[611] Clinicopathological Characterization of 437 Hyperplastic and Sessile Serrated Polyps

Zheng Chen, Elliot A Krauss, Lanjing Zhang. Merck& Co., Rahway, NJ; University Medical Center of Princeton, Plainsboro, NJ; Robert Wood Johnson Medical School, New Brunswick, NJ

Background: Sessile serrated adenoma/polyp (SSA) is a relatively new concept and major differential diagnosis of serrated polyps. Its clinical and pathologic features are not fully understood.
Design: We included the consecutive hyperplasic polyp (HP) and SSA specimens collected at our institution from Aug. 2011 to Aug. 2012. With IRB approval, the following data were collected and analyzed: age, sex, polyp site, aggregated polyp size on H&E slide (APS), and synchronous neoplasm (SN) including adenoma, SSA and cancer. Statistical analyses were conducted by using Stata (ver. 12).
Results: A total of 437 specimens were chosen including 353 HP and 84 SSA. The APS of SSA was larger than HP (0.80±0.56 cm vs. 0.47±0.39 cm, P< .0001). Compared with HP, SSA was more likely associated with proximal colon (P< .0001) and synchronous SSA (P= .0009), but not synchronous HP or synchronous cancer. Multivariate regression analysis (MRA) showed that SSA was more likely diagnosed in the polyps in proximal colon (Odds ratio [OR] 3.6, P< .0001), of larger APS (OR 4.0, P< .0001) and with synchronous SSA (OR 3.0, P= .027). MRA also showed SN was more likely found in patients of male gender (OR 1.94, P= .001), of older age (OR 1.02, P= .039), and with the index polyp in proximal colon (OR 1.27, P= .047), but not related to polyp type (SSA vs. HP) or APS.
Conclusions: SSA and HP have equal likelihood of a SN, while male gender, older age and location of the index serrated polyp (HP or SSA) in the proximal colon are more likely associated with a SN. There is no correlation between the size of the index serrated polyp (HP or SSA) and the presence of a SN. To diagnose SSA, larger APS, synchronous SSA, and location in proximal colon may be useful.

Table 1 Characteristics of HP and SSA
 HP (%)SSA (%)P∗
Case353 (80.8)84 (19.2) 
age (yr, mean±SD)59.4 ±10.457.7±9.120.175
SexFemale191 (54.11)162 (51.81)0.715
 Male162(45.89)40 (48.19) 
Aggregated polyp size (cm, mean±SD)0.47±0.390.80±0.56< .0001
Site in colonRight46 (13.07)41 (48.81)< .0001
 Transverse30 (8.52)29 (34.52 ) 
 Left276 (78.41)14 (16.67) 
SynchronousNone285 (80.74)61 (72.62)0.136
 HP68 (19.26)23 (27.38) 
SynchronousNone337 (95.47)73( 86.90)0.009
 SSA16 (4.53)11 (13.1) 
SynchronousNone211 (59.77)41 (48.81)0.085
 Neoplasm †142 (40.23)43 (51.19) 
SynchronousNone222 (62.89)47 (55.95)0.262
 Adenoma& cancer131 (37.11)37 (44.05) 
HP: Hyperplastic polyp; SSA: Sessile serrated adenoma/polyp; ∗Fisher exact or ANOVA test; †Includes adenoma, SSA& cancer.

Category: Gastrointestinal

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 128, Tuesday Afternoon


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