The clinical manifestations of the disease lacked specificity,and the clinical symptoms were nasal obstruction,any blood in snivel and slightly swelling pain on face.The neoplasm with unsmooth surface looked taupe and maroon,and was brittle and easy blooding.Paranasal sinus CT:crumbly mass lesion within the shadow filled in the left side of the maxillary sinus,and the sinus stopped up,sinus wall bone was absorptted and thinned, front and rear wall and inner wall bone were boundednessly broken off,knuckled partly to the nasal cavity.Direct reinforcement MRI:in addition to the result of paranasal sinus CT,enhance examination found obviously asymmetrical intensify of the focus.The pathological diagnosis of poatoperation was malignant melanoma on the left side of the maxillary sinus.