Mature cystic teratoma of the pancreas with 30 years of clinical course: A case report.

Rationale: Mature cystic teratoma of the pancreas is an extremely rare condition that is challenging to manage due to inadequate preoperative histological diagnosis. Patient concerns: A 36-year-old female was admitted to our hospital because of a complaint of worsening paroxysmal abdominal pain for over a year. She was diagnosed with pancreatic pseudocyst and underwent five surgical procedures (i. e., four external drainage and one internal drainage procedures) in the last 30 years. Diagnoses: Intraoperative frozen section analysis identified the tumor as a cystic teratoma, and pathological evaluation confirmed it to be a mature cystic teratoma. Interventions: Explorative laparotomy was performed, and the tumor was then resected completely through with partial pancreatectomy, left colon resection, partial gastrectomy, duodenectomy, as well as inferior vena cava and renal vascular repair. Outcomes: The patient exhibited a generally good wellbeing without any recurrence during the 6 months of follow up. Lessons: This case demonstrated the significant impacts of misdiagnosis and inappropriate treatments for benign disease on the patient's quality of life and highlighted the importance of early surgical resection with a definitive pathological diagnosis for pancreatic cystic teratoma.