ABSTRACT
The patient-derived tumor xenografts (PDX) model is an animal model established by directly engrafting fresh tumor tissue of patients into immunodeficiency mice after surgery or biopsy, which plays an important role in the study of tumor biology. However, the transformation of PDX into lymphoma limits the application of this model. The characters of this transformation include that epithelial tumors origin, predorminance of B-cell lymphomas, lost of architectural feature of primary tumor, absence of epithelial tumor markers, and CD45 and CD20 expression. That were characteristics of human B lymphocytes, and possible infection of Epstein-Barr virus(EBV). The biology of primary tumor, EBV infection, inflammation infiltration in primary tumors and the host immune status are the main related factors in this transformation. Therefore, selective xenograft by the detection of EBV infection and inflammation infiltration in primary tumors may be effective methods to prevent lymphomagenesis.