Pancreatic cysts are often discovered incidentally on CT or MRI. As mucinous cysts (including IPMN) have malignant potential and non-mucinous cysts do not, the initial challenge involves making this distinction. While serous cystadenomas are often microcystic and with central scar, mucinous cysts have thick epithelial walls that show isodense or hypodense enhancement on venous phase. Mucinous cystic neoplasms are most often solitary cysts located in the pancreatic body and tail and show no connection to the pancreatic duct and can have minor calcifications. On the other hand, IPMNs are found throughout the pancreas and by definition communicate with the pancreatic duct. Although MRI has a small benefit in describing these morphological features …show more content…
MD-IPMNs are more accurately diagnosed preoperatively than BD-IPMNs, however CT imaging can often identify side-branching pancreatic duct cysts seen in BD-IPMN and mixed type (Figure 3) [27]. In practice, many small pancreatic cysts are assumed to be BDIPMNs based clinical factors.
Endoscopic ultrasound (EUS) provides imaging that is complementary to CT and MRI. It is particularly useful in accurately assessing pancreatic ductal dilation (Figure 4) and in identifying high-risk stigmata for malignancy in IPMN such as internal septations, mural nodules, solid masses, vascular invasion and lymph node metastasis [28]. EUS can be also be used to sample cyst fluid or high-risk stigmata via fine-needle aspiration (FNA).
Cyst fluid contains cells shed from the epithelium and protein/
DNA/RNA biomarkers that may potentially help classify cysts as mucinous. Although imperfect, EUS with or without FNA has been found superior to CT or MRI in accurately describing neoplastic cysts [29]. Head to head trials have shown a trend towards increased sensitivity for EUS-FNA compared to CT-guided biopsy, with a much lower risk of peritoneal seeding as compared