Macrocystic serous adenoma of the pancreas

Differential diagnosis of pancreatic serous oligocystic adenoma and mucinous cystic neoplasm with spectral CT imaging: initial results

AIM

To investigate the imaging characteristics of pancreatic serous oligocystic adenoma (SOA) and mucinous cystic neoplasms (MCNs) using spectral computed tomography (CT) and to evaluate whether quantitative information derived from spectral imaging can improve the differential diagnosis of these diseases.

MATERIALS AND METHODS

From February 2010 to June 2013, 44 patients (24 SOAs and 20 MCNs) who underwent spectral CT imaging were included in the study. Conventional characteristics and quantitative parameters were compared between the two disease groups. Logistic regression was used for multiparametric analysis. The receiver-operating characteristic curve was used to evaluate the diagnostic performance of single parameter and multiparametric analysis. Two radiologists diagnosed the diseases blinded and independently, without and with the information of the statistical analysis.

RESULTS

Tumour location, contour, size, and monochromatic CT values at 40 keV to 70 keV, iodine concentration, and effective atomic number (effective-Z) in the late arterial phase were the independent factors correlated with category. Multiparametric analysis with logistic regression showed that tumour size, location, and contour were the most effective variations, and obtained an area under the ROC curve (AUC) of 0.934. With the knowledge of statistical analysis, the accuracy of the first reader increased from 70.5% to 86.4%, and the accuracy of the second reader increased from 81.8% to 90.9%.

CONCLUSIONS

Although CT spectral imaging provided additional information and multiparametric analysis obtained better performance than single-parameter analysis in differentiating MCNs from SOAs, multiparametric analysis with the combination of quantitative parameters derived from CT spectral imaging did not improve the diagnostic performance. Tumour size, location, and contour played an important role in differentiating MCNs from SOAs.

Comparative immunohistochemical study of the stroma of serous and mucinous cystic neoplasms: possible histopathogenetic relationship of the 2 entities

OBJECTIVES

Serous and mucinous cystic neoplasms (SCNs/MCNs) are the most common true cystic neoplasms of the pancreas and occur more frequently in women. The aim of this study was to characterize the stroma of SCNs to compare its phenotype with that of MCNs.

METHODS

A total of 12 SCNs and 5 MCNs were analyzed immunohistochemically using the following antisera: progesterone receptor (PR), estrogen receptor (ER), inhibin, CD10, and vimentin. Normal pancreatic tissue (17 cases) and ductal adenocarcinomas of the pancreas (3 cases) were used as controls.

RESULTS

Eight of 12 patients with SCNs and all 5 patients with MCNs were women. For SCNs, the stroma was sclerotic and paucicellular and showed focal moderate to strong reactivity for PR. Estrogen receptor, CD10, and inhibin were virtually negative. For MCNs, the stroma was more cellular and ovarianlike and showed a larger number of PR-positive cells with focal expression of ER and inhibin. Vimentin was expressed in all stromal cells in both groups.

CONCLUSIONS

Both SCNs and MCNs contain PR-positive stromal cells. In view of the aforementioned clinical and immunophenotypical similarities, we suggest that in SCNs and MCNs, the stromal framework is similar in origin and/or differentiation.

Management of serous cystadenoma of the pancreas

Serous cystadenoma of the pancreas is a diagnosis being entertained with increasing frequency. The histopathologic findings, diagnostic strategy, differential diagnosis, and treatment strategy of these generally benign but sometimes symptomatic lesions are discussed. Based on the available case series, surgical resection should be considered in good-risk patients with symptomatic tumors, with tumors at least 4 cm in maximum diameter, or in whom a more worrisome diagnosis cannot be excluded.

Serous cystadenoma of the pancreas: tumor growth rates and recommendations for treatment

OBJECTIVE

To define the natural history and optimal management of serous cystadenoma of the pancreas.

