Long-Term Complete Response in Metastatic Poorly-Differentiated Neuroendocrine Rectal Carcinoma with Multimodal Approach. A Case Report

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Introduction: Rectal neuroendocrine carcinomas (NEC) are extremely rare and account for less than 1% of colorectal malignancies.

Aim(s): Due to aggressive growth and rapid metastatic diffusion, early diagnosis and multidisciplinary approach are mandatory.

Materials and methods: On July 2015 a 42 year-old patient arrived to our Emergency Department for rectal bleeding. Colonoscopy showed an ulcerated lesion at 12 cm from the anal verge; biopsies revealed a NEC G3 ki67 90%. MRI, CT and PET scan showed rectal localization and regional nodal involvement, without metastatic disease. He started first-line chemotherapy with Cisplatinum and Etoposide with Progression Disease and worsening of local symptoms after three cycles. Surgery was recommended and the patient underwent an open anterior low rectal resection with terminal colostomy. Histological report confirmed a small-cells NEC pT3N2b, G3, ki67 98%, with negative surgical margins. The first post-operative total-body CT scan showed an early relapse of disease with an 85 mm pelvic lesion. The patient underwent second line chemotherapy with FOLFIRI and 50Gy radiotherapy (RT). On March 2016 CT-PET imaging showed pelvic Complete Response (CR), although pathological interaortocaval lymph-nodes appeared. Because of low sensibility to systemic treatment we proposed a 45Gy radiotherapy on metastatic sites with Progressive Response.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author: Della Torre S

Authors: Lombardi P, Grandi S, Marinelli M, Manara M, Della Torre S,

Keywords: rectal nec, net, chemotherapy, metastatic disease,