Go Eun Kim, Presenter: Nothing to Disclose

Sang Soo Shin MD, Abstract Co-Author: Nothing to Disclose

Jin Woong Kim MD, Abstract Co-Author: Nothing to Disclose

Suk Hee Heo MD, Abstract Co-Author: Nothing to Disclose

Hyo Soon Lim MD, Abstract Co-Author: Nothing to Disclose

Yong-Yeon Jeong MD, Abstract Co-Author: Nothing to Disclose

Heoung-Keun Kang MD, Abstract Co-Author: Nothing to Disclose

To restrospectively determine natural history of incidentally detected focal cystic pancreatic lesions (CPLs) less than 3cm with an average imaging follow-up (F/U) of 34 months.

Throughout a 60-month period, a cohort of patients with incidental CPLs were identified using a computerized search. Patients, who fulfilled all of following criteria, were enrolled in this study; 1) available CT or MR images with F/U interval more than 6 months, 2) CPLs that were unilocular, 3) CPLs less than 3cm in size, 4) CPLs that were not given any specific diagnosis on initial CT or MR images, 5) no symptoms referable to pancreas, 6) no history of pancreatitis. CT and MR images were analyzed regarding location and size of CPLs. According to interval size change, CPLs were divided into three groups (increase, no change, decrease).

Among 1514 patients with incidental CPLs, 565 patients were confirmed to meet inclusion criteria. While 495 pateints had one CPL, 70 patients had more than two CPLs. The mean size of 661 CPLs in 565 patients was 11.7 mm on initial CT or MR images. Regarding location, 661 CPLs were located in head (n=241), neck (n=52), body (n=200) and tail (n=168). During F/U, 14 CPLs were confirmed as benign (n=11) and malignant (n=3). Fourteen CPLs with pathological diagnosis were classified into interval increase (n=5), no change (n=5), and interval decrease (n=4) group, respectively. Per-lesion-based analysis showed that 661 CPLs increased in 23% (152 CPLs), did not change in 69.9% (462 CPLs) and decreased in 7.1% (47 CPLs) during F/U. The mean size of 152 CPLs that showed interval increase was 12.1 mm and 19.8 mm on initial and final F/U images, respectively, among which 85.5% (130 CPLs) were still less than 3cm on final F/U images. While two (1.5%) of enlarged 130 CPLs less than 3cm were pathologically confirmed as benign (n=2), three (13.6%) of enlarged 22 CPLs greater than 3cm were confirmed as malignant (n=3).

Our data suggest that 152 CPLs (23%) of incidental CPLs of 3cm or smaller showed interval increase during a mean F/U of 34.2 months, among which 130 CPLs (85.5%) were still negative for malignancy in the last F/U imaging.

Although incidental cystic pancreatic lesions of 3cm or smaller could increase in size, most of asymptomatic CPLs can be observed safely, at least for a mean period of 3 years.

Kim, G, Shin, S, Kim, J, Heo, S, Lim, H, Jeong, Y, Kang, H, The Natural History of Incidental Cystic Pancreatic Lesions Less than 3cm: Results of Mid-term Follow-up and Clinical Significance.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045630.html