The expression pattern of endometrial receptivity genes is desynchronized between endometrium and matched endometriomas.

RESEARCH QUESTION: Are paired samples of endometrium and ovarian endometriomas synchronous with each other throughout the menstrual cycle?

DESIGN

The expression levels of 57 endometrial receptivity-associated genes were determined from matched endometrial and endometrioma samples (n=31) collected from women with endometriosis throughout the menstrual cycle.

RESULTS

The expression profile of endometrial receptivity genes divided endometrial samples according to their menstrual cycle phase. Endometrioma samples grouped together irrespective of the menstrual cycle phase and formed a cluster distinct from endometrial samples. Pairwise comparison showed 21, 16, 33 and 23 differentially expressed genes (adjusted P < 0.001-0.05) between the lesions and endometria collected in the proliferative, early-secretory, mid-secretory and late-secretory menstrual cycle phases, respectively, confirming the distinct expression profiles of endometrium and endometrioma.

CONCLUSIONS

No menstrual cycle synchronicity was found between matched eutopic and ectopic endometrium, suggesting that the concept of cycling endometrial tissue inside the endometrioma should be revised.