In a series of studies, we have hypothesised that endometriotic proliferati
on is, in part, precipitated by mutations in oncogenes or deletions in tumo
r suppressor genes that have been shown to be important steps in the transf
ormation from a benign to a malignant epithelium. We reported previously th
at we could find no mutations in the TP53 and RASK genes in cases of endome
triosis. However, having shown that endometriotic deposits were monoclonal,
we showed loss of heterozygosity on chromosomes 9p (18%), 11q (18%), and 2
2q (15%)- in total 28% of endometriotic lesions showed loss of heterozygosi
ty at one or more sites [1]. We could not demonstrate any loss of heterozyg
osity in normal endometrium. We examined adjacent endometriosis, atypical e
ndometriosis, and endometrioid carcinoma of the ovary and showed common gen
etic alterations that are consistent with a common lineage, These common al
terations were not seen in lesions that were distant from each other [2]. I
n endometrioid tumors, we reported an increased frequency of mutations in t
he PTEN/MMAC tumor suppressor genes that was not seen in clear cell or sero
us carcinoma, suggesting distinct developmental pathways for these tumors [
3]. Copyright (C) 2000 S. Karger AG, Basel.