Colonic Adenomatous Polyps Involving Submucosal Lymphoglandular Complexes: A Diagnostic Pitfall.

摘要: Lymphoglandular complexes (LGCs) are lymphoid nodules containing intestinal mucosa, present in close apposition to muscularis mucosae or submucosa. Rarely, colorectal adenomas involve submucosal LGCs, simulating invasive adenocarcinoma with associated aggregates, and presenting a diagnostic pitfall. We aimed identify distinctive histologic features between LGCs true invasion. Seven (tubular/tubulovillous [n=6], including 4 high-grade dysplasia 1 focal intramucosal adenocarcinoma, sessile serrated adenoma [n=1]) were the right (n=5) left colon (n=2). adenocarcinomas (n=3), (n=2), rectum/rectosigmoid Adenomatous glands involving invested lamina propria, showed continuity surface adenoma, well rounded contained within tissue, predominantly lacked classic of "pseudoinvasion." One case herniation pattern carrying mucosae. Adenocarcinomas had at least one following features: infiltrating single cells/small clusters (n=5), poorly formed, fused, irregular solid tumor nests (n=1), desmoplastic reaction intraluminal necrosis lymphovascular invasion (n=1). In contrast, no these features. herniation, but connection was seen. Five extended into submucosa beyond aggregate. conclusion, rare, clinicopathologically distinct form pseudoinvasion that mimics adenocarcinoma; distinguish them well-rounded contour lack clusters, glands, nests, reaction,