case_images: PMC11658880_01
case_images: Magnetic resonance image of the rectum demonstrating annular thickening of the mid to upper rectum starting 7.5cm above the anal verge with linear T2 signal suggesting mucinous component
case_images: rcsann.2023.0023.01.jpg
case_images: PMC11658880_01_rcsann.2023.0023.01.jpg
case_images: rcsann.2023.0023F1
case_images: Magnetic resonance imaging (MRI) of the rectum demonstrated annular thickening of the mid to upper rectum starting 7.5cm above the anal verge, with minor stranding of the serosa and mesorectal fat but no significant lymphadenopathy (Figure 1).
case_images: Histological specimens from Case 1
case_images: rcsann.2023.0023.02.jpg
case_images: PMC11658880_01_rcsann.2023.0023.02.jpg
case_images: rcsann.2023.0023F2
case_images: Histology from the rectum demonstrated metastatic gastric adenocarcinoma in the rectum and pericolonic fat, which was present at the distal resection margin and circumferential resection margin (Figure 2).
case_images: PMC11658880_02
case_images: (a) Diffuse circumferential thickening involving the anal canal and entire rectum with surrounding inflammation in mesorectal fat and multiple tiny mesorectal lymph nodes. (b) A 12mm high T2 signal in left posterior anal canal suspicious for small collection (yellow arrow). Overall appearances favour ano-proctitis; however, underlying malignancy cannot be excluded.
case_images: rcsann.2023.0023.03.jpg
case_images: PMC11658880_02_rcsann.2023.0023.03.jpg
case_images: rcsann.2023.0023F3
case_images: There was a palpable nodularity on rectal examination, so MRI rectum was performed showing diffuse circumferential rectal thickening involving the anal canal and entire rectum with surrounding inflammatory stranding and multiple tiny lymph nodes in the mesorectum (Figure 3).
case_images: Histological specimens from case 2
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case_images: PMC11658880_02_rcsann.2023.0023.04.jpg
case_images: rcsann.2023.0023F4
case_images: Biopsy showed metastatic poorly differentiated adenocarcinoma that appeared to arise from lymphovascular invasion suggestive of gastric origin (Figure 4).