Mucinous cystic neoplasms and serous cystadenomas arising in the body-tail of the pancreas: MR imaging characterization

Abstract

• MCNs have macrocystic patterns, contrast enhancement of the peripheral wall and mural nodules • Microcystic pattern and central scar are suggestive of SCA • Mural nodules detected in MCNs correlate with epithelial dysplasia • Chronic obstructive pancreatitis is equally depicted in patients with MCNs and SCAs.

Cystic Neoplasm of the Pancreas

“…However, MRCP is capable to detect the lack of a communication between the cyst and the ductal system with a higher accuracy, thus an IPMN can be excluded. If a clinical history of pancreatitis is present, a diagnosis of pseudocyst should be excluded, and in this scenario EUS can be beneficial [16,17]. Large surgical series have shown that the risk of invasive cancer for MCNs is 3.9-11 % and the 5-year disease-specific survival is 100 % and 58-62.5 % for non-invasive and invasive tumors, respectively [11].…”

Radiological Workup of Cystic Neoplasms of the Pancreas

“…Atypical manifestations of serous cystadenoma include the oligocystic pattern (especially if cysts are greater than 2 cm), giant serous cystadenoma (>10 cm) that may exhibit compression of adjacent structures, ductal dilatation and other findings of obstructive chronic pancreatitis, and solid serous cystadenomas (composed of microscopic serous cysts) (figs. 2, 3) [20,21,29,30]. Even at MR imaging, solid serous cystadenoma may appear as a solid, well-circumscribed, well-vascularized pancreatic mass as the microscopic cysts are too small to be reliably depicted on MRI.…”

“…4). On T1-weighted MR images, however, the signal intensity may vary depending on the proteinaceous content of the mucin [5,30]. The typical T1 and T2 signal intensity may also be altered in case of intralesional hemorrhage (hyperintense on T1, mixed on T2), which is infrequently observed.…”

“…The cyst walls are usually thickened but may be smooth and thin. Peripheral curvilinear or eggshell calcifications may be seen in the wall or internal septa in up to 25% of cases and are better depicted on CT [2,26,30]. MCNs may grow slowly over time, at an average rate of 4 mm per year [33,34].…”

“…At imaging, an MCN commonly displays as a unilocular or septated cystic lesion with a thickened wall with clear margins [30]. The thick wall corresponds to fibrotic changes observed at histopathology.…”