(BMJ)—A man in his 80s with hx of adenocarcinoma of the rectum treated with surgery and chemo 2 years prior had a painless, enlarging lump in his R groin for 12 months. He had declined post-op surveillance. Exam: irreducible lesion eroded through skin. What’s the dx?
Lymphangioma
Tubercular abscess
Lymphogranuloma venereum
Inguinal lymph node metastases
Incarcerated hernia
You are correct. CT confirmed the dx of inguinal lymph node metastases from a locally recurrent malignancy that had involved the pelvic wall and had also spread to the liver and lungs. Inguinal lymph nodes aren't regional for rectal CA but can be affected if the tumor invades the anal canal or the pelvic sidewall, as occurred in this patient.

The patient received supportive management for sx relief.

BMJ 2023;380:e071080