A serous oligocystic adenoma of the head of the pancreas successfully treated by dome resection and chemocautery: a new approach to serous oligocystic adenoma

Serous oligocystic adenoma (SOA) is an extremely rare benign tumor and ill‐demarcated large cyst. We report a case of pancreatic SOA. During abdominal ultrasonography (US) for a routine health examination and computed tomography (CT), a 69‐year‐old woman was found to have a 9‐cm unilocular cyst located in the head of her pancreas. After a 2‐year follow up, the cyst was seen to increase in size. The results of US, CT, magnetic resonance imaging, endoscopic retrograde cholangiopancreatography (ERCP), and angiography led to suspicion of a benign or low grade malignancy cystadenoma of the pancreas adjacent to the peripheral organs. Fluid analysis and frozen section pathological studies revealed a serous oligocystic adenoma with no malignancy. Dome resection, chemocautery, and omental filling were performed, and the postoperative course was uneventful. SOAs are difficult to diagnose without surgery. When the cyst exists in the head of the pancreas, adjacent to the biliary tract, portal system, or visceral vessels, it is also difficult to perform complete resection without the threat of morbidity or mortality. We have developed a new approach to SOA diagnosis and treatment that involves minimally invasive procedures.