Helping doctors manage certain pancreatic lesions more effectively

Branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) are complicated to treat. They are located in the pancreas, but their position in the branch ducts makes them difficult to access. So the benefit of accessing these branches for resection of (removing by cutting) the lesion or lesions must be weighed against the risks. IPMNs in the branch ducts are thought to be less likely to progress to cancer than those in the main duct of the pancreas.

According to the study, "Management of branch-duct intraductal papillary mucinous neoplasms: a large single-center study to assess predictors of malignancy and long-term outcomes," endoscopic ultrasound with fine needle aspiration (EUS-FNA) increasingly has been used to determine characteristics of these neoplasms. But the benefit of doing so has not been well described.

EUS is a technique using sound waves known as ultrasound during an endoscopic procedure to look at or through the wall of the gastrointestinal tract. Under continuous, real-time ultrasound guidance, a thin needle can be advanced into these structures to draw out (aspirate) fluid from the tissue. The cells obtained from the FNA can be analyzed under a microscope for abnormalities such as cancer.

In order to choose the most beneficial approach, doctors may rely not only on the size, but also on specific features, of the lesions in order to choose the best treatment approach. The study authors sought to determine the overall impact of this procedure on the identifying worrisome lesions and referring patients for surgery, compared with imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI).

This retrospective study looked at patients with established BD-IPMNs, evaluated in a tertiary care referral center between 2001 and 2013. The researchers looked for associations between worrisome features (such as signs of bleeding or nodules) and malignancy in the lesions, as well as effectiveness of endoscopic ultrasound-fine needle aspiration (EUS-FNA) for diagnosing malignant BD-IPMNs. The study also looked at recurrence of lesions and long-term outcomes of BD-IPMN patients who underwent a surgical resection.

Of 364 patients with BD-IPMN, 229 underwent imaging surveillance and 135 went on to have surgery to remove the lesion (resection). The study focused on these 135 patients. With CT/MRI, worrisome findings were similar between the benign and malignant groups, but main pancreatic duct (MPD) dilation (5-9 mm) was more frequently identified in malignant lesions.

On EUS-FNA, suspicious features of the lesions were more frequently detected in the malignant group compared with CT/MRI. Mural (in the wall) nodules, specifically, identified by EUS were missed by CT/MRI in 28% of the malignant group.

Patients with malignant lesions had a higher risk of any IPMN recurrence during a mean follow-up period of 10.9 years. Benign IPMN recurrence was observed in some patients up to eight years after resection.

The authors concluded that there is incremental value of EUS-FNA over imaging in identifying malignant BD-IPMNs, and the procedure is particularly beneficial for patients who have lesions without obvious worrisome features and those with smaller cysts.