Immunoreactivity of CD10 and inhibin alpha in differentiating hemangioblastoma of central nervous system from metastatic clear cell renal cell carcinoma

The differential diagnosis between hemangioblastoma of the central nervous system and metastatic clear cell renal cell carcinoma can be problematic, because they may share striking morphologic similarities. Since CD10 is expressed in clear cell renal cell carcinoma, while inhibin alpha is expressed in hemangioblastoma, we used CD10 and inhibin alpha ( inhibin A) to study their possible use in the distinction of these two entities. A total of 22 cases of cerebellar hemangioblastoma, five cases of metastatic clear cell renal cell carcinoma to the central nervous system, and 16 primary cases of clear cell renal cell carcinoma were studied with immunohistochemical staining of both CD10 and inhibin A. All 22 cases of hemangioblastoma were immunonegative for CD10 in the stromal cells. In contrast, all five cases of metastatic clear cell renal cell carcinoma and 16 cases of primary clear cell renal cell carcinoma showed positive CD10 membranous staining. In all, 20 cases of hemangioblastoma (20/22, 91%) expressed inhibin A in the stromal cells. Two cases of primary clear cell renal cell carcinoma (2/16, 13%) and three cases of metastatic clear cell renal cell carcinoma (3/5, 60%) showed immunopositivity for inhibin A. In conclusion, in addition to the immunostaining of inhibin A, CD10 is a superior marker for distinguishing between a hemangioblastoma and a metastatic clear cell renal cell carcinoma.