Ring (13)(p11q34) as the sole abnormality in a leiomyosarcoma of the small bowel.

Cytogenetic investigation of a recurrent leiomyosarcoma of the small bowel from a 45-year-old woman revealed a r(13)(p11q34) as the sole abnormality in a majority of the cells analyzed. In addition to one cell with a normal karyotype, five cells showed loss of chromosome 13, presumably the r(13) marker. The presence of the r(13) as the sole abnormality suggests that alteration of genes on this chromosome could have played a role in the pathogenesis of this tumor.