Mucinous Cystic Neoplasm of the Liver in a Teenager: A Case Report.

Mucinous cystic neoplasms of the liver (MCN-Ls) are rare cystic liver tumors. Herein, we report a case of MCN-L wherein complete surgical resection was successful. A 17-year-old girl initially presented to the referring hospital with a chief complaint of upper abdominal pain. Abdominal computed tomography (CT) revealed a cystic lesion in the medial segment of the liver. After eight months, the cystic lesion showed a tendency to increase in size, and the patient was referred to our hospital. CT showed a cystic lesion with dilation of the left hepatic duct and duct of the right anterior segment. Magnetic resonance imaging and abdominal ultrasonography revealed a multilocular cyst. Endoscopic retrograde cholangiopancreatography revealed sclerotic changes, dilatation, and irregular wall features in the left hepatic duct. No communication between the cystic lesion and the biliary system was observed; there was no evidence of biliary prolapse. A left hepatectomy and cholecystectomy were performed. Histological examination revealed an ovarian-like stroma (OLS); the lesion was diagnosed as MCN-L. The patient was recurrence-free six months postoperatively.To our best knowledge, this is the second reported case of teenage-onset MCN-L. We report the development of MCN-L in a teenager, highlighting the potential of this rare tumor for manifesting even at a young age. Our case demonstrated that MCN-L, despite its typically benign nature, should be carefully monitored. Although most cases of MCN-L do not require immediate surgery, timely surgical intervention may be necessary in cases of rapid growth or persistent symptoms.