Original articleExpression of SOX11, PAX5, TTF-1 and ISL-1 in medulloblastoma

The aim of our study was to evaluate the immunohistochemical expression of SOX11, PAX5, TTF-1 and ISL-1 in medulloblastoma (MB) to investigate their diagnostic usefulness.MethodsImmunohistochemical expression of PAX5 (two antibodies: Dako, DAK-Pax5; and BD, clone 24), TTF-1 (Dako, 8G7G3/1), SOX11 (CL0142; Abcam) and ISL-1 (1 H9, Abcam) was analyzed using the h-score and Remmele score in 25 cases of MB.ResultsThere were 18 MBs of classic and 7 of desmoplastic type. SOX11 was strongly expressed in all tumors. The expression of PAX5 was higher and more frequent in a case of DAK-Pax5 clone (25/25) than clone 24 (6/25). ISL-1 was positive in 11 (44%) and TTF-1 in 3 (12%) cases. ISL-1 expression correlated positively (p < 0.001), while TTF-1 correlated negatively with the age of patients (p = 0.039). PAX5 expression correlated with ISL-1 (p = 0.039) and showed a trend toward higher expression in the desmoplastic subtype (p = 0.069).ConclusionsSOX11 is strongly and robustly expressed in MBs. PAX5 expression pattern differs substantially among two antibody clones. TTF-1 and ISL-1 is associated with the age of patients.