Rationale:
Reports of mature cystic teratomas (MCTs) with associated complications and changes in serum cancer antigen levels are rare. Herein, we report a rare case of MCT with associated complications (rupture and malignant transformation), high levels of serum cancer antigens (CA19-9, CA12, and CEA), and surgical therapy.
Patient concerns:
An 81-year-old woman was referred to our emergency department because of diffuse abdominal pain and distension for 20 days.
Diagnoses:
Imaging findings, including transabdominal ultrasonography, computed tomography, and magnetic resonance imaging, revealed a complex solid cystic mass in the lower abdomen. Preoperative laboratory test results showed high levels of serum cancer antigens (CA19-9, CA12, and CEA) in MCT. Histopathological examination of the specimen revealed a MCT with rupture and malignant transformation.
Interventions:
The patient underwent a total abdominal hysterectomy, bilateral oophorectomy, and partial omentectomy. The patient did not undergo chemotherapy after surgery.
Outcomes:
The follow-up period was 12 months. The patient recovered well without focal local recurrence or distant metastasis after the surgery.
Lessons:
The study aims to report a new case of MCT with associated complications (rupture and malignant transformation) and changes in serum cancer antigen levels. Although this tumor presents as a complex solid cystic mass, detection of the intratumoral fat component is a key diagnostic imaging feature. A high level of serum cancer antigen may indicate the malignant transformation of MCT. In this case, surgery was an effective treatment for the MCT.