Cystic tumor of the pancreas

Clinical History

We describe a case of a 55-year-old female, with epigastric pain and vomiting for the last two months. Abdominal ultrasound and a CT showed the presence of a cystic mass in the pancreatic body and tail, without secondary lesions. After surgery, the pathologist stated that the lesion was a mucinous cystadenoma.

Imaging Findings

The 55-year-old female was referred to our hospital with complaints of epigastric pain and vomiting with two months of evolution. A physical examination was done, which depicted the presence of an ill-defined non-tender epigastric mass, with fluctuation. The laboratory data showed that there were no significant changes. An ultrasound examination showed that the mass, measuring maximum 15 cm in diameter, arose from pancreatic tail and body and had a liquid nature, with multiple thin internal septations, defining cystic spaces with more than 2 cm (Fig. 1). Better characterization was achieved with abdominal CT that depicted the low attenuation mass, with well-defined borders, thin internal septations that enhance after an intravenous administration of contrast media, without mural nodules, calcifications or apparent secondary lesions (Figs. 2,3). The patient underwent a partial pancreatectomy along with splenectomy, and the pathologist stated that the lesion was a mucinous cystadenoma of the pancreas. The patient remained in clinical and radiological surveillance for two years.

Discussion

Cystic neoplasms of the pancreas account for less than 5% of the pancreatic tumors and 10% of the pancreatic cystic lesions [1]. Mucinous tumors mainly affect females between the age group of 40 and 60 years. They are usually localized in the body and the tail of the pancreas and are formed by less than six cysts with more than 2 cm. They have peripheral calcifications in 20% of the cases and show enhancement in the septa after an intravenous administration of contrast media [2]. Histopathologically, these tumors are divided into benign (mucinous cystadenoma), borderline and malignant (mucinous cystadenocarcinoma). On sonograms, mucinous cystadenoma appears as a well-defined predominantly cystic mass, with internal septations and occasionally peripheral calcifications. Mural nodules and solid components may be seen, particularly in malignant forms (mucinous cystadenocarcinoma) [3]. The abdominal CT done with an intravenous administration of contrast media depicts the characteristics reported previously, but can have significant interest in differential diagnosis with cystadenocarcinoma (malignant form), by excluding the presence of thick septations, mural nodules, hepatic lesions and peritoneal carcinomatosis [4]. On gadolinium-enhanced T1-weighted fat-suppressed images, large, irregular cystic spaces separated by thick septa are demonstrated [5]. Mucin produced by these tumors may result in high signal intensity on T1- and T2-weighted images of the primary tumor and liver metastases. Liver metastases are generally hypervascular and have an intense enhancement on immediate post-gadolinium images [6]. Mucinous cystadenomas show no evidence of metastases or invasion of adjacent tissues. The mucinous cystadenocarcinoma may be very locally aggressive with an extensive invasion of the adjacent tissues; however, the absence of the demonstration of tumor invasion does not exclude the malignancy [6]. The aspiration of the cystic fluid with cytological analysis and the determination of viscosity, amylase, CEA, Ca 72-4, Ca-125, and Ca 15-3 can be of great value in the characterization of cystic lesions in the pancreas [7]. Those parameters can help in distinction between pseudocysts versus neoplasms and between different kinds of cystic neoplasms. The level of amylase is high only in pseudocysts, and all the other markers are low. Ca15-3 value of 30 U/ml was 100% sensitive and specific in differentiating histological benign and malignant mucinous neoplasms [8]. In a study, Hammel [9] showed 98 % specificity for a CA 72-4 level greater than 40 U/ml in distinguishing mucinous neoplasm from pseudocysts and serous cystadenomas. Viscosity is only elevated in pseodocyst’s and serous cystadenomas. Cytolology may be helpful when depicts epithelial cells, because pseudocyst’s wall don’t have a epithelial lining. The available evidence seems to indicate that mucinous cystic neoplasm’s are potentially, and perhaps inevitably, malignant tumors, so surgical excision is recommended.

Differential Diagnosis List

Final Diagnosis

Mucinous cystadenoma of the pancreas.

URL:	https://www.eurorad.org/case/3748
DOI:	10.1594/EURORAD/CASE.3748
ISSN:	1563-4086