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.
|HP (%)||SSA (%)||P∗|
|Case||353 (80.8)||84 (19.2)|
|age (yr, mean±SD)||59.4 ±10.4||57.7±9.12||0.175|
|Sex||Female||191 (54.11)||162 (51.81)||0.715|
|Aggregated polyp size (cm, mean±SD)||0.47±0.39||0.80±0.56||< .0001|
|Site in colon||Right||46 (13.07)||41 (48.81)||< .0001|
|Transverse||30 (8.52)||29 (34.52 )|
|Left||276 (78.41)||14 (16.67)|
|Synchronous||None||285 (80.74)||61 (72.62)||0.136|
|HP||68 (19.26)||23 (27.38)|
|Synchronous||None||337 (95.47)||73( 86.90)||0.009|
|SSA||16 (4.53)||11 (13.1)|
|Synchronous||None||211 (59.77)||41 (48.81)||0.085|
|Neoplasm †||142 (40.23)||43 (51.19)|
|Synchronous||None||222 (62.89)||47 (55.95)||0.262|
|Adenoma& cancer||131 (37.11)||37 (44.05)|