]> 2026-07-31T16:29:02+00:00 WBR0939 0 en Internal iliac lymph nodes The internal iliac lymph nodes drain the rectum above the pectinate line. Superficial inguinal lymph nodes From below the pectinate line, the rectum is drained by the superficial inguinal lymph node. Mediastinal lymph nodes The mediastinal lymph nodes lie in the center of the chest, particularly along the trachea. The mediastinal lymph nodes give rise to the lymphatic ducts, which drain the lymph to the subclavian vein. While seminomas can present as primary tumors in the mediastinum, in this case we know that the primary is in the testes. Thus, we need to only assess the lymphatic drainage of the testes (para-aortic). Mesenteric lymph nodes The mesenteric lymph nodes drain the gut. The superior mesenteric lymph nodes drain all parts of the gut proximal to the sigmoid colon. The inferior mesenteric lymph nodes drain lymph from the sigmoid colon to the rectum (above the pectinate line). Para-aortic lymph nodes The para-aortic lymph nodes drain the testes and the lower gastrointestinal tract. Anatomy William J Gibson (Reviewed by Serge Korjian) A 25-year-old man presents to his primary care physician after he noticed an irregular hard lump in his right testicle. Serum placental alkaline phosphatase and lactate dehydrogenase are elevated and testicular ultrasound demonstrates a hypoechogenic homogeneous intratesticular mass. Which of the following sites would be the most likely first step in metastatic spread of this tumor? E Genitourinary 2020-10-28T02:08:00Z 2459150.5888889 WBR0939