New York Association of Neuropathologists
		      
Case involved  an orbital mass in a 15 year old female.  The mass involved the right sphenoid and  ethmoid sinuses, optic canal, anterior skull base and right medial  maxilla.  It was biopsied in Manhattan and resection carried out in Brooklyn.    Slides showed a vascular, bone forming  tumor with lamellar bone and nidus of woven bone.  There were rare mitoses.  There were occasional osteoclasts.  The differential diagnosis includes  osteosarcoma, fibrous dysplasia, meningioma, osteoid osteoma (but the mass is  >2 cm), and osteoblastoma.  
                
              
This mass was diagnosed as a “meningioma” in Manhattan.  This mass was called “Fibro-osseous lesion  consistent with cementifying variant of ossifying fibroma” by Dr. May Parisien  of Columbia.  This entity has also been called “aggressive  psammomatoid ossifying fibroma” and “cementifying fibroma.”  This is a locally invasive often (30-58%) recurrent  lesion that does not metastasize and for which total excision is the treatment  of choice.  It arises in the nasal  sinuses and orbit (70%) and also in the palate and anterior fossa.  It may show intracranial extension.  It is most common in teenagers (15 years old)  but has been reported from 5-54 years of life.   The male/female ratio is 1.3/1.  It  is EMA negative but CK may be positive.   Vimentin is positive.  Reticulin  occurs around woven bone.  If you  polarize the lesion you well see woven and lamellar bone.  The question may be asked, do reports of “Sino  nasal psammomatous meningioma” really refer to this entity?
		        
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