Lateral pelvic node dissection after neoadjuvant chemoradiation in rectal cancer with right internal iliac node metastasis but without regional node metastasis: A case report

INTRODUCTION AND IMPORTANCE: Total mesorectal excision (TME) with lateral pelvic node dissection was routinely done in low clinical T3 rectal tumors below the peritoneal reflection as stated in the Japanese guidelines for colorectal cancer. Our institution follows the same practice in selected patients. This is our first reported case wherein a patient with rectal cancer underwent total mesorectal excision with lateral lymphadenectomy after neoadjuvant treatment with a positive lateral node on histopathology. CASE PRESENTATION: A 49 year old female rectal had rectal adenocarcinoma 4 cm FAV. Pelvic MRI revealed a low rectal tumor abutting the mesorectal fascia anteriorly, anal sphincters not involved, and confluent enlarged right iliac nodes. After neoadjuvant treatment, interval decrease in size of the rectal lesion and the right iliac nodes were noted. Patient underwent partial intersphincteric resection, lateral pelvic node dissection and protective loop ileostomy. CLINICAL DISCUSSION: Histopathology revealed a rectal adenocarcinoma with one right internal iliac lymph node was positive for tumor involvement. Circumferential resection margin was 4.0 mm. Patient is currently on 4th cycle of adjuvant chemotherapy. Preoperative chemoradiation could not completely eradicate lateral pelvic node metastasis. Therefore, lateral pelvic node dissection should be considered if lateral pelvic lymph node metastasis is suspected even after neoadjuvant therapy. CONCLUSION: Unlike TME, performance of a routine lateral lymphadenectomy in rectal cancer surgery varies by geographic location. Reports from Asian countries and our practice in our institution shows that it can be performed safely. This could improve the oncologic outcomes of patients especially if combined with neoadjuvant chemoradiotherapy.