Immunocytochemical detection of insulin-like growth factor II (IGF-II) in choroid plexus papilloma: a possible marker for differential diagnosis

Background: Insulin-like growth factor Il (IGF-II) has been detected in the choroid plexus of animals by means of immunohistochemistry and in situ hyb ridization, and this factor is thought to play an important role in the cen tral nervous system (CNS). Little is known, however, about the presence and localization of this substance in the choroid plexus and in choroid plexus papilloma in humans. Materials and methods: 5 normal choroid plexus and 10 choroid plexus papillomas were examined for IGF-II by immunocytochemistry. IGF-II was not detected in normal human choroid plexus, whereas it was fou nd in choroid plexus papilloma. Furthermore, to assess the possibility that IGF-II could serve as an immunohistological marker of choroid plexus papil loma, we used the same technique to examine paraffin-embedded samples from various kinds of brain tumors. Results and conclusion: Our results suggest that IGF-II may be a useful marker for choroid plexus papilloma in differen tial diagnosis.