Primary mediastinum immature teratoma with somatic-type malignant transformation (SM) is extremely rare, and the clinical prognosis is poor. Immature teratoma with SM is difficult to eradicate by chemotherapy due to poor sensitivity; therefore, surgical resection is recommended whenever possible because it may offer better survival.
Keywords: en bloc; primary mediastinum immature teratoma; somatic‐type malignant transformation; surgery.
© 2023 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd.