case_images: PMC11130409_01
case_images: Images of colonoscopy on site of the previous rectocolostomy before and after 6 months of immunotherapy (CR, complete response).
case_images: fimmu-15-1369190-g001.jpg
case_images: PMC11130409_01_fimmu-15-1369190-g001.jpg
case_images: f1
case_images: During follow-up care for rectal cancer of a 76-year-old male patient diagnosed in January 2015 and treated with partial rectum amputation and FOLFOX chemotherapy, a new non-pigmented tumor lesion of 15 mm diameter was discovered localized on site of the previous rectocolostomy in June 2020 by colonoscopy (Figure 1A). In March 2021, after four doses of nivolumab, repeated colonoscopy showed a complete response with total remission of the previously polypoid tumor lesion (Figure 1B).
case_images: Histopathological work-up of the polypoid rectal tumor biopsied before start of immunotherapy. Top, overview stained with hematoxylin + eosin (H+E); bottom, H+E and immunohistochemical stainings in higher magnification.
case_images: fimmu-15-1369190-g002.jpg
case_images: PMC11130409_01_fimmu-15-1369190-g002.jpg
case_images: f2
case_images: Histological work-up revealed mucosal melanoma with immunohistochemical positivity of S100, HMB45, melan A and SOX10 (Figure 2).