Joanna G. Escalon MD, Presenter: Nothing to Disclose

Richard Kinh Gian Do MD, PhD, Abstract Co-Author: Nothing to Disclose

Matthew Porembka, Abstract Co-Author: Nothing to Disclose

Scott Gerst MD, Abstract Co-Author: Nothing to Disclose

Peter J. Allen MD, Abstract Co-Author: Nothing to Disclose

To compare the CT appearance of tubular (t) and colloid (c) type pancreatic ductal adenocarcinomas (PDAC) arising from intraductal papillary mucinous neoplasms (IPMN).

An IRB approved retrospective study included patients who underwent resection of IPMN with either invasive tPDAC or cPDAC. Consecutive patients from 1996 to 2013 were included if they had preoperative CT imaging within 90 days of surgery. Two radiologists reviewed in consensus for the presence and size of solid enhancing component (SC), main pancreatic duct (MPD) size, presence of MPD cutoff, and largest cyst diameter (D). SC size on imaging was correlated with invasive tumor size as measured by pathology. Unpaired t-test, Fisher exact test, and Spearman correlation were used for statistical analyses.

48 pts (25:23 M:F, median age 72) were included, with CT performed a median of 19 (range 1-79) days before surgery. 27 pts had cPDAC (15:12 M:F, median age 73) and 21 pts had tPDAC (10:11 M:F, median age 71). No statistically significant difference was found between tPDAC and cPDAC for D (median 33 vs 23 mm, p = 0.25) or MPD size (median 10 vs 6 mm, p = 0.46). A SC was visible in 14 of 27 cPDAC and 16 of 21 tPDAC (p = 0.13). MPD cutoff was seen in 4 of 27 cPDAC and 8 of 21 tPDAC (p = 0.21). For the pathologic specimen, the median size of the invasive tumor for cPDAC was 24 mm and for tPDAC was 19 mm (p=0.36). The correlation between SC size measured on CT and pathologic tumor size was R2=0.50 (p<0.0001) for cPDAC, and R2=0.08 for tPDAC (p=0.20).

No significant difference was seen between the CT appearances of IPMN with either colloid or tubular PDAC. However, in contrast to tPDAC, the size of solid enhancing component for cPDAC measured on CT was associated with invasive tumor size on pathology. The abundant extracellular mucin present in cPDAC may explain the correlation between SC size measured on CT and pathology.

Given the differences in prognosis between IPMN with either colloid and tubular pancreatic ductal adenocarcinomas, improved understanding of their CT appearance may prove useful.

Escalon, J, Do, R, Porembka, M, Gerst, S, Allen, P, Comparison of CT Appearance of Tubular and Colloid Pancreatic Adenocarcinoma Arising from Intraductal Papillary Mucinous Neoplasm.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007494.html