Peripheral primitive neuroectodermal tumors. A flow cytometric analysis with immunohistochemical and ultrastructural observations.

Flow cytometry of classical neuroblastoma has provided provocative evidence that cell cycle and ploidy analysis generate prognostically useful information. To determine whether such analyses of peripheral primitive neuroectodermal tumors might yield similar results, formalin-fixed, paraffin-embedded tissue specimens from 19 peripheral primitive neuroectodermal tumors, each previously characterized by immunohistochemical or ultrastructural study, were assessed. An acceptable histogram was obtained in 16 cases. Of these, nine neoplasms were diploid and seven contained aneuploid DNA. Among patients with diploid lesions, four were free of disease, whereas three had persistent or recurrent disease, and two had died of tumor. Among patients with aneuploid neoplasms, four were free of disease, one had recurrence, and two had died. There was no apparent correlation between immunophenotype and proliferative activity with the clinical outcome. Among aneuploid peripheral primitive neuroectodermal tumors, DNA index did not predict survival. Hence, cell cycle and DNA ploidy analyses do not appear to contribute to the prognostic assessment of peripheral primitive neuroectodermal tumors, as they do to presumably related neoplasms of the central and peripheral nervous system.