The abrupt pancreatic duct cutoff sign on MDCT and MRI

To evaluate the pancreatic duct cutoff sign in detecting pancreatic adenocarcinoma using CT and MRI.

A retrospective analysis of patients with a pancreatic duct (PD) cutoff sign on CT or MRI from 2000 to 2019 was performed. The primary outcome measured was the presence or absence of a malignant pancreatic tumor. Variables evaluated included imaging characteristics of patients with a malignant versus non-malignant cause of duct cutoff and included PD size and PD-to-parenchyma ratio, contour abnormality, abnormal enhancement, diffusion abnormality, and upstream parenchymal atrophy.

Seventy-two patients (44:28 M:F, mean age 64 years) were identified with a PD cutoff sign. Fifty-eight percent (42/72) of these patients were diagnosed with malignancy, 62% (26/42) of whom were diagnosed with pancreatic ductal adenocarcinoma. In patients diagnosed with a non-malignant cause of duct cutoff, 37% (11/30) were diagnosed with chronic pancreatitis. Eighty-eight percent (37/42) of patients with malignant causes and 33% (10/30) of patients with non-malignant causes were noted to have an associated mass on imaging. The presence of contour abnormality, diffusion abnormality, or abnormal enhancement at the level of the pancreatic cutoff was significantly higher in patients with malignancy (p < 0.05). There was no difference between groups in location of the pancreatic duct cutoff, degree of pancreatic duct dilatation, PD-to-parenchyma ratio, or presence of upstream atrophy.

Abrupt cutoff of the pancreatic duct was associated with an increased likelihood of detecting malignancy. All patients who demonstrate this sign should undergo expedited workup with dedicated MRI and EUS with biopsy.