Department of Biomedical Sciences and Human Oncology, University of Turin, Turin, Italy.
Extremely rare cases of paraneoplastic syndromes or ectopic production of proteins associated with liposarcoma are reported in literature. We describe a unique case of relapsing retroperitoneal dedifferentiated liposarcoma with biochemical, immunohistochemical, and molecular evidence of alpha-fetoprotein (AFP) ectopic production. The lesion was associated to elevated AFP plasma levels that subsided after tumor removal. Immunohistochemical studies showed AFP production by a minority of tumor cells and reverse transcriptase polymerase chain reaction confirmed AFP mRNA expression. Finding of MDM2 and CDK4 iperexpression by immunohistochemistry confirmed the diagnosis of dedifferentiated liposarcoma.