An unusual case of recurrent huge primary mediastinal dedifferentiated liposarcoma

INTRODUCTION: Primary mediastinal dedifferentiated liposarcoma is an extremely rare malignant mesenchymal neoplasm composed of lipogenic tissue. It can be huge enough to compress heart and surrounding organs leading to clinical symptoms. PRESENTATION OF CASE: We present a case of huge primary mediastinal dedifferentiated liposarcoma in a 54-year-old man, confirmed by immunohistochemistry staining, who received surgical removal. However, six months later, the tumor recurred, and the patient underwent chemotherapy for 6 cycles resulting in stable disease. Six months after the last visit, the tumor showed no sign of recurrence anymore. DISCUSSION: Among the various subtypes, the dedifferentiated mediastinal liposarcoma is the least found type of liposarcoma and often leads to misdiagnosis. Challenges occurred not only in diagnosis but also in treatment since it frequently grows back and chemotherapy may be needed after surgery. CONCLUSION: This is a highly rare case of huge mediastinal liposarcoma that recurred after surgery and gave a satisfying outcome after chemotherapy.