A 52-year-old man comes to the office for a painless mass in his right groin. He noticed the mass several weeks ago, and it has slowly enlarged. The patient has a history of HIV, for which he takes antiretroviral therapy. He has not had any new sexual partners recently. Temperature is 37.1 C (98.8 F). On examination, several enlarged, hard lymph nodes are palpated in the right inguinal area inferior to the inguinal ligament. An excisional biopsy is performed, and histopathology shows malignant cells. The malignant cells found in this patient most likely originated from which of the following sites?

Question

A 52-year-old man comes to the office for a painless mass in his right groin.  He noticed the mass several weeks ago, and it has slowly enlarged.  The patient has a history of HIV, for which he takes antiretroviral therapy.  He has not had any new sexual partners recently.  Temperature is 37.1 C (98.8 F).  On examination, several enlarged, hard lymph nodes are palpated in the right inguinal area inferior to the inguinal ligament.  An excisional biopsy is performed, and histopathology shows malignant cells.  The malignant cells found in this patient most likely originated from which of the following sites?

Quizplus · Accepted Answer

11ec160b_3585_9144_9249_99c39e77e9e7_MD0001_00 This patient has palpable, firm superficial inguinal lymph nodes. These nodes overlie the femoral nerve, artery, and vein in the femoral triangle, a region bound by the inguinal ligament, sartorius muscle, and adductor longus muscle. The superficial inguinal nodes drain most cutaneous lymph from the umbilicus down, including the external genitalia and anus (below the dentate line). In this patient, metastasis from a malignancy around the orifice of the anal canal most likely explains his inguinal lymphadenopathy. Exceptions to this drainage pattern include the glans penis and skin of the posterior calf (popliteal lymph nodes), which bypass the superficial inguinal nodes to drain into the deep inguinal lymph nodes. (Choice A) Lymph from the superior portion of the bladder drains to the external iliac nodes whereas lymph from the inferior portion of the bladder drains to the internal iliac nodes. (Choice B) Lymph from the prostate drains primarily to the internal iliac nodes. (Choice D) Lymph from the testes parallels the blood supply from the testicular arteries, which arise directly from the abdominal aorta. As such, testicular lymph drains to the abdominal para-aortic (retroperitoneal) lymph nodes. (Choice E) Lymph from the upper third of the rectum drains to the inferior mesenteric lymph nodes. Educational objective: Most of the cutaneous lymph from the umbilicus down, including the anus below the dentate line, drains to the superficial inguinal lymph nodes. Exceptions are the glans penis and posterior calf, which drain to the deep inguinal nodes.

A 52-Year-Old Man Comes to the Office for a Painless