Cases and Techniques Library (CTL) E7 Sessile serrated lesion misdiagnosed as a hyperplastic polyp Fig. 2 Biopsy of the lesion found 5 years previously, which was initially interpreted as being a hyperplastic polyp, although on later review features of a ser- rated polyp were identi- fied. Fig. 1 Endoscopic appearance of a prominent fold identified in the proximal ascending colon during a colonoscopy performed 5 years prior to presentation. Fig. 4 Endoscopic appearance during a colonoscopy performed for investigation of ane- mia showing an invasive colon cancer in the area where the “hyperplas- tic” polyp had initially been seen 5 years pre- viously. Fig. 3 Endoscopic appearance of the polyp in the proximal ascending colon during a colo- noscopy performed 1 year later, showing no significant change. An 81-year-old woman presented for trally depressed lesion that was suspi- sions are now recognized as an important colonoscopy because of iron deficiency cious of malignancy in the same location neoplastic precursor to adenocarcinoma anemia. She had undergone colonoscopy within the proximal ascending colon of the colon [2,3]. After reinterpretation, 5 years previously during which a 2-cm (●" Fig.4). Endoscopic biopsies of this many lesions identified as hyperplastic in prominent fold had been identified in the lesion were consistent with invasive ade- the past can be reclassified as serrated le- proximal ascending colon (●" Fig.1). A nocarcinoma. She underwent laparos- sions [4]. In the illustrated case, the initial This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. biopsy of this lesion was interpreted as copy-assisted right hemicolectomy and biopsies had features suggestive of a ser- being a hyperplastic polyp (●" Fig. 2), al- partial hepatectomy of two metastatic rated polyp but were misinterpreted as though the polyp showed features of a lesions; a third lesion was ablated by hyperplastic because of the reduced recog- serrated lesion. Because of clinical con- interventional radiology. Final pathology nition of these lesions at that time and the cern over a more sinister process, colo- revealed a 6.9-cm mass with two meta- limitations of interpreting polyp patholo- noscopy was repeated 1 year later. The static liver lesions, stage T3N0M1a. Re- gy from small forceps biopsies. As endo- endoscopic appearance of the area of con- view of the initial biopsies confirmed scopic mucosal resection of large polyps is cern was unchanged (●" Fig.3); biopsies that the proximal ascending colon polyp a safe and efficacious technique, polyps were again interpreted as being consis- seen initially 5 years previously was a ses- should be resected to ensure accurate tent with a hyperplastic polyp. Endo- sile serrated lesion. pathology. The illustrated case is unique scopic resection was not performed. Although in the past many serrated lesions as it demonstrates the unfortunate natural At the time of re-presentation, she was were misdiagnosed as benign hyperplastic history of an unresected serrated adeno- found to have a hemoglobin of 6.1g/dL. polyps, increasing pathologist and endos- ma, developing into a metastatic adeno- Colonoscopy was repeated and she was copist recognition has reduced the rate of carcinoma over a 4-year time period. Fur- found to have a 5-cm nongranular, cen- occurrence of this error [1]. Serrated le- thermore, the case highlights the limita- Keswani Rajesh N et al. Sessile serrated lesion misdiagnosed as hyperplastic polyp … Endoscopy 2014; 46: E7–E8 E8 Cases and Techniques Library (CTL) tions of optical and histologic diagnosis of References Bibliography serrated polyps and the critical impor- 1 Singh H, Bay D, Ip S et al. Pathological reas- DOI http://dx.doi.org/ tance of resecting these lesions because of sessment of hyperplastic colon polyps in a 10.1055/s-0033-1358928 city-wide pathology practice: implications Endoscopy 2014; 46: E7–E8 their malignant potential. for polyp surveillance recommendations. © Georg Thieme Verlag KG Gastrointest Endosc 2012; 76: 1003–1008 Stuttgart · New York Endoscopy_UCTN_Code_CPL_1AJ_2AB 2 Bouwens MW, Riedl RG, Bosman FT et al. ISSN 0013-726X Large proximal serrated polyps: natural his- Competing interests: None tory and colorectal cancer risk in a retro- spective series. J Clin Gastroenterol 2013; Corresponding author 47: 734–735 Rajesh N. Keswani, MD 3 Sweetser S, Smyrk TC, Sinicrope FA. Serrated 676 N. St. Clair, Suite 1400 1 1 Rajesh N. Keswani , A. Aziz Aadam , colon polyps as precursors to colorectal can- Chicago Guang-Yu Yang2 cer. Clin Gastroenterol Hepatol 2013; 11: Illinois 60611 760–767 1 USA Division of Gastroenterology, 4 Khalid O, Radaideh S, Cummings OW et al. Fax: +1-312-695-6999 Department of Medicine, Northwestern Reinterpretation of histology of proximal [email protected] University Feinberg School of Medicine, colon polyps called hyperplastic in 2001. – Chicago, Illinois, USA World J Gastroenterol 2009; 15: 3767 3770 2 Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Keswani Rajesh N et al. Sessile serrated lesion misdiagnosed as hyperplastic polyp … Endoscopy 2014; 46: E7–E8.