case_images: PMC10708909_01
case_images: Radiological examination findings. (A) Representative image showing the colonoscopic view of the colon. (B) MRI findings, with an arrow indicating an enlarged lymph node adjacent to the left iliac artery. MRI findings of a rectal mass in both sagittal (C) and coronal (D) views, as indicated by the arrows.
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case_images: Colonoscopy findings indicated a rectal mass, highlighting the necessity of biopsy for further evaluation ( Figure 1A ). Further imaging studies included abdominal and pelvic magnetic resonance imaging (MRI) ( Figures 1B-D ), which revealed the following results: 1) No significant abnormalities were observed on the plain scan of the upper abdomen; 2) Changes in the lower segment of the rectum were suggestive of a tumor, with a relatively irregular margin, and multiple enlarged lymph nodes adjacent to the left iliac vessels.
case_images: Histopathological findings of rectal mass. (A) HE staining revealed differentiated adenocarcinoma in the rectum. (B-F) The immunohistochemical examination indicated malignant cells immunoreactive for Cam5.2 (B); MLH1 (C); PMS2 (D); MSH2 (E); and MSH6 (F). Magnification 200x.
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case_images: Under hematoxylin and eosin (HE) staining, cells were observed to arrange themselves into tubular or nest-like structures, a distinctive characteristic of rectal adenocarcinoma tumor cells ( Figure 2A ). Immunohistochemistry (IHC) results indicated that cancer cells were positive for Cam5.1, CDX-2, and Ki-67 (70%) ( Figure 2B ). Mismatch repair proteins tested included MLH1 (+), PMS2 (+), MSH2 (+), and MSH16 (+), demonstrating no deficiency in mismatch repair proteins ( Figures 2C-F ).
case_images: Pathological features of cHL components. HE staining (A) demonstrated that cHL component consisted of mixed inflammatory cells and large HRS cells. HRS cells showed positive IHC staining for CD30 (B), CD15 (C), CD20 (D), and PAX-5 (E) and the proliferation rate of Ki-67 was approximately 40% (F). Magnification 200x. MRI, Magnetic resonance imaging; MPC, Multiple primary cancers; HE, Hematoxylin and eosin; IHC, Immunohistochemistry; CRC, Colorectal cancer; IBD, Inflammatory bowel disease; cHL, Hodgkin lymphoma; HRS, Hodgkin and Reed-Sternberg; NCCN, National Comprehensive Cancer Network.
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case_images: HE staining revealed scattered large mononuclear Hodgkin cells and binuclear or multinuclear Reed-Sternberg cells in the background of mixed inflammatory cells ( Figure 3A ). IHC demonstrated positive staining for CD30, CD15, CD20, and PAX5 in the Hodgkin and Reed-Sternberg (HRS) cells ( Figures 3B-E ), as well as decreased expression of Bob-1, and negative expression of CD10 and CyclinD1. The proliferation rate of Ki-67 in the HRS cells was approximately 40% ( Figure 3F ).