Abstract
INTRODUCTION: Primary mediastinal embryonal carcinoma is a disease characterized by pathological features similar to those of stem cell malignancies. Due to its undifferentiated nature and the potential for extensive metastasis, the prognosis of this disease is usually poor. Its overall incidence rate is less than 0.2/100,000 individuals, primarily affecting young adults aged 15 to 35, with a higher prevalence among males. The 5-year survival rate is less than 30%. CASE PRESENTATION: In this report, we report a 28-year-old man with a large anterior mediastinal tumor who underwent resection of the anterior mediastinal tumor after imaging and focal puncture biopsy. The final diagnosis was primary mediastinal embryonal carcinoma. This patient has been in long-term survival without recurrence for 8 years after surgery, during which he regularly received treatment and underwent follow-up. CONCLUSION: In the diagnosis and treatment of primary mediastinal embryonal carcinoma, changes in AFP levels are highly relevant and can be used to evaluate the outcome of surgery. At the same time, patients should also receive a complete treatment plan.