Contributed by Kenneth Clark, MD and Teresa McHale, MD.
Published on line in April 2004
This is a female in her 50s who presented to the Emergency Department with severe right upper abdominal and flank pain, nausea, vomiting, fever, and chills. Past medical history was significant only for hypertension. Evaluation by CT-scan revealed a right ureteral stone with associated hydronephrosis. Urinalysis was positive for both blood and nitrites. She was hydrated, discharged home with both antibiotics and analgesics, and instructed to follow up with her primary care physician.
The following day she returned to the emergency department with markedly increased right flank pain, and persistent chills and fever. She was subsequently admitted for further evaluation. A repeat CT-scan of the abdomen confirmed the right ureteral stone. However, it also revealed a 4.3 X 1.9cm multiloculated, calcified, cystic lesion in the proximal to mid-body of the pancreas, possibly suggestive of a cystic neoplasm. There was no obvious communication with the pancreatic duct. A subsequent ultrasound of the pancreas confirmed these findings. She was taken to the operating room for a partial pancreatectomy.
GROSS PATHOLOGIC FINDINGS:
Received is an intact portion of mid-pancreas measuring 12.0 X 5.0 X 4.0 cm. Clearly visible on the surface of the specimen, abutting the margin of resection, is a 2.4 cm thin-walled cyst, filled with clear fluid. Serial sectioning (every 0.5cm) along the long axis of the specimen shows the cyst to be part of a multiloculated cystic mass that measures 4.0 X 2.4 X 2.0 cm in overall dimension. The sizes of the loculations range from 0.4 to 2.4 cm. The border of the mass is lobulated, with no gross evidence of infiltration of adjacent pancreatic parenchyma. There is no definite evidence of communication with the pancreatic duct or neighboring vessels. All of the cysts have a smooth inner surface, with no visible papillary structures, and contain clear serous fluid. The remainder of the pancreatic parenchyma is tan, lobulated, and shows no gross abnormalities.
MICROSCOPIC PATHOLOGIC FINDINGS:
Low power magnification shows numerous thick-walled cystic structures abutting normal pancreatic parenchyma (Figures 1 and 2). In some areas, the walls of the cystic structures create an irregular border with the surrounding pancreatic parenchyma, causing compression of neighboring structures such as vessels and pancreatic ducts, but with no evidence of invasion. Higher power magnification shows the single-layered epithelium of the cysts to consist of cuboidal (and sometimes flattened) cells. The nuclear contours were round, regular, and located at various levels within the cells (basally, mid-cell, and apically). The cytoplasm is completely clear and a number of epithelial cells show bulging apical membranes (Figures 3 and 4). PAS stain, before and after diastase, confirms the presence of glycogen within the epithelial cells (Figures 5 and 6). The epithelium nowhere shows invasion into the underlying fibrous stroma.