Explanation
Correct Answer:
Renal vein
Take-Home Message:
The venous drainage of the right and left testes is different (outlined in yellow in the image below): the left testis drains into the left renal vein while the right testis drains directly into the IVC. Obstruction of the left renal vein (e.g. from a renal tumor) can cause rapid engorgement of the spermatic veins around the left testis (termed a varicocele).
Explanation of Correct Answer:
The testes receive their arterial supply from the gonadal arteries, which ariase from the anterior surface of the abdominal aorta near its midpoint. The right gonadal vein, which drains the testis and its coverings, travels up from the scrotum through the inguinal canal and into the abdominal cavity in company with the right gonadal artery, draining into the inferior vena cava near the level of the renal vessels. However, the left gonadal vein has a slightly different course, initially traveling with the gonadal artery but draining into the left renal vein rather than the cava. So, if a tumor involves the left renal vein, as renal cell carcinomas may sometimes do, this will typically block the drainage from the left testis and scrotum, causing engorgement of the veins in this area.
Explanation of Incorrect Answers:
Spread of tumor to the abdominal aorta could compromise the gonadal artery but would not cause backup of venous blood in the scrotum.
Spread to the spermatic artery would not result in enlarged vessels in the scrotum, but might cause testicular infarction.
Spread to the inferior vena cava would be unlikely to block selectively the left gonadal venous drainage although it might block drainage of the right testis which drains into the IVC, depending on the location involved.
Spread to the inferior mesenteric vein would likely be asymptomatic, or might cause GI symptoms but would not interfere with venous drainage from the scrotum.
Spread to the testis would not cause venous blockage.
Clinical Pearls:
(1) Lymphatic drainage of the testis follows venous drainage, so that metastases to nodes from testicular carcinomas first appear near the level of the renal vessels, where both gonadal veins drain (on the right directly into the IVC and on the left into the left renal vein).
(2) If a unilateral left varicocele develops in one of your patients, a left renal tumor needs to be ruled out by radiologic imaging.
For more information on this topic, please click on the following link(s):
(While these web sources have been vetted by our content experts, please use them with caution --- the peer-reviewed literature should be the ultimate source of medical information.)
http://www.emedicine.com/radio/topic601.htm
Reference:
Curti BD. Renal cell carcinoma. JAMA 2004; 292:97-100.
Renal vein
Take-Home Message:
The venous drainage of the right and left testes is different (outlined in yellow in the image below): the left testis drains into the left renal vein while the right testis drains directly into the IVC. Obstruction of the left renal vein (e.g. from a renal tumor) can cause rapid engorgement of the spermatic veins around the left testis (termed a varicocele).
Explanation of Correct Answer:
The testes receive their arterial supply from the gonadal arteries, which ariase from the anterior surface of the abdominal aorta near its midpoint. The right gonadal vein, which drains the testis and its coverings, travels up from the scrotum through the inguinal canal and into the abdominal cavity in company with the right gonadal artery, draining into the inferior vena cava near the level of the renal vessels. However, the left gonadal vein has a slightly different course, initially traveling with the gonadal artery but draining into the left renal vein rather than the cava. So, if a tumor involves the left renal vein, as renal cell carcinomas may sometimes do, this will typically block the drainage from the left testis and scrotum, causing engorgement of the veins in this area.
Explanation of Incorrect Answers:
Spread of tumor to the abdominal aorta could compromise the gonadal artery but would not cause backup of venous blood in the scrotum.
Spread to the spermatic artery would not result in enlarged vessels in the scrotum, but might cause testicular infarction.
Spread to the inferior vena cava would be unlikely to block selectively the left gonadal venous drainage although it might block drainage of the right testis which drains into the IVC, depending on the location involved.
Spread to the inferior mesenteric vein would likely be asymptomatic, or might cause GI symptoms but would not interfere with venous drainage from the scrotum.
Spread to the testis would not cause venous blockage.
Clinical Pearls:
(1) Lymphatic drainage of the testis follows venous drainage, so that metastases to nodes from testicular carcinomas first appear near the level of the renal vessels, where both gonadal veins drain (on the right directly into the IVC and on the left into the left renal vein).
(2) If a unilateral left varicocele develops in one of your patients, a left renal tumor needs to be ruled out by radiologic imaging.
For more information on this topic, please click on the following link(s):
(While these web sources have been vetted by our content experts, please use them with caution --- the peer-reviewed literature should be the ultimate source of medical information.)
http://www.emedicine.com/radio/topic601.htm
Reference:
Curti BD. Renal cell carcinoma. JAMA 2004; 292:97-100.
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