CT Findings of Acinar Cell Carcinoma of the Pancreas: Focused on Spiral CT Findings

ABSTRACT

PURPOSE: To evaluate the CT findings (in particular, those of dual-phase spiral CT) of acinar cell carcinoma of the pancreas. MATERIALS AND METHODS: We retrospectively reviewed the CT findings of pathologically confirmed pancreatic acinar cell carcinoma in seven patients (M:F = 4:3) aged 26 -57 (average,46) years. Serum amylase and lipase were clinically checked, and concomitant subcutaneous nodules or osteolytic bony lesions were evaluated. Contrast-enhanced CT scanning. was performed in seven cases, and in four of these, dual-phase spiral CT scans were also obtained. Tumor size and location, the extent of intratumoral necrosis, calcification, contour, margin, capsule, adjacent organ invasion, lymphadenopathy, hepatic metastasis and enhancement pattern were analyzed. RESULTS: Serum lipase was elevated in three cases, but in all, the serum amylase range was normal. In no case were subcutaneous nodules or osteolytic bony lesions observed. The size of the mass was 5 -18 (mean 8.4 cm), and tumors were located in the tail (n=3), body (n=2) and head (n=1), with one involving both the body and tail. Intratumoral necrosis was noted in six of seven cases and calcification in two. A lobulated contour with capsule was observed in six, and in two there was splenic invasion. In three of four cases in which dual-phase spiral CT was performed, the enhancement pattern was high during the arterial phase and isodense with normal pancreatic parenchyma during the venous phase. In two cases involving spiral CT, multiple hyperattenuated hepatic metastasis was observed during the arterial phase. In three cases in which conventional post-contrast CT was performed, the tumor showed low enhancement. CONCLUSION: Pancreatic acinar cell carcinoma is rare, but if a large, well encapsulated, strongly enhanced pancreatic mass showing central necrosis is observed during the arterial phase of dual-phase spiral CT, and metastatic nodules are also present, pancreatic acinar cell carcinoma should be differentiated from other pancreatic neoplasms.