Myxoid Liposarcoma Metastasizing to the Parotid Gland.

Myxoid liposarcoma (MLPS) of the parotid gland is very rare, and only a few cases have been reported worldwide. It can be difficult to diagnose this disease when there is only a single lesion in the patient's body. A 56-year-old man was diagnosed with an MLPS in the left calf and was treated with wide resection. Two months after the surgery, a painless mass appeared in the man's left parotid gland area. Both fine-needle aspiration biopsy before surgery and intraoperative frozen sections suggested that the tumor was likely to be a pleomorphic adenoma. Both parotid ultrasound and CT indicated the same result. However, this mass was confirmed to be metastasis of MLPS through immunohistochemistry and multicolor fluorescence in situ hybridization. The authors report a case in which an MLPS metastasized to the parotid gland; this type of lesion is extremely rare and highly worthy of consideration because the authors misdiagnosed it.