Editorial
Recognizing sessile serrated adenomas/polyps: a diagnostic challenge for pathologists
Author
Runjan Chetty
Institution
Department of Pathology, Toronto General Hospital, Toronto, Ontario, Canada
Bibliography DOI http://dx.doi.org/ 10.1055/s-0033-1344861 Endoscopy 2013; 45: 906–906 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0013-726X
In the past 15 years, it has become increasingly clear that a significant proportion of colorectal cancers arise from a serrated precursor lesion rather than the conventional adenoma. These lesions are known as sessile serrated adenoma or polyps (SSA/P) and are mediated by a different molecular (serrated) pathway to the chromosomal instability pathway. Several researchers have suggested that the serrated pathway is an accelerated one leading to carcinogenesis. For these reasons, it is imperative that both gastroenterologists and pathologists are not only aware of the existence of SSA/P, but are able to make the correct diagnosis and, subsequently, to manage the patient appropriately. It must be acknowledged that pathologists have been slow to recognize SSA/P and this is largely due to lack of awareness. For those who are aware of the lesion, some confusion has prevailed about the diagnostic criteria and the association with dysplasia. Recently, the American College of Gastroenterology established diagnostic criteria for the diagnosis of SSA/P [1]. Despite this and other previous publications highlighting histologic criteria, there remains poor recognition of the entity [2, 3]. Over and above awareness (which is increasing), there are technical factors that often impede a pathologist’s ability to provide a confident diagnosis of SSA/P. As highlighted in the paper by Morales et al. in this issue of Endoscopy, orientation of the tissue section is an important rate-limiting step in making the diagnosis of SSA/P and distinguishing it from a hyperplastic polyp [4]. Due to obliquity of sectioning, the architectural features that are critical for the diagnosis of SSA/P are not readily apparent despite serial or stepwise sec-
Corresponding author Runjan Chetty, MBBCh, FRCPath, FRCPC, DPhil Department of Pathology 11th floor, Eaton Wing Toronto General Hospital 200 Elizabeth St. Ontario M5G 2C4 Canada Fax: 1-416-340-5517 [email protected]
Chetty RunjanRunjan . Recognizing sessile serrated adenomas and polyps … Endoscopy 2013; 45: 906
tions through the tissue. The pathologist is then left with the unsatisfactory diagnosis of an “indeterminate or unclassifiable serrated” lesion, that may be an SSA/P or a hyperplastic polyp. The study by Morales et al. advocates and recommends an easy and inexpensive way to ensure that proper orientation can be achieved in a larger proportion of cases. They have assessed a significant number of SSA/P specimens using an orientation score and also showed an almost 35 % increased diagnosis rate of SSA/Ps using their modified “envelope” technique compared with routine practice [4]. Improved orientation will eliminate some of the equivocal or indeterminate diagnoses of SSA/P, thus ensuring a more accurate diagnosis on which the clinician can act to determine surveillance protocols. Competing interests: None
References 1 Rex DK, Ahnen DJ, Baron JA et al. Serrated lesions of the colorectum: review and recommendations from an expert panel. Am J Gastroenterol 2012; 107: 1315 – 1329 2 Gill P, Wang LM, Bailey A et al. Reporting trends of right-sided hyperplastic and sessile serrated polyps in a large teaching hospital over a 4-year period (2009–2012). J Clin Pathol 2013; 66: 655 – 658 3 Leedham S, East JE, Chetty R. Diagnosis of sessile serrated polyps/adenomas: what does this mean for the pathologist, gastroenterologist and patient? J Clin Pathol 2013; 66: 265 – 268 4 Morales S, Bodian C, Kornacki S et al. A simple tissue handling technique performed in the endoscopy suite improves histologic section quality and diagnostic accuracy for serrated polyps. Endoscopy 2013; 45: 897 – 905
This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.
