We reported a case of psammomatoid ossifying fibroma of the sinonasal tract. The patient was a 39-year-old woman complaing of a swelling of the right cheek. MRI and CT demonstrated a large mass (48×30×40 mm) with a heterogeneous contrast effect. The mass was diagnosed as a benign tumor based on a biopsy performed in the outpatient clinic. Therefore, the tumor was dissected by endoscopic sinus surgery. After the surgery, the tumor was diagnosed as a psammomatoid ossifying fibroma by histological analysis. Psammomatoid ossifying fibroma shows an invasive growth pattern, although the tumor is categorized as benign. The tumor may remain in the skull base. Thus, we are planning a Subsequent operation as radical surgery. Psammomatoid ossifying fibroma of the sinonasal tract is very rare.
