Isochromosome 11q in a case of Ewing's sarcoma

A low passage Ewing's sarcoma cell line established from a metastatic lesion was cytogenetically analyzed. The modal karyotype was 44,X, -8,i(11q), -15, +12. Other cells had random chromosome aneuploidy superimposed on this karyotype. No cell had a structural rearrangement involving 11q24 or 22q12 as described in other patients with Ewing's sarcoma, but all cells had an isochromosome 11q.