Squamoid morules in the pseudoinvasive foci of colonic polyp morphologically mimic invasive carcinoma.

摘要: Colorectal adenomas can show focal squamous differentiation or squamoid morules. We describe histologic findings of morules in the pseudoinvasive foci colorectal polyps mimicking invasive carcinoma. Five colonic with were collected. Histologic review and immunostains for cytokeratin 5/6, p63, synaptophysin, chromogranin performed on cases Forty-seven consecutive pseudoinvasion, none which showed by histology review, their clinicopathologic features compared containing Cases more frequently occurred younger patients (P=.047) located right colon (P=.027) than those without Diagnosis included tubular/tubulovillous adenoma low-grade (with morules, n=3; versus n=29) high-grade dysplasia (n=2 n=15) sessile serrated (none n=3). Squamoid formed nodules protruding into lumen glandular structures partially replaced adenomatous glands forming a discrete nodule. They also presented as solid nests showing well-formed morular structure around bottom myxoinflammatory stroma. Importantly, often pseudocribriform nest sitting stroma foci. All (n=4) 5/6 positivity p63 negativity Three 1 4 synaptophysin chromogranin, respectively, mimic carcinoma when present Pathologists should be aware presence.