Endoscopy 2019; 51(04): S92
DOI: 10.1055/s-0039-1681440
ESGE Days 2019 oral presentations
Saturday, April 6, 2019 08:30 – 10:30: Colonic polyps: characterization Club D
Georg Thieme Verlag KG Stuttgart · New York

TRADITIONAL SERRATED ADENOMA – SIGNS OF SERRATED AND NONSERRATED TYPES OF COLON POLYPS

N Ageykina
1   Medsi Clinic, Moscow, Russian Federation
,
N Oleynikova
2   Lomonosov Moscow State University, Moscow, Russian Federation
,
P Malkov
2   Lomonosov Moscow State University, Moscow, Russian Federation
,
E Fedorov
2   Lomonosov Moscow State University, Moscow, Russian Federation
3   Pirogov Russian National Research Medical University, Moscow, Russian Federation
,
N Danilova
2   Lomonosov Moscow State University, Moscow, Russian Federation
,
O Kharlova
2   Lomonosov Moscow State University, Moscow, Russian Federation
› Author Affiliations
Further Information

Publication History

Publication Date:
18 March 2019 (online)

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Aims:

To study the endoscopic and pathological features of traditional serrated adenoma (TSAs) of the colon.

Methods:

14 TSA (2.8%) with different grade dysplasia and a single adenocarcinoma focus were identified among 500 polyps of 265 patient's colonoscopies. The key endoscopic and pathological features of the TSAs and IHC studies with CD44, Ki67, Msi-1 and 1-and 3 – claudins antibodies were evaluated.

Results:

Most of polyps were located in the left colon (9; 64.3%), endoscopic were red (13; 92.9%), had size 0.5 – 4.5 cm. Macroscopically, 35.7% polyps were flat-elevated 0-IIa, 64.3% polyps had protruding type 0-Is, 0-Isp, 0-Ip. 21.4% cases with pit pattern type II, difficult to differentiate from hyperplastic polyps (HP) and sessile serrated adenomas (SSA); 78.6% – pattern type IV, more typical for adenoma tubular-villous (ATV) and adenoma villous (AV). Immunohistochemically TSA is close to AT/ATV in its properties and fundamentally different from HP/SSA, despite the fact that in current classification they belong to the group of serrated polyps. Statistically significant differences:

  • a similar distribution of CD44 (surface) of the AT, ATV, and TSA;

  • similar levels of Msi-1 cytoplasmic response in AT, ATV and TSA;

  • similar levels of Claudine-1 and -3 expression in ATV and TSA.

Conclusions:

Presently exact endoscopic and morphological criteria of TSA are not indicated. Often TSA corresponds to protruding type polyps, red in color, with microscopic pit pattern type IV. The presence of characteristic ectopic crypts is almost impossible to distinguish from the branching of crypts in any ATV or AV, and there is no consensus on the number of ectopic crypts required for TSA verification. Given the low incidence of TSA, the similarity of endoscopic features and the absence of immunohistochemical differences between TSA and AT/ATV, the feasibility of TSA allocation in a separate classification group is debated and requires further study.