Genital Rhabdomyoma of the Lower Female Genital Tract: A Study of 12 Cases with Molecular Cytogenetic Findings

Of the subtypes of extracardiac rhabdomyoma, genital rhabdomyoma is most uncommon and is occasionally classified as fetal rhabdomyoma due to morphologic similarities. In contrast to other forms of rhabdomyoma, the genetic alterations of genital rhabdomyoma are unknown. The clinical and pathologic findings in 12 cases were reviewed and 2 cases were processed for whole genome copy number analysis by single nucleotide polymorphism microarray. Twelve patients ranged in age from 43 to 65 yr (mean: 50.2 yr). Nine tumors arose in the vagina and 3 in the cervix, with their greatest dimension spanning 0.9 to 1.7 cm (mean: 1.4 cm). Follow-up was available for 7 patients and none had evidence of recurrence (67-263 mo, mean: 153.7 mo). No somatic copy number alterations, particularly involving genes in Hedgehog signaling, were identified by microarray. Although genital rhabdomyoma has sufficiently unique clinicopathologic characteristics including age of onset and organs of involvement to distinguish it from fetal rhabdomyoma, the genetic mechanisms underlying its development are unclear given the lack of copy number variation and loss of heterozygosity by single nucleotide polymorphism microarray.