Hyperhaploid uterine mesenchymal tumors—a novel genetic subgroup?

Hyperhaploid karyotypes have been described to occur in subsets of various solid tumors and leukemias. In these cases, monosomy is noted for most of the chromosomes while a few chromosomes still remain disomic. Evidence has emerged that at least in some tumor entities these remaining chromosomes are non-randomly selected. In addition, structural alterations can accompany the reduced chromosome number and secondary duplication of the chromosome complement is also a frequent finding. In this report, we describe hyperhaploidy in a case of an endometrial stromal nodule of a 50 year old woman who underwent hysterectomy because of symptomatic uterine fibroids. In addition, we review two other recently described cases of uterine mesenchymal tumors with that type of genetic alteration. Despite some histologic differences, striking similarities between these three cases exist with respect to the chromosomes were retained as disomic. Thus, the question arises if hyperhaploidy defines a novel genetic subgroup of uterine mesenchymal tumors.