Inguinal Lymph Node Metastasis from a Sigmoid Stomal Cancer: A Case Report

Inguinal lymph node metastasis from colon adenocarcinoma is extremely rare. Cancer arising from a stoma is relatively rare, and cases with lymph node metastasis including inguinal lymph node metastasis are even rarer. Due to its rarity, there is no established surgical procedure for stomal cancer. Herein, we report a rare case of inguinal lymph node metastasis from a sigmoid stomal cancer, successfully treated by inguinal lymph node dissection.

An 87-year-old man had undergone abdominoperineal resection for rectal cancer when he was aged 28 years. He was referred to our hospital due to complaints of swelling and bleeding from the colostomy. Colonoscopy revealed a hemorrhagic type 2 tumor at the colostomy site. Biopsy revealed a moderately differentiated tubular adenocarcinoma. The diagnosis was adenocarcinoma occurring from a sigmoid colostomy. We performed a laparoscopic sigmoid colectomy with D3 lymph node dissection and colostomy reconstruction. The pathological stage was pT2N0M0 (pStage I). Contrast-enhanced CT performed 6 months postoperatively demonstrated enlargement of the previously noted left inguinal lymph node. Left inguinal lymph node dissection was performed because inguinal lymph node metastasis from sigmoid stomal cancer was suspected. Histopathological examination revealed moderately differentiated tubular adenocarcinoma. Because the histological features resembled those of the primary stomal cancer, the lesion was diagnosed as inguinal lymph node metastasis from sigmoid stomal cancer. Twenty-two months after the surgery, he has survived without recurrence.

This case represents the first reported case of inguinal lymph node metastasis from a sigmoid stomal cancer without abdominal wall or skin invasion. Altered lymphatic drainage associated with long-standing stoma construction may have contributed to the development of inguinal lymph node metastasis, which might be treated by inguinal lymph node dissection.