Recurrent massive myxoid liposarcoma in retroperitoneum 10 years post initial operation

INTRODUCTION: Myxoid liposarcoma tends to be a relatively good prognosis. Follow‐up is recommended once a year from the 5th year after surgery. CASE PRESENTATION: A 48‐year‐old man had a massive retroperitoneal tumor, measuring approximately 20 cm. Resection of a huge myxoid liposarcoma had been performed on his back 10 years ago and the weight of the mass was 14 kg. The tumor was resected from the right kidney and its weight was 3.6 kg. Pathological examination showed myxoid liposarcoma and therefore, the tumor was diagnosed as recurrent. But after the resection, no recurrence or metastasis was observed. CONCLUSION: To our knowledge, the case presents the first report where both initial and recurrent tumors were massive and the time for recurrence was 10 years. Therefore, a follow‐up of myxoid liposarcoma might have to be done cautiously throughout the patient's life.