Metachronous Isolated Inguinal Lymph Node Metastasis in Rectal Carcinoma

Abstract Rectal cancers presenting with inguinal lymph node metastasis (ILNM) are rare and challenging to treat. The prevalence of ILNM in rectal carcinoma is 0.36%. ILNM can be synchronous (diagnosed within 1 year of primary treatment) or metachronous (diagnosed after 1 year of primary treatment). Metachronous inguinal lymph nodes can present as isolated solitary metastasis or along with other distant metastasis. As per the literature reviewed by us, few cases of metachronous isolated ILNM presenting after 2 years of disease-free interval have been reported to date. Here, we report two cases of mucinous-type rectal adenocarcinoma, presenting with isolated ILNM with a long disease-free interval (>2 years). Both patients were treated with inguinal lymph node dissection and have been scheduled for further treatment with curative intent. No consensus has been formed on the optimal treatment strategy for patients with metachronous isolated ILNM from rectal adenocarcinoma. However, this subset of patients should not be considered as incurable, since surgical treatment has been shown to prolong survival in various studies. Therefore, the possibility of treatment with curative intent should be considered in such patients.