GLUT1 immunoreaction patterns reliably distinguish hemangioblastoma from metastatic renal cell carcinoma

Background: Hemangioblastoma and metastatic renal cell carcinoma (RCC) may show striking histologic similarities, and the distinction between these tw o tumors can be difficult. Both occur in middle age, and both occur with in creased incidence in von Hippel-Lindau disease (vHL). GLUT1 is an erythrocy te-type glucose transporter protein that is highly expressed by endothelia in brain - but not most peripheral - microvasculature, and by tumor cells i n many epithelial malignancies. GLUT1 is expressed by endothelial cells in juvenile hemangiomas, and endothelial GLUT1 expression has been reported fo r 2 hemangioblastomas arising in a single patient with vHL. Methods: We per formed immunoreactions for GLUT1 on archival hemangioblastomas from 12 pati ents tone with vHL), and on RCCs metastatic to brain of 9 patients. Results : Hemangioblastomas showed intense endothelial GLUT1 reactivity in 11/12 tu mors resections; the only GLUT1-negative tumor was one for which only previ ously frozen material was available for immunoreaction, and this tissue sho wed poor GLUT1 immunoreactivity of internal erythrocyte controls. Hemangiob lastoma stromal cell reactivity was found in only 1 case, and was weak and focal. RCCs, in contrast, showed no intralesional endothelial GLUT1 reactiv ity, but did show intense tumor cell membrane reactivity in 9/9 cases. Conc lusion: that GLUT1 immunoreactivity patterns reliably distinguish hemangiob lastoma from RCC.