Pancreas cystic lesion with surprise findings on confocal laser endomicroscopy.

Background and Aims: The incidental diagnosis of pancreatic cystic lesions has been increasing, ranging from 2% to 45%, as determined by computed tomography or magnetic resonance imaging. This report describes the case of a 74-year-old female patient referred for a finding on magnetic resonance imaging of a unilocular cystic lesion in the pancreas tail. Methods: Based on the cyst's size and its unclear nature, the patient was subjected to a repeat EUS at our institution, which showed an anechoic 35 × 20-mm finely septated lesion in the pancreatic tail. To help determine the nature of the cyst, EUS-guided needle-based confocal laser endomicroscopy (EUS-nCLE) was used because of its ability to visualize the cyst wall mucosal layer to a micrometer resolution. Results: EUS-nCLE of the cyst wall showed an intersecting network of vessels, with background arrangement of gray oval structures and at times background arrangement of dark lobular structures. The findings were not consistent with a mucinous pancreas cyst, serous cystadenoma, or cystic neuroendocrine tumor. As for the NGS, the cyst fluid was positive for both Conclusion: Lymphangiomas of the pancreas are rare, accounting for 0.2% of all pancreatic lesions. Targeted NGS performed at our institution on the surgical specimen showed absence of