Presence or absence of trisomy 11 is correlated with histologic subtype in congenital mesoblastic nephroma.

Fluorescence in situ hybridization utilizing a probe for the alpha satellite repeat sequence on chromosome 11 was used to detect variations in the number of chromosomes 11 in 24 formalin-fixed, paraffin-embedded congenital mesoblastic nephromas. Evidence of trisomy 11 was found in nearly half of the tumors. More importantly, the presence of trisomy 11 was associated with the cellular histologic variant of this tumor.

Ovarian germ cell tumor evolving to myelodysplasia.

We present the case of a 14-year-old girl in whom a myelodysplastic syndrome was diagnosed 9 months after surgical resection and chemotherapy for an ovarian germ cell tumor. Cells from her marrow were characterized by trisomy 8 and an isochromosome 12p, a marker that appears to be unique to germ cell tumors. The presence of the same two anomalies in her original tumor was demonstrated by fluorescence in situ hybridization study of interphase cells in paraffin-embedded tissues and thus provided strong evidence that the two neoplasms had a common clonal origin.