Cytogenetical observations and hormone receptor expression in five extra-uterine leiomyomas

The chromosomes were studied by an in vitro technique in four parametrial and one gastric leiomyomas. The findings in parametrial myomas (the present four cases and one published earlier) differed from the observations in uterine cases by the absence of normal stemlines and the absence of 1p,6p and 7q changes. As has been shown earlier for intraocular melanomas, the location within an organ or organ system could be the explanation for the chromosomal differences. The scanty data for leiomyomas in the digestive tract (the present case and two in the literature) suggest evolutionary patterns different from those in myomas in the genital tract. The reasons for this are unknown but differences in hormonal sensitivity, as reflected by estrogen and progesterone receptor expression, might at least be a contributory factory.