Background:
Mature cystic teratoma is one of the most common tumors of the ovaries; however, primary retroperitoneal lesions are rare entities in adults.
Case summary:
We report a case of a 33 year-old woman noticing a mass in her epigastric and left upper abdominal region without any specific signs and symptoms. Radiological evaluation revealed a retroperitoneal mass with extension from the posterior aspect of the pancreas to the pelvic cavity, composed of calcifications and cystic elements.
Conclusion:
The tumor was resected through a midline laparotomy and the pathology report confirmed the diagnosis of a mature cystic teratoma with no evidence of malignancy or immature components.