Imaging Pearls ❯ Pancreas ❯ Acinar Tumors
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- Objective: Evaluation of the imaging features of pathology- proven acinar cell carcinomas (ACCs) of the pancreas using computed tomography (CT).
Results: The ACCs in this series were evenly distributed between the head/uncinate and the tail, were predominantly exophytic (73%), tended to be large (average size 5.1 cm), and were mostly hypodense to the surrounding pancreas on both the arterial and venous phase images. A sizeable proportion demonstrated a cystic or necrotic component (53%) and/or an enhancing capsule (53%). Of those lesions in the head or uncinate process, very few resulted in pancreatic (28%) or biliary (14%) ductal dilatation. None of the lesions in this series showedinternal calcification or intratumoral hemorrhage.
Conclusion: While a prospective diagnosis is difficult, ACCs have several features which can differentiate them from ductal adenocarcinoma, including their large size, lack of biliary or pancreatic ductal dilatation, exophytic nature, and the presence of an enhancing capsule. - A rare neoplasm of the pancreas with differentiation that recapitulates acinar cells, acinar cell carcinoma (ACC)accounts for less than 1% of all pancreatic neoplasms. The tumor is classically seen in older men, usually over the age of 50, who rarely can present with a unique syndrome characterized by skin rashes, polyarthragias, fevers, and fat necrosis (‘‘lipase hypersecretion syndrome’’).
Acinar cell carcinoma of the pancreas: computed tomography features--a study of 15 patients.
Raman SP, Hruban RH, Cameron JL, Wolfgang CL, Kawamoto S, Fishman EK.
Abdom Imaging. 2013 Feb;38(1):137-43. doi: 10.1007/s00261-012-9868-4. PMID: 22349806. - Reviewing these cases, although the vast majority of these tumors were hypodense on the arterial and venous phase images relative to the normal pancreatic parenchyma, several features retrospectively made the diagnosis of DAC less likely: (1) large size, with a mean maximum diameter of 5.1 cm (as opposed to a mean size of 2-3 cm for DAC) [4]; (2) exophytic nature of the tumor; (3) the presence of a well-defined enhancing capsule (53%); (4) cystic or necrotic change (53%); (5) the lack of significant biliary or pancreatic ductal dilatation,despite the presence of a fairly large mass at the pancreatic head or uncinate process; and (6) a relative lack of vascular encasement or narrowing (20%).
Acinar cell carcinoma of the pancreas: computed tomography features--a study of 15 patients.
Raman SP, Hruban RH, Cameron JL, Wolfgang CL, Kawamoto S, Fishman EK.
Abdom Imaging. 2013 Feb;38(1):137-43. - In conclusion, the imaging diagnosis of ACC is extremely difficult to make prospectively. In fact, the diagnosis of ACC was not considered in the initial radiology reports for any of the 15 patients in our series, while a number of other diagnoses were considered, including DAC, neuroendocrine tumor, lymphoma, and cystic pancreatic neoplasm. However, the lesions in this study had several features in common, which we believe to be suggestive: When confronted with a large, exophytic, well-circumscribed mass arising from the pancreas, often without appreciable biliary or pancreatic ductal dilatation, the diagnosis of ACC should be considered.
Acinar cell carcinoma of the pancreas: computed tomography features--a study of 15 patients.
Raman SP, Hruban RH, Cameron JL, Wolfgang CL, Kawamoto S, Fishman EK.
Abdom Imaging. 2013 Feb;38(1):137-43.
- "Pure acinar cell carcinoma of the pancreas is usually an exophytic, oval or round, well marginated, and hypovascular mass on CT and MRI. It typically is completely solid when small and contains cystic areas due to necrosis when large."
CT and MRI Features of Pure Acinar Cell Carcinoma of the Pancreas in Adults
tatli et al.
AJR 2005; 184:511-519
- Acinar Cell Carcinoma of the Pancreas
- 1% of pancreatic cells are acinar cells
- 5th thru 7th decade of life
- Tumor cells may produce pancreatic enzymes that circulate systemically and cause polyarthritis and subcutaneous fat necrosis
- Aggressive tumor with mortality less than adenocarcinoma
- Acinar Cell Carcinoma of the Pancreas
- Pancreatic head is most common site
- Lesions are usually solid and exophytic
- Mean size around 7 cm
- Presentaion may be palpable mass, abdominal pain or weight loss