Terapia prechirurgica della fibromatosi uterina - FedOA - Università ...

The histological evaluation of leiomyoma pseudocapsule showed a less defined border between
myoma and myometrium in pre-treated cases. This could be a possible explanation for the fact that
surgeons did not promptly identify the correct cleavage plan between myoma and myometrium in the
majority of pre-treated patients.
Literature data about the effect of GnRH-a treatment on uterine leiomyoma cell proliferation are
conflicting. Routine histological examinations of leiomyomas have failed to demonstrate changes in
cell proliferation (13). On the other hand, some authors reported reduced expression of Ki67 antigen
and/or PCNA antigen (14,15), some others found significant over-expression of PCNA and significant
elevation of Ki67 after GnRH-a therapy (16). In a previous study (5), we found a reduction in PCNA
expression after GnRH-a treatment, but it did not reach levels of statistical significance in comparison
with untreated leiomyomas. In the present report, instead, we found a significant reduction in PCNA
expression in the peripheral areas of leiomyomas. But in this study we considered PCNA expression
only in the pseudocapsule and not in the whole leiomyoma.
A reduced tissular trophism due to the decreased cell proliferation in the peripheral areas of pre-
treated leiomyomas could be at least a partial explanation for the loss of the cleavage plan between
leiomyoma and surrounding myometrium.
As regards leiomyoma vascularization, a reduced CD34 expression after GnRH-a administration has
been reported in literature (8,9). In the present study, we underline that this reduced expression is
more evident in leiomyoma pseudocapsule. This observation, together with the decreased cell
proliferation, could account for the loss of cleavage plan between myometrium and leiomyoma.
Moreover, the reduced vascularization could contribute to explain the reduction of intraoperative
blood loss found during myomectomies performed after medical pre-treatment.
In conclusion, the present report proposes a relationship between some clinical and surgical findings
and the morphological and immunohistochemical changes of leiomyoma pseudocapsule after GnRH-a
pre-operative treatment. The observation of a reduced cell proliferation and vascularisation of the
102