WBR0939

Author	PageAuthor::William J Gibson
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Anatomy
Sub Category	SubCategory::Genitourinary
Prompt	[[Prompt::A 25 year-old male presents to his primary care physician after he noticed an irregular lump in his right testicle. Serum placental alkaline phosphatase and lactate dehydrogenase are elevated. A biopsy of the primary lesion demonstrates large cells with a “fried egg” appearance. Which of the following sites would be the most likely next step in metastatic spread of this tumor?]]
Answer A	AnswerA::Internal iliac lymph nodes
Answer A Explanation	AnswerAExp::The internal iliac lymph nodes drain the rectum above the pectinate line.
Answer B	AnswerB::Superficial inguinal lymph nodes
Answer B Explanation	AnswerBExp::From below the pectinate line, the rectum is drained by the superficial inguinal lymph node.
Answer C	AnswerC::Mediastinal lymph nodes
Answer C Explanation	[[AnswerCExp::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).]]
Answer D	AnswerD::Mesenteric lymph nodes
Answer D Explanation	[[AnswerDExp::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).]]
Answer E	AnswerE::Para-aortic lymph nodes
Answer E Explanation	AnswerEExp::The para-aortic lymph nodes drain the testes and the lower gastrointestinal tract.
Right Answer	RightAnswer::E
Explanation	[[Explanation::The patient in this vignette has developed a seminoma, a germ cell tumor of the testes. It is the most common testicular tumor and mainly affects males between the ages of 15 and 35. These tumors are extremely sensitive to chemotherapy and radiation. Seminomas are associated with an excellent prognosis (5-year survival rate ~90%). Histologically, these tumors are known for containing abundant clear to pale pink cytoplasm with prominent nuclei. This combination of features, creates a “Fried-egg” appearance that is a hallmark of seminomas. Because tumors spread via lymphatic vessels, this question asks about the lymphatic drainage of the testicle. Due to the para-aortic embryologic origin of the Wolffian duct, the testes descend from the aorta. The vascular and lymphatic supply of the testes, is therefore tethered to this region. Thus, the testes are drained by the para-aortic lymph nodes. Educational Objective: Testicular cancer will spread via lymphatics to the para-aortic lymph nodes. References: First Aid 2013 page 192 (lymphatic drainage) First Aid 2013 page 536 (seminomas) First Aid 2012 page 222 (lymphatic drainage) First Aid 2012 page 552 (seminomas)]]
Approved	Approved::Yes
Keyword	WBRKeyword::Testicle, WBRKeyword::Testicular, WBRKeyword::Cancer, WBRKeyword::Lymph node, WBRKeyword::Lymph, WBRKeyword::Metastasis
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::