Comparison of pathology sampling protocols for pancreatoduodenectomy specimens

Pancreatoduodenectomy is one of the most challenging surgical specimens for pathologists. Recently, two different, standardized protocols have been proposed: the axial slicing Leeds protocol (LP) and the bi-valving Adsay protocol (AP). Comparison between standardized and non-standardized protocols (NSP) was performed with emphasis on margin involvement and lymph node yield. Pancreatoduodenectomy cases were retrospectively recruited: 46 sampled with LP, 52 cases with AP and 46 cases with NSP. Clinico-pathologic data and rates of margin/surface involvement were collected and their prognostic influence on survival was assessed. Statistical differences between NSP and AP and LP were seen for nodal yield (p = 0.0001), N+ (p = 0.0001) and lymph node ratio - LNR (p < 0.0008) but not between AP and LP. Differences in R1/R0 status were statistically significant between NSP group (R1-15%) and both the LP (R1-73.9%) and AP (R1-70%) groups (p = 0.0001) but not between LP and AP groups. At univariate survival analysis, grade (p = 0.0023) and number of involved margins (p = 0.0096) in AP and "N-category" (p = 0.0057) "resection margin status" (p = 0.0094), "stage" (p = 0.0143), and "number of involved margins" (p = 0.00398) in LP were statistically significant, while no variable was significant in the NSP group. At multivariate analysis "N category," "resection margin status," "stage," "number of involved margins," and "LNR" retained significance for the LP group. These results show that both LP and AP perform better than non-standardized sampling making standardization mandatory in pancreatoduodenectomy cut up. Both AP and LP show strengths and weaknesses, and these may impact on the choice of protocol in different institutions.