ATYPICAL CYTOGENETIC ABERRATIONS IN 2 CHILDHOOD PERIPHERAL PRIMITIVE NEUROECTODERMAL TUMORS

Atypical cytogenetic abnormalities were detected in peripheral primiti ve neuroectodermal tumors (PPNET) of the extremity in two children. On e had an osseous tumor with a balanced reciprocal translocation, t(5;9 )(q22;q32), and had a complete response to therapy. The other had a no n-osseous tumor with an interstitial deletion, del(18)(q12.2q21.2), wa s resistant to combination therapy, and at autopsy had evidence of pos sible clonal evolution with the karyotype 46,XX der(8)t (8;8)(p11.2;q1 3), inv(16)(p13.2q12),del(18)(q12.2q21.2). Neither tumor demonstrated the t(11;22)(q24;q12) typically found in Ewing's sarcoma and PPNET, su ggesting heterogeneity of the cytogenetic aberrations seen in this rar e childhood malignancy. (C) 1995 Wiley-Liss, Inc.