Teaching Case

A 73-year-old woman presented to our emergency department for left flank pain, dyspnea and peripheral oedema.

In her personal anamnesis there were Ulcerative Colitis and Chronic Pancreatitis with pseudocysts. She had a negative history of alcoholism.

Values of lipase, amylase and leucocyte were elevated. Cholestasis indexes unaltered.

A previous CT at our disposal shows Chronic Pancreatitis (CP)  with parenchymal atrophy, gross calcifications, dilatation of the ductal system and several pseudocysts, the largest of which is 32 mm at body level (Fig. 1).

A previous MR confirms CP (Fig. 2). In particular, the above mentioned pseudocyst connected to the pancreatic duct system can be observed.

At the onset of symptomatology, MRI  shows a large fluid collection near to pancreatic  body/tail (Fig. 3). MRCP shows that the collection is in communication with the body's pseudocyst and therefore with the ductal system. Free intraperitoneal fluid is associated.

These findings refer to a rupture of the body's pseudocyst, which was previously described, with the formation of an organized fluid collection and free effusion.

CP is characterized by continuing inflammation, destruction, and irreversible morphological changes in the pancreatic parenchyma and ductal anatomy.[1]

The end stage of CP is characterized by complications like pancreatic insufficiency (endocrine and/or exocrine), metabolic bone disease, adenocarcinoma, pseudocysts, splanchnic venous thrombosis,  duodenal or biliary obstruction. [2]

Pseudocyst is a localized fluid collection rich in pancreatic enzymes, surrounded by a wall of fibrous tissue not lined by epithelium.

Pseudocysts complicate the course of chronic pancreatitis in 30% to 40% of patients.[2]

The pathogenesis of pseudocysts is not well understood but seems to stem from disruptions of the pancreatic duct (PD) due to pancreatitis or trauma, followed by extravasation of pancreatic secretions. Two thirds of patients with pseudocysts have demonstrable connections between the cyst and the pancreatic duct. [3]

Clinical presentation of pancreatic pseudocyst can range from asymptomatic patient to major abdominal catastrophe due to complications.

Acute complications include bleeding (usually from splenic artery pseudoaneurysm), infection, and rupture.[3]

Spontaneous rupture of a pancreatic pseudocyst has been reported in less than 3% of cases.[4]

The released pancreatic enzymes can degrade anatomical barriers causing perforation, fistula with the surrounding viscera, infection, ascites, and hemorrhage.

In our case, the contents leaking from the spontaneous rupture of the pseudocyst was delimited by new fibrous tissue, which led to the formation of a defined collection in retroperitoneum.

Pseudocysts must be differentiated from other cystic tumors, like Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. In our case, the gastroenterologist ruled out IPMNs by performing an endoscopic ultrasound (EUS).

EUS offers the highest resolution of the pancreas and can aid in the differential diagnosis, classification  and differentiation between benign and malignant tumors.[5]

ERCP is the standard of reference for imaging the pancreaticobiliary system, but it is invasive and can be associated with serious adverse effects. [1][6]

CT scanning can demonstrate duct dilation, cystic lesions, huge fluid collection, multiple pancreatic pseudocysts and pancreatic calcification.[7]

MRI provides noninvasive pancreatic duct imaging and accurate characterization of pancreatic and peripancreatic pathology. Although CT is more sensitive than MRI for the detection of calcifications associated with CP, MRI best depicts intraductal stones and duct obstruction [8]. In addition, MRI can depict pseudocysts and can be used to characterize their content and thus to guide drainage.[8]

MRCP can noninvasively evaluate the pancreatic parenchyma and also delineate the pancreatic duct morphology. Therefore MRCP is an alternative for patients in whom ERCP failed and in those who cannot tolerate this procedure.[8] [9]

Written informed patient consent for publication has been obtained.