Olga Rachel Brook MD, Presenter: Nothing to Disclose

Peter Beddy MD, FRCR, Abstract Co-Author: Nothing to Disclose

Corey Alexander Couto MD, Abstract Co-Author: Nothing to Disclose

Jay Kumar Pahade MD, Abstract Co-Author: Nothing to Disclose

Payal H. Patel MD, Abstract Co-Author: Nothing to Disclose

Ian Martin Brennan MBBCh, BMedSc, Abstract Co-Author: Nothing to Disclose

Alexander Brook PhD, Abstract Co-Author: Nothing to Disclose

Ivan Pedrosa MD, Abstract Co-Author: Research grant, Pfizer Inc Research grant, Amgen Inc Research grant, GlaxoSmithKline plc

To evaluate the growth kinetics of pancreatic cysts.

An IRB approved, HIPAA compliant retrospective review of our clinical database was conducted to find patients with pancreatic cysts that have had two or more MRI studies at least 6 months apart. All MRI examinations for the study population were reviewed to measure the largest dimension of all pancreatic cysts > 5 mm. The same plane on the axial or coronal T2-weighted single-shot fast/turbo spin echo acquisition was selected for each cyst on multiple studies for the same patient. Additional features including the presence of septations were recorded. Pancreatic cyst growth was defined as ≥2.5mm change in size. Descriptive statistics and linear regression analysis to correlate the size of the cyst at presentation with growth rate are presented.

240 patients (age 63.3 ±12.6 yrs, 101 (42%) males) with 375 pancreatic cysts greater than 5 mm were included in this study. Average cyst size at presentation was 10.4±7.2mm (range 0-63mm). Mean follow up time was 2.7±2.3yrs (range 0.5-11.1 yrs). Overall, 228 (61%) cysts were stable (mean follow up 2±1.8 yrs). Ninety-seven (26%) cysts showed an average increase in size of 6.7±5.2mm. The average growth for these 97 cysts was 3.5±2.8mm/year. The size of the cysts at presentation correlated with the growth rate. A growth rate of 1.2 mm/year was present for each 10 mm increase in cyst size (p<0.001). The presence of septations (p=0.25) and patient’s age at presentation (p=0.6) did not predict cyst growth. Delayed growth was seen in 7 (5.6%) of the 125 cysts demonstrating at least 3 years of initial stability. Fifty (13%) cysts decreased in size.

The majority of the pancreatic cysts in our study had no perceptible growth on follow up MRI. However, up to 26% of the cysts in our cohort increased in size on follow up MRI. The average growth rate for these was 3.5±2.8mm/year and was faster for larger cysts. Delayed growth after an initial period of stability occurs in approximately 6% of patients. 

Pancreatic cyst surveillance protocols should consider cyst size at presentation as larger cysts grow faster. Stability of a cyst over years is reassuring although does not exclude delayed growth.  

Brook, O, Beddy, P, Couto, C, Pahade, J, Patel, P, Brennan, I, Brook, A, Pedrosa, I, Growth Kinetics of Pancreatic Cysts.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034546.html