Advances in imaging technology have improved the annual detection rate of pancreatic cystic lesions (PCLs), but the preoperative diagnosis of PCLs remains unclear. Thus, the usefulness of single-operator cholangioscopy (SOC) as a diagnostic imaging tool for PCLs is worth investigating. We performed an intracystic visual examination of PCLs using SOC to determine the diagnostic value of SOC for PCLs.

In this retrospective observational study, PCLs were confirmed using a diagnostic imaging modality. Patients who underwent an EUS-guided through-the-needle fiberoptic pancreatic cystoscopy and SOC examination and those whose lesion type was definitively diagnosed were included (n = 43). If the cystic fluid was turbid, a physiologic saline solution was injected into the cyst, and a SOC fiberoptic probe was inserted through a 19-gauge needle to observe the wall of the intracystic cavity and its contents. The characteristics were recorded, and the cystic fluid and biopsy specimens were further assessed by performing liquid-based cytologic and histopathologic examinations. Particularly, histopathologic examinations were performed in patients who underwent surgery.

Intracystic characteristics of the confirmed cases of PCLs (43 patients) were identified through intracystic visual examination with SOC. The clarity of cyst fluid is a prerequisite for imaging by SOC. The tree-like branching pattern of blood vessel distribution may be a serous cystic neoplasm–specific characteristic. Intracystic papilla-like structure is an important characteristic for diagnosing mucinous cystic neoplasms.

The identified imaging characteristics such as blood vessel distribution on the intracystic wall and the contents of different PCLs observed under the SOC probe can provide useful information for diagnosing PCLs. SOC could be an important ancillary imaging test of PCLs by EUS.