TY - JOUR AU - Suresh Tharmaradinam AU - Selliah Kanthan AU - Dana Diudea AU - Rani Kanthan PY - 2022 DA - 2022/12/01 TI - Uncommon Mucosal Metastases in Endoscopic Colorectal Biopsies: A 20-year Single-Institution Review of 55,154 Consecutive Endoscopic Colorectal Biopsies JO - Gastroenterology Hepatology and Digestive System VL - 1 IS - 2 AB - Background: Colorectal endoscopic biopsies are the commonest biopsy specimens in surgical pathology practice with the implementation of screening colonoscopy to detect early colorectal cancer. Aim: The aim of this study was to examine the frequency of non-colonic mucosal metastases to their primary site of origin and their identification in endoscopic colorectal biopsies. Design: Recent identification of four endoscopic biopsies with mucosal metastases from breast, lung, merkel cell and endometrium resulted in a 20-year computerized data search of biopsies with the diagnosis of colon/rectum and breast/lung/Merkel/endometrial/prostate/ovary/urothelial/melanoma/ renal/thyroid”. Non-endoscopic biopsies from laparoscopy/laparotomy/autopsy were excluded. Studyselected cases were reviewed with their original malignancy in the context of clinical history with review of relevant literature. Results: 52 cases ~0.4% of non-colonic mucosal metastases were recognized from 13,564 malignant biopsies of 55,154 colorectal mucosal biopsies. The primary sites of origin identified using immunohistochemical markers were: Prostate-17 cases~33%, Ovary-12 cases~23%, Breast and Urothelial-7 each~13%, Lung, Renal, Endometrial-2 each~4%, Merkel Cell Carcinoma, Malignant Melanoma, Thyroid-1 each~2% ; thus 27% were extra-pelvic in origin. They were predominant in males (29) than females (23) with equal distribution in colonic and rectal biopsies. The average disease interval between the original malignancy and endoscopic colorectal metastases was 7yrs. Conclusions: Although primary colorectal carcinoma is the commonest malignant diagnosis of colorectal endoscopic biopsies, malignancies from non-colonic organs, though uncommon, can present as mucosal metastases, often with delayed intervals. Familiarity and awareness of these uncommon metastases is vital for accurate pathological diagnosis, aided by newer immunohistochemical markers. Such precise information is critical for judicious triaging in planning further patient management. SN - 2833-4418 UR - https://dx.doi.org/10.33425/2833-4418.0007 DO - 10.33425/2833-4418.0007