906
Copyright of Endoscopy is the property of Georg Thieme Verlag Stuttgart and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Recognizing sessile serrated adenomas/polyps: a diagnostic challenge for pathologists
Author
Runjan Chetty
Institution
Department of Pathology, Toronto General Hospital, Toronto, Ontario, Canada
Bibliography DOI http://dx.doi.org/ 10.1055/s-0033-1344861 Endoscopy 2013; 45: 906–906 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0013-726X
In the past 15 years, it has become increasingly clear that a significant proportion of colorectal cancers arise from a serrated precursor lesion rather than the conventional adenoma. These lesions are known as sessile serrated adenoma or polyps (SSA/P) and are mediated by a different molecular (serrated) pathway to the chromosomal instability pathway. Several researchers have suggested that the serrated pathway is an accelerated one leading to carcinogenesis. For these reasons, it is imperative that both gastroenterologists and pathologists are not only aware of the existence of SSA/P, but are able to make the correct diagnosis and, subsequently, to manage the patient appropriately. It must be acknowledged that pathologists have been slow to recognize SSA/P and this is largely due to lack of awareness. For those who are aware of the lesion, some confusion has prevailed about the diagnostic criteria and the association with dysplasia. Recently, the American College of Gastroenterology established diagnostic criteria for the diagnosis of SSA/P [1]. Despite this and other previous publications highlighting histologic criteria, there remains poor recognition of the entity [2, 3]. Over and above awareness (which is increasing), there are technical factors that often impede a pathologist’s ability to provide a confident diagnosis of SSA/P. As highlighted in the paper by Morales et al. in this issue of Endoscopy, orientation of the tissue section is an important rate-limiting step in making the diagnosis of SSA/P and distinguishing it from a hyperplastic polyp [4]. Due to obliquity of sectioning, the architectural features that are critical for the diagnosis of SSA/P are not readily apparent despite serial or stepwise sec-
Corresponding author Runjan Chetty, MBBCh, FRCPath, FRCPC, DPhil Department of Pathology 11th floor, Eaton Wing Toronto General Hospital 200 Elizabeth St. Ontario M5G 2C4 Canada Fax: 1-416-340-5517 [email protected]
Chetty RunjanRunjan . Recognizing sessile serrated adenomas and polyps … Endoscopy 2013; 45: 906
tions through the tissue. The pathologist is then left with the unsatisfactory diagnosis of an “indeterminate or unclassifiable serrated” lesion, that may be an SSA/P or a hyperplastic polyp. The study by Morales et al. advocates and recommends an easy and inexpensive way to ensure that proper orientation can be achieved in a larger proportion of cases. They have assessed a significant number of SSA/P specimens using an orientation score and also showed an almost 35 % increased diagnosis rate of SSA/Ps using their modified “envelope” technique compared with routine practice [4]. Improved orientation will eliminate some of the equivocal or indeterminate diagnoses of SSA/P, thus ensuring a more accurate diagnosis on which the clinician can act to determine surveillance protocols. Competing interests: None
References 1 Rex DK, Ahnen DJ, Baron JA et al. Serrated lesions of the colorectum: review and recommendations from an expert panel. Am J Gastroenterol 2012; 107: 1315 – 1329 2 Gill P, Wang LM, Bailey A et al. Reporting trends of right-sided hyperplastic and sessile serrated polyps in a large teaching hospital over a 4-year period (2009–2012). J Clin Pathol 2013; 66: 655 – 658 3 Leedham S, East JE, Chetty R. Diagnosis of sessile serrated polyps/adenomas: what does this mean for the pathologist, gastroenterologist and patient? J Clin Pathol 2013; 66: 265 – 268 4 Morales S, Bodian C, Kornacki S et al. A simple tissue handling technique performed in the endoscopy suite improves histologic section quality and diagnostic accuracy for serrated polyps. Endoscopy 2013; 45: 897 – 905
This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.
906
Copyright of Endoscopy is the property of Georg Thieme Verlag Stuttgart and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
