Serrated Lesions of the Appendix A Morphologic and Immunohistochemical Appraisal
ABSTRACT We performed a histologic and immunohistochemical assessment of 53 noninvasive appendiceal epithelial proliferations, appropriating terminology and using markers shown useful in differentiating serrated colorectal polyps. These were classified as hyperplastic polyp (HP), sessile serrated adenoma (SSA), mixed serrated and adenomatous lesion (MSAL), mucinous cystadenoma (MCA), or conventional adenoma (CAD). Immunohistochemical analysis for cytokeratin (CK) 20, Ki-67, MUC6, and beta-catenin was performed. Diagnoses were as follows: HP, 6; SSA, 12; HP vs SSA, 3; MSAL, 16; MCA, 14; and CAD, 2. All HPs showed expanded (beyond surface) CK20 and expanded or normal (base) Ki-67; 1 was MUC6+. Most SSAs and MSALs were CK20-expanded or expanded with random expression in deep crypts (Ex/I) and Ki-67-expanded, Ex/I (expanded with asymmetry), or normal. All SSAs and 8 of 16 MSALs were MUC6+. CADs were CK20-Ex/I, Ki-67-Ex, and MUC6-; 1 showed nuclear beta-catenin expression. Serrated appendiceal lesions can be categorized using colorectal terminology. MUC6 is associated with SSA morphologic features. Similar immunohistochemical patterns in SSA and MSAL suggest a link between these lesions.
SourceAvailable from: Chouhei Sakakura[Show abstract] [Hide abstract]
ABSTRACT: Although the definition of sessile serrated lesion (SSL) of colon is controversial and the risk of progression to malignancy is also under investigation at present, SSL is generally described as a polyp characterized by a serrated architecture. It is estimated to represent a feature of a new cancerization pathway, coined "serrated neoplasia pathway," particularly in right-sided colon adenocarcinomas. On the other hand, in appendix, the role of this pathway remains uncertain, probably because very few cases of appendiceal adenocarcinoma associated with SSL were reported, and furthermore, immunohistochemical examination was rarely carried out. We herein report an interesting case of invasive appendiceal mucinous adenocarcinoma exhibiting SSL, which was pathologically estimated as a potential precursor lesion, and performed representative immunohistochemistry for both the mucinous adenocarcinoma and SSL in the same specimen. To further elucidate the progression of the appendiceal carcinoma from SSL, both an adequate sectioning of the lesion and systematic immunohistochemical examination of a large number of appendiceal carcinoma cases containing adjacent SSL would be required.07/2014; 2014:979674. DOI:10.1155/2014/979674
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ABSTRACT: Background/Aims: The aim of this study is, therefore, to classify appendiceal serrated polyps in a large case series with respect to the recent World Health Organization classification using diagnostic criteria provided for colorectal serrated polyps. Materials and Methods: A total of 960 appendix specimens diagnosed between 2005 and 2010 were reviewed retrospectively, and cases presenting with a polyp with serrated morphology were classified with reference to the recent World Health Organization criteria. Histologic criteria comprised architectural features of the crypts, including serration, branching, basal dilatation, inverted T-or L-shaped crypts together with cytologic features comprising a mucin pattern, dysplasia, in terms of pseudostratification and nuclear atypia, mitoses in the upper crypts, and cytoplasmic eosinophilia. Results: A total of 71 cases (7.39%) were diagnosed as serrated polyps, including 36 (50.7%) hyperplastic polyps, 33 (46.48%) sessile serrated adenoma/polyps, and 2 (2.81%) traditional serrated adenomas. There were 32 males and 39 females with an age range of 2 to 82 years. Histology revealed that the majority of both hyperplastic polyps (63.9%) and sessile serrated adenomas/polyps (74.3%) involved the entire appendiceal circumference. Basal dilatation (94.3%), basal serration (94.3%), T-/L-shaped crypts (94.3%), and ectopic crypts (68.6%) were significantly more commonly observed in sessile serrated adenomas/polyps compared to hyperplastic polyps. Dysplasia was observed in 31.4% of sessile serrated adenomas/polyps, while hyperplastic polyps did not show dysplasia. Conclusion: The results of the present study suggest that appendiceal serrated polyps, despite bearing many similarities with their colorectal counterparts, may have some special features due to the anatomic uniqueness of the organ itself and also the polyps arising from its mucosal lining.The Turkish journal of gastroenterology: the official journal of Turkish Society of Gastroenterology 02/2014; 25(1):29-34. DOI:10.5152/tjg.2014.4056 · 0.47 Impact Factor
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ABSTRACT: Context .- Immunohistochemistry has assumed an increasing role in the identification and characterization of gynecologic disorders including lesions with deceptively bland morphology, uncommon and underdiagnosed neoplasms, and neoplasms with specific genetic alterations associated with overexpression or loss of expression of specific proteins. The diagnostic accuracy has been significantly improved owing to the discovery and increasing experience with the tumor-associated biomarkers, and the increasing demand for precise tumor classification to assess suitability for the expanding therapeutic modalities including clinical trials. Objective .- To differentiate lesions of the gynecologic tract through the use of effective immunohistochemical panels. Data Sources .- Literature review and authors' personal practice experience. Conclusions .- The application of diagnostic and prognostic immunohistochemical panels has enabled pathologists to better guide therapeutic decisions and to better predict the clinical outcome. It is now well established that the use of ancillary testing, including immunohistochemistry, has a significant power in the identification, differentiation, and classification of reactive, premalignant, and malignant gynecologic disorders. This article discusses the utilities and pitfalls of the commonly used immunohistochemical markers in the context of overlapping morphologic features encountered in the uterus, ovaries, and fallopian tubes.Archives of pathology & laboratory medicine 01/2015; 139(1):39-54. DOI:10.5858/arpa.2014-0057-RA · 2.88 Impact Factor