Search

Abstract Background Composite intestinal adenoma-microcarcinoid (CIAM) is a rare colorectal lesion that mostly comprises a conventional adenomatous component with a minute proportion of neuroendocrine (NE) component. Although microcarcinoids are well-recognized in the setting of chronic inflammatory disorders of the gastrointestinal tract, large intestinal microcarcinoids associated with intestinal adenoma are exceedingly rare and their clinicopathologic characteristics are yet to be elucidated. This study was performed to clarify their clinicopathologic characteristics and to review the relevant literature. Methods In total, 24 cases of CIAM in which tumors were excised endoscopically (n = 22) or surgically (n = 2) were retrieved from the Department of Pathology, Daehang Hospital. We analyzed their clinicopathologic characteristics and performed immunohistochemical staining for NE markers to determine their endocrine nature. Results CIAM usually developed in middle-aged and elderly patients, with a mean age of 62.0 years (range, 44–81 years). Thirteen patients were men and 11 were women, indicating a nearly equal sex ratio. Unlike classic carcinoid tumors, CIAMs occurred mostly in the colon (83.3% of cases), particularly in the proximal colon. Histologically, the microcarcinoid component consisted of low-grade NE cells arranged in small nests, glands or cords interspersed with glandular elements or less frequently resembled squamous morules. There was no expansile nodular or organoid growth pattern, which is typical of carcinoid tumors. The microcarcinoids were 1–20 mm in size (mean size, 4.7 mm) and were mostly situated in the basal lamina propria with no submucosal layer involvement; none showed desmoplastic reaction or increased proliferative activity. Follow-up data (mean, 23.1 months) were available for 18 patients; all patients are alive and well. Conclusions To the best of our knowledge, ours is the largest series of patients with CIAM in the English-language literature. Microcarcinoids found in CIAMs appear to show favorable clinical outcomes regardless of their size, likely due to the absence of submucosal extension and/or increased proliferative activity. We recommend avoiding additional radical surgeries in patients who have endoscopically undergone complete CIAM excision unless they exhibit ominous histologic features such as submucosal extension or increased proliferative activity.

Sessile serrated adenoma/polyps (SSA/Ps) usually appear flat to sessile with a smooth-appearing surface. However, macroscopic appearances of SSA/P can vary from flat-elevated to nodular and can even show a pedunculated configuration as we previously reported. The aim of the current study was to evaluate the clinicopathologic features of another under-recognized form of SSA/P which shows a depressed surface. Among 634 cases of sessile serrated adenoma/polyp, a total of seven sessile serrated adenoma/polyps showing a depressed surface were identified in 6 patients during the review of endoscopic images between January 2013 and November 2013. One of these was found during the review of previous endoscopic images of the same patient. Patients were more often middle-aged to elderly men (83.3 %) and had synchronous conventional adenomas and/or SSA/Ps except for one man. The polyps usually occurred in the proximal colon (71.4 %) and the mean size of polyps was 9.3 mm (range; 6-13 mm). Most cases (71.4 %) were of a flat-elevated type, and the remaining polyps (28.6 %) were sessile. The majority of polyps (85.7 %) showed a mucus cap. All but one of the cases (85.7 %) showed BRAF-V600E mutations. Our findings are that SSA/Ps can show a central depression although such cases are rare. The endoscopic and clinicopathologic features of SSA/Ps showing a depressed surface appear to be similar to usual SSA/Ps except for the presence of a depressed surface and marked male preponderance. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/ 1562070886167874. [ABSTRACT FROM AUTHOR]

Background: Ectopic crypts, defined as abnormally positioned crypts that have lost their orientation toward the muscularis mucosae, have been suggested to be the best defining histologic feature of traditional serrated adenoma (TSA). However, the significance of ectopic crypt formation (ECF) in the distinction between TSA and conventional adenoma (CA) has rarely been studied. Methods: We designed this study to determine if ECF can be found in CA and its presence is exclusive to TSA. We studied 107 TSAs and 191 CAs including 106 tubular adenomas (TAs), 66 tubulovillous adenomas (TVAs), and 19 villous adenomas (VAs). Results: ECF was identified in most (79.4%) but not all TSAs. Additionally, ECF was not infrequent in CA (62 of 191, 32.5%), and its presence correlated with the presence of a villous component and larger tumor size (each p <0.001). Conclusions: Based on its strong association with the presence of a villous component and larger tumor size, ECF appears to be involved in the protuberant growth of colorectal CA. Because ECF can be found in CA, particularly in cases with a villous component, the possibility of CA should be considered before making a diagnosis of TSA when encountering colorectal polyps with ECF. [ABSTRACT FROM AUTHOR]