Contrast-enhanced multiphasic CT and MRI findings of adenosquamous carcinoma of the pancreas

ObjectiveThe objective was to retrospectively study computed tomography (CT) and magnetic resonance imaging (MRI) findings of adenosquamous carcinoma of the pancreas (PASC).Materials and MethodsTwelve patients (six women and six men; mean age, 61.3 years; range, 47–78 years) who presented with PASC as documented by pathologic examination underwent CT (n= 10) or both CT and MRI (n= 2) examination. Two radiologists evaluated the images and determined the location, size, margin, internal attenuation or signal intensity, contrast enhancement, and pattern for each tumor. Additionally, the presence of poorly enhanced areas, upstream main pancreatic duct (MPD) dilatation, pancreatic atrophy, and peripancreatic tissue metastasis were evaluated. Images were cross-referenced to surgical and pathologic findings.ResultsMasses were distributed throughout the pancreas (head, n= 6; body, n= 1; and tail, n= 5). The tumor size ranged from 2.4 to 5.5 cm with an average size of 3.7 cm. Eight (66.7%) masses were ill defined, and seven (58.3%) were partially exophytic. Twelve (100%) masses showed heterogeneous and poorly enhanced areas. The lesions showed weak (n= 5), moderate (n= 5), or intense (n= 2) progressive enhancement. The diameter of MPD in six patients ranged from 3.0 to 5.0 mm with an average of 3.7 mm. Pancreatic atrophy was not found. In 10 patients (83.3%), masses invaded the peripancreatic tissues. Two patients had metastatic liver disease at presentation.ConclusionPASC typically presented as an ill-defined, hypovascular mass with a poorly enhanced area, exophytic tendency, and peripancreatic tissue invasion. Lack of pancreatic atrophy and mild MPD dilatation were also distinct from common duct pancreatic adenocarcinoma.