Psammomatoid ossifying fibroma of the ethmoid

We present a 16 year-old girl who suffered since one year of a painless slow growing mass on the left medial orbital rim causing globe displacement. CT-scan and MRI of the orbit with T1 and T2 weighted images showed the presence of a large mucocoele in the frontal sinus. This occurred secondary to the obstruction of the sinonasal tract by a bony tumour. Histopathology showed a lesion consisting of fibrous tissue and ossicles or psammomatoid bodies. The diagnosis of a psammomatoid ossifying fibroma (POF) was made.