SUMMARY BACKGROUND DATA

Serous cystadenoma of the pancreas is the most common benign pancreatic neoplasm. Diagnostic criteria, potential for growth or malignancy, and outcomes are not well defined. As a result, management for patients with serous cystadenomas varies widely in current practice.

METHODS

A total of 106 patients presenting with serous cystadenoma of the pancreas from 1976-2004 were identified. Hospital records were evaluated for patient and tumor characteristics, diagnostic workup, treatment, and outcome. Twenty-four patients with serial radiographic imaging were identified, and tumor growth curves calculated.

RESULTS

Mean age at presentation was 61.5 years and 75% of patients were female. The most common symptoms were abdominal pain (25%), fullness/mass (10%), and jaundice (7%); 47% were asymptomatic. Mean tumor diameter was 4.9 +/- 3.1 cm, which did not vary by location. Tumors <4 cm were less likely to be symptomatic than were tumors > or =4 cm (22% vs. 72%, P < 0.001). The median growth rate in the patients who had serial radiography was 0.60 cm/y. For tumors <4 cm at presentation (n = 15), the rate was 0.12 cm/y, whereas for tumors > or =4 cm (n = 9), the rate was 1.98 cm/y (P = 0.0002). Overall, 86 patients underwent surgery, with one perioperative death.

CONCLUSIONS

Large (>4 cm) serous cystadenomas are more likely to be symptomatic. Although the median growth rate for this neoplasm is only 0.6 cm/y, it is significantly greater in large tumors. Whereas expectant management is reasonable in small asymptomatic tumors, we recommend resection for large serous cystadenomas regardless of the presence or absence of symptoms.

Unusual imaging appearances of pancreatic serous cystadenoma: correlation with surgery and pathologic analysis

BACKGROUND

We describe imaging and pathologic features of serous cystadenoma of the pancreas on multislice helical computed tomography CT (MS-CT) and surgical resection.

METHODS

Radiologic and pathologic features were analyzed in five patients. All patients underwent MS-CT and digital subtraction angiography (DSA), and four patients underwent magnetic resonance (MR) imaging. Preoperatively, three cases showed radiologic evidence of mainly solid appearance on MS-CT, and the suspected diagnoses were solid pancreatic tumors (patients 1-3). The other two cases showed radiologic evidence of macrocystic tumor of the pancreas, and the suspected diagnoses were mucinous cystic tumors (cases 4 and 5). All patients underwent surgery, and the diagnosis of serous cystadenoma was confirmed on pathologic examination.

RESULTS

In three cases that showed a solid appearance on MS-CT, a microcystic appearance was identified on microscopic examination, and the tumors were found to be hypervascular lesions on multiphasic contrast-enhanced CT and DSA. In cases 1 and 2, the lesions showed high intensity with internal septation on T2-weighted MR images. In two cases, the tumors were classified as a macrocystic variant of serous cystadenoma, and no mural nodules, papillary projections, or calcifications were seen in the tumors.

CONCLUSION

Imaging appearance of serous cystadenoma on MS-CT is various and sometimes indistinguishable from that of solid tumor or mucinous cystic tumors of the pancreas. Imaging findings of hypervascularity and a well-marginated high-intensity lesion with internal septation on T2-weighted MR imaging may be crucial to identify serous cystadenoma that contains no visible cystic compartments on MS-CT.

Serous oligocystic adenoma of the pancreas

Cystic neoplasms of the pancreas are uncommon lesions but are becoming increasingly prevalent. Herein we report a case of an oligolocular cystic lesion in the head of the pancreas in a young female that had undergone a cystenteroanastomosis 10 years ago. She underwent a duodenopancreatectomy with an uneventful recovery. The histology showed a serous oligocystic adenoma of the pancreas and the immunohistochemistry study confirmed the diagnosis. There is no sign of recurrence after the surgery. The role of pre-operative diagnosis based on tomographic, echoendoscopy and fine needle aspiration are discussed.