Giant Pancreatic Cyst: An Unusual Entity

A 74-year-old woman was referred for further evaluation of a large pancreatic cystic lesion. She presented with abdominal discomfort, without weight loss, anorexia or history of pancreatitis or abdominal trauma. Physical examination revealed a large epigastric mass. A contrast-enhanced computed tomography (CT) showed a huge, well-defined, multiloculated cyst of 12 cm in greatest dimension arising from the pancreatic body, with multiple wall calcifications, without typical imaging features of a particular pancreatic cystic neoplasm (Fig. 1). Endoscopic ultrasound (EUS) showed a multilocular cyst with a larger cyst (120 mm × 70 mm) and a peripheral microcystic component (Fig. 2). EUS-guided fine-needle aspiration of 7 mL of serous cystic fluid was performed from the largest cyst under prophylactic IV antibiotics. The sample had no malignant or mucus-producing cells and CEA (<2.5 ng/mL) and amylase (41 U/L) were within the reference values, making a serous cystadenoma the most likely diagnosis. Due to persistent epigastric discomfort, a distal pancreatectomy and splenectomy was performed (Fig. 3). Macroscopic examination of the resected specimen showed a combination of large cysts with several small cysts. On microscopy, the cysts were lined with a single layer of cuboidal epithelial cells with clear cytoplasm, PAS positive (Fig. 4). Histopathological examination confirmed the diagnosis of a pancreatic serous oligocystic adenoma.

Figure 1.

Computed tomography: giant well-defined multiloculated cystic mass in the body of the pancreas.

Figure 2.

Endoscopic ultrasound: large multilocular cyst (A) with a microcystic pattern component (B).

Figure 3.

Macroscopic appearance of the resected pancreatic cyst.

Figure 4.

Microscopic appearance of the pancreatic cyst wall with a single layer of cuboidal epithelial cells with clear cytoplasm (H&E 100×).

Serous oligocystic adenoma (SOA) is a rare benign pancreatic tumor which represent an atypical macroscopic morphologic variant of serous cystadenomas (SCA).¹ SOAs are characterized by a limited number of cysts with a diameter of >2 cm and share imaging features overlapping those of mucinous cystic neoplasm (MCN) and branch-duct intraductal papillary mucinous neoplasm (BD-IPMN), thus frequently making the radiologic diagnosis difficult.² Endoscopic ultrasound and cyst fluid aspiration have a role in distinguishing mucinous and serous lesions.³ Management is determined by the presence of symptoms. Giant serous cystadenomas are also rare; this term usually refers to a multicystic tumor larger than 10 cm in diameter in comparison with a described mean tumor diameter of 5 cm.⁴

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