Post written by Samer El-Dika, MD, FASGE, from Stanford University, Stanford, California, USA.

This video case involves a 74-year-old woman with a pancreatic tail cyst identified incidentally. Initial imaging and fluid analysis suggested a nonmucinous cyst, but amylase levels hinted at possible duct communication.

To better characterize the lesion, we used EUS-guided needle-based confocal laser endomicroscopy (EUS-nCLE). The findings were inconsistent with typical neoplastic cysts. Next-generation sequencing classified the cyst as the high-risk category of mucinous cysts. Surgical pathology later confirmed a benign vascular malformation (lymphangioma), a very rare finding in the pancreas.

This case was important to share because it highlights how EUS-nCLE can reveal nonepithelial cyst features, prompting re-evaluation of surgical decisions. Despite false-positive molecular results (KRAS and PIK3CA mutations), EUS-nCLE suggested a non-neoplastic lesion. It underscores the value of integrating EUS-nCLE findings, especially after nondiagnostic conventional evaluation of pancreatic cysts.

Other endoscopists can gain from the experience:    

• Endoscopists performing EUS-nCLE need to familiarize themselves with the epithelial and vascular patterns of neoplastic pancreatic cysts while being able to recognize non-neoplastic features, such as intersecting blood vessels, adipocytes, or pancreatic acini.
• False-positive next-generation sequencing results can occur.
• When no epithelial pattern is found and EUS-nCLE consistently shows non-neoplastic pancreatic cyst features, close follow-up should be considered, particularly when major surgery is required to achieve resection.

EUS-guided needle-based confocal laser endomicroscopy image of the cyst wall depicting the intersecting network of vessels.

Read the full article online.

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