Features associated with progression of small pancreatic cystic lesions: A retrospective study.

Aim: To investigate the progression rate of small pancreatic cystic lesions and identify characteristics associated with their progression.

Methods: Patients with pancreatic cystic lesions with at least 1-year of follow-up were evaluated retrospectively. We excluded patients with cysts larger than 3 cm or with features that were a concern for malignancy. In total, 135 patients were evaluated. The interval progression of the cysts was examined. Characteristics were compared between patients with and without progression.

Results: The pancreatic cysts ranged from 3 to 29 mm. The mean follow-up period was 4.5 ± 2.3 years and the mean progression rate was 1.0 ± 1.3 mm/year. Ninety patients showed interval progression and were divided into two groups; the minimal-change group (n = 41), who had cyst progression at less than 1 mm/year, and the progression group (n = 49), who had a progression rate of more than 1 mm/year. Compared with the cysts without progression, the lesions of the progression group were more frequently associated with tubular cyst, septation or a prominent pancreatic duct (P < 0.05). The odds ratio for progression was 5.318 for septation and 4.582 for tubular cysts.

Conclusion: Small pancreatic cysts progress slowly. Lesions with tubular shape, septa, or prominent pancreatic duct were more likely to progress, and required further diagnostic intervention or shorter surveillance interval.