Question

A known case of anal carcinoma with mass near the anal opening comes for follow-up. Which of the following lymph nodes are most likely involved?

• A. Superficial inguinal lymph nodes
• B. Deep inguinal lymph nodes
• C. External iliac lymph nodes
• D. Internal iliac lymph nodes

Hint:

Anal canal below pectinate line and perianal region drain to superficial inguinal lymph nodes.

Answer 1

The Correct Option is A

Concept: Lymphatic drainage of the anal canal depends on the location relative to the pectinate line. Lesions near the anal opening or below the pectinate line commonly drain to superficial inguinal lymph nodes.

Step 1: Identify tumor location.
The mass is near the anal opening, which suggests involvement of the lower anal canal or perianal region.

Step 2: Recall lymphatic drainage.
Below the pectinate line, lymph drains mainly to: \[ \text{Superficial inguinal lymph nodes} \]

Step 3: Select the most likely nodes.
Therefore, anal carcinoma near the anal opening most likely involves: \[ \text{Superficial inguinal lymph nodes} \] Therefore, the correct answer is Superficial inguinal lymph nodes.