Answer: Calcified Pancreatic Pseudocyst
There were 2 large calcified pseudocysts, 1 at the pancreatic head and 1 at the pancreatic tail. The calcified pseudocyst at the pancreatic tail was so heavily calcified that it could be seen on plain film x-ray. After admission to our unit, the patient's pain subsided and he subsequently signed himself out against medical advice. He came back to our unit a couple of months later and had another computed tomographic scan, which revealed a persistent, large pseudocyst at the pancreatic tail, but the pseudocyst at the pancreatic head had largely resolved. We performed endoscopic, ultrasound-guided cystogastrostomy. He was symptom free for 4 months afterwards. There was no evidence of recurrent pseudocyst on follow-up ultrasound examination.
Extensive calcification of a pancreatic pseudocyst to the extent that it is visible on plain abdominal x-ray is rare.1-3Differential diagnoses of such calcified lesions include tumors, cysts, hematomas, and abscesses, which arise from the pancreas, liver, kidney, adrenal gland, stomach, spleen, retroperitoneum, and small and large bowel. Computed tomography is helpful in delineating the origin of the lesion. In the present case, history of possible pancreatic trauma and the elevated serum amylase level are hints that point to the diagnosis.
Tumors arising from the pancreas can have a cystic appearance with calcified walls. Cystadenoma and cystadenocarcinoma of the pancreas are associated with calcification in 10% of cases, usually presenting as a radiating sunburst pattern.1It is not uncommon for solid pseudopapillary tumors of the pancreas to have both calcified and cystic areas. Other rare causes include cavernous lymphangiomas of the pancreas and cysts caused by Echinococcus granulosusspecies.
The same treatment that is used for pseudocysts can be used to treat calcified pseudocysts. Management options available for pancreatic pseudocysts include endoscopic, radiologic (percutaneous), surgical (open or laparoscopic), and expectant treatment.4The cyst can either be resected or treated by internal or external drainage. Choice of treatment option depends on whether the cyst is symptomatic, site of cyst, whether there are complications like infection, rupture, or bleeding, and whether there are coexisting pancreatic pathologic findings that need treatment. Percutaneous external drainage is good for an infected pseudocyst, but it may lead to chronic pancreatocutaneous fistula if there is contact with the pancreatic duct. Endoscopic internal drainage is a relatively new technique and is restricted to selected cases that are accessible by endoscope. It has the advantage of avoiding general anesthesia and abdominal wounds. However, problems like bleeding, inadequate drainage, and stent migration still occasionally occur. Surgery remains the definite treatment for pseudocysts in many cases. It allows resection and internal or external drainage to be carried out as appropriate. Laparoscopic internal drainage has also been described as a way to minimize wound trauma. However, the associated trauma due to surgery remains quite substantial and some patients are too frail or otherwise unfit for surgery and anesthesia.
Calcification of a pancreatic pseudocyst implies a chronic process and chance of spontaneous resolution is unlikely. Although risk of rupture is less, the chronic nature of a calcified cyst makes it commonly a nidus for infection.3For calcified pseudocysts, both surgical excision and surgical, internal drainage have been described with good results.1,3With the recent advance of the endoscopic pancreatic pseudocyst drainage technique,4the thick calcified wall is no longer an obstacle in performing such a procedure and it led to good results in our patient.
Correspondence:Paul Bo San Lai, FRCSEd, MD, Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong (paullai@cuhk.edu.hk).
Accepted for Publication:May 2, 2005.