[A case of a patient with giant mucinous cystadenocarcinoma who presented with abdominal pain].

We report a case of a patient in whom a giant mucinous cystadenocarcinoma was treated with distal pancreatectomy. A 37-year-old woman was admitted to the hospital complaining of intermittent epigastric pain. The laboratory data revealed a marked increase in serum levels of carcinoembryonic antigen( CEA 22 ng/mL), cancer antigen( CA) 19-9( 258,129 U/ mL), and CA125 (53 U/mL). A computed tomography (CT) scan revealed a cystic tumor, 15 cm in diameter, in the body of the pancreas. The tumor presented as a multilocular cyst with enhanced nodules. On positron emission tomography (PET)-CT,[ 18F] fluorodeoxyglucose uptake by the nodules of the cyst was noted. Under the diagnosis of malignant mucinous cystic neoplasm, we performed distal pancreatectomy, splenectomy, partial gastrectomy, and left adrenalectomy because the tumor was suspected to be invading the stomach and left adrenal gland. The tumor was histologically diagnosed as invasive mucinous cystadenocarcinoma with ovarian-like stroma. The patient survived for 14 months after surgery without tumor recurrence. Invasive mucinous cystadenocarcinoma of the pancreas has high rates of lymph node metastasis and early recurrence after surgery. We believe that we would have had to perform complete tumor resection equivalent to that of invasive ductal carcinoma of the pancreas if the mucinous cystic neoplasm was found to be malignant preoperatively.