ROUTINE KARYOTYPING IN WILMS-TUMOR

We describe the karyotypes of nine Wilms tumors (WT). Four tumors were initially karyotyped from diagnostic needle core biopsies, 3 after po stchemotherapy tumor resection and the remainder from xenografts grown in nude mice. The 9 nephroblastomas were composed of 7 with favorable histology (intermediate-grade malignancy) and 2 with unfavorable hist ology (anaplastic or high-grade malignancy). The 7 tumors with favorab le histology had karyotypes typical of WT, with the previously describ ed nonrandom abnormalities +1q, +6, +7, +8, +12, +13, +18 and structur al abnormalities of Ip and 16q present in at least 2 case. The most co mmon abnormalities were trisomy 18 (4 cases) and +1q (3 cases). The 2 tumors with unfavorable histology both herd complex karyotypes atypica l for WT. We suggest that cytogenetics can act as a marker when histol ogic grade is in doubt. Karyotypic analysis from needle core biopsies was attempted in 6 samples, including 1 from a nephrogenic rest (NR) o f the nonaffected kidney and provided a result on 5 occasions. The NR were present in the sole case with a constitutional abnormality, a mos aic partial duplication of 8q. However, both the tumor and the NR were apparently derived from the normal cell line. Here we demonstrate tha t a cytogenetic result can be routinely obtained from needle core biop sies and Mill thus facilitate true diagnostic tumor karyotypes in both WT and other tumors. (C) Elsevier Science Inc., 1997.