The CT findings of pancreatic acinar cell carcinoma in five cases

The aim of this study is to analyze the computed tomographic (CT) findings of pancreatic acinar cell carcinoma (ACC).

The CT features and clinical presentations of five patients (four men, one woman; mean age, 52 years) with pathology-proven pancreatic ACC were reviewed. The image characteristics included the lesion location and size, the exophytic nature of the tumor, intratumoral hemorrhage, calcification, the presence of cystic or necrotic components, bile or pancreatic duct dilation, attenuation on the noncontrast image, attenuation on the arterial- and venous-phase images, peripancreatic invasion, peripancreatic lymphadenopathy, and distant metastases.

The tumors were located at the pancreatic tail in three cases and at the pancreatic head in two cases. The average lesion size was 5.3 cm. Exophytic features and cystic/necrotic components were found in 80% (4/5) and 60% (3/5) of cases, respectively. The ACC showed a mild hypodense appearance on noncontrast CT in 100% (3/3) of cases and a hypodense appearance on arterial-/venous-phase CT in 80% (4/5) of cases. The exception was one lesion that showed a significantly hyperdense appearance and a mildly hyperdense appearance on the arterial- and venous-phase images. None of the CT images showed enhancement of a capsule, calcification, intratumoral hemorrhage, bile or pancreatic duct dilation, vascular encasement, or distant metastatic disease, but three cases showed peripancreatic invasion and lymphadenopathy.

With persistent mild enhancement, the typical ACC appears as an exophytic tumor with a focal cystic/necrotic component and the lack of ductal dilatation. The predilection for older male patients and elevated serum alpha fetoprotein are useful clinical features for confirming an ACC diagnosis.