69-years-old Bosnian woman was admitted two weeks ago at the Department of Neurosurgery, Clinical Center Sarajevo, Bosnia and Herzegovina because of the tumor mass that rapidly had developed within several months and infiltrated her frontal and ethmoidal sinuses (radiology scan revealed osteolytic mass, not shown here). Intraoperativelly, the surgeon removed well-vascularized, infiltrative tumor mass that invaded not only both sinuses but also dura.  
Microscopically, the tumor was composed of large, polygonal cells with typical oncocytic appearance. The tumor cells are arranged in follicles, trabeculae and solid areas. The nuclei are oval and round with prominent nucleoli. The mitotic index is quite low (<4 mitoses/10 Hpf). Focally, the tumor cells contained intranuclear hyaline inclusions. The tumor infiltrated the adjacent bone structures.  
Immunohistochemistry: CD56 (-), CD138 (-/+), Chromogranin (-), Synaptophtysin (+/-), Cytokeratin AE1-AE3 (+/-), IgG (+), Plasma cell (+).  
The patient has Bence-Jones proteins in her urine. (related to tumor?)  
Differential diagnosis: plasmacytoma, oncocytic carcinoma or pituitary adenoma?  
 
imported on 2006-11-25 13:06:14 originally owned by semir