Undifferentiated sarcoma of the liver in childhood: morphology, flow cytometry, and literature review.

Nine cases of undifferentiated sarcoma of the liver in childhood were investigated by conventional light microscopy, immunohistochemistry, and DNA flow cytometry. Different histologic patterns were discernible. In some cases, areas resembling poorly differentiated rhabdomyosarcoma were present. This histologic diversity was supported by the immunohistologic detection of desmin and cytokeratins in five cases. When evaluated by flow cytometry, four of five cases investigated were diploid; only one was aneuploid, and this patient had the most aggressive course. Follow-up investigations of our patients and those described in the literature revealed that the prognosis of this type of tumor is not as bad as is generally assumed. Of the patients reported in the literature with detailed follow-up information, 37.5% survived without evidence of disease for an average of 37.5 months, death occurred in 47.5% after an average of 11.9 months, and 15.0% were alive with disease.