case_images: PMC11729381_01
case_images: Colonoscopic findings an ulceroproliferative growth visualized in the anal canal, extending upto the rectum.
case_images: CNR2-8-e70121-g003.jpg
case_images: PMC11729381_01_CNR2-8-e70121-g003.jpg
case_images: cnr270121-fig-0001
case_images: On colonoscopy, the ulceroproliferative growth was visualized in the anal canal, extending up to the rectum, and multiple biopsies were taken (Figure 1).
case_images: Liver metastases and the ano-rectal growth as visualized in the baseline whole body FDG18 Positron Emission Tomography CT (PET CT).
case_images: CNR2-8-e70121-g002.jpg
case_images: PMC11729381_01_CNR2-8-e70121-g002.jpg
case_images: cnr270121-fig-0002
case_images: Whole-body FDG PET CT showed FDG avid circumferential wall thickening in the distal rectum and anal canal (SUV max-18.5), FDG avid perirectal bilateral external iliac, bilateral inguinal lymph nodes (largest measuring 1.6 x 1.1 cm and SUV max-2.7) with FDG avid hypodense lesions in segment V and VIII of the liver (SUV max 10.3) (Figure 2).
case_images: (A) Haematoxylin and eosin (H&E) stained section from the anal canal growth shows few colonic mucosal glands with dense inflammation, Scale bar = 4 mum, (magnification x40). (B) and (C) Higher magnification shows loss of crypts along with atypical cells arranged singly and in groups within the inflammatory cells (scale bar = 10 mum, magnification x100; scale bar = 20 mum, magnification x200, respectively). (D) These atypical cells show increase nuclear cytoplasmic ratio, hyperchromatic nucleous with prominent nucleoli (scale bar = 40 mum, magnification x400). (E) The tumor cells are positive for HMB45 (scale bar = 20 mum, magnification x200). (F) The tumor cells are positive for Melan A (scale bar = 20 mum, magnification x200).
case_images: CNR2-8-e70121-g004.jpg
case_images: PMC11729381_01_CNR2-8-e70121-g004.jpg
case_images: cnr270121-fig-0003
case_images: Histopathological examination and immunohistochemistry confirmed the diagnosis of malignant melanoma, BRAF V600 negative (Figure 3).
case_images: FDG 18 PET CT images demonstrating persistent complete metabolic remission (at the end of 3 years of follow-up).
case_images: CNR2-8-e70121-g001.jpg
case_images: PMC11729381_01_CNR2-8-e70121-g001.jpg
case_images: cnr270121-fig-0004
case_images: Furthermore, serial images have demonstrated a persistent CMR, with the response for more than 3 years (last followed up in July, 2024) of treatment and counting (Figure 4).