Immunophenotype profile of childhood medulloblastomas and supratentorial primitive neuroectodermal tumors using 16 monoclonal antibodies.

Immunophenotype analysis of 17 childhood medulloblastoma (MED) and supratentorial primitive neuroectodermal tumors (SPNET) was performed on frozen sections using 16 monoclonal antibodies (MoAb) with the biotin-streptavidin alkaline phosphatase immunohistochemical technique. Neuroectodermal associated antigens, reacting with MoAb UJ13/A, UJ127.11, UJ167.11, and UJ223.8 were detected on greater than 10% of the cells in 15 of 17 MED/SPNET. Thy-1 was present on 14 of 17 tumors and absent on two of three SPNET. Neuronal (NF) and glial (GFAP) differentiation markers were evaluated. NF-H was demonstrated in 15 of 17, NF-M in six of 17 and NF-L in one of 17 tumors; GFAP was positive in nine of 17 patients. In nine of 17 MED/SPNET both proteins were present within the same tumor. Common leukocyte antigen was demonstrated on greater than 50% of the cells in four of 14 tumors as were shared tumor/leukocyte markers using monoclonal antibodies Thy-1, PI153/3, UJ308. The most frequent MED immunophenotype analysis was UJ 13/A+, UJ 127.11+, UJ 167.11+, UJ223.8+, PI 153/3+, A2B5+, GFAP+, NF-H+, and CLA-, NF-M-, NF-L-, 215-, 275-, 282.1-. The authors conclude that MED and SPNET are heterogeneous for expression of 16 markers and have similar immunophenotype analysis profiles, supporting the concept of their common, neuroectodermal origin. Common leukocyte antigen on both tumor cells and leukocytes precludes identification of tumor infiltrating leukocytes using monostaining techniques.