A 58-year-old postmenopausal woman is diagnosed with carcinoma of the distal gastrointestinal tract. During surgery lymph nodes from the sacral, internal iliac, and inguinal lymph node groups were removed and sent for histopathologic examination. The pathology report revealed positive cancerous cells only at the inguinal lymph nodes. Which of the following parts of the gastrointestinal tract were most likely affected?
Lymph from the cutaneous portion of the anal canal (below the pectinate line) drains into the inguinal nodes. Lymph from most parts of the rectum and from the mucosal zone of the anal canal (above the pectinate line) drains into the internal iliac nodes. Lymph from some parts of the rectum also drains into the sacral nodes.
Cutaneous portion of anal canal
Distal rectum
Mucosal zone of anal canal
Pectinate line of anal canal
Abdomen & Pelvis