DEVELOPMENT OF ENDOMETRIOSIS FROM EMBRYONIC DUCT REMNANTS

Among 18 cases of endometriosis involving ovaries and fallopian tubes, we identified three cases with foci of endometriosis adjacent to the embryonic duct remnants in the fallopian tube. The serial sections of the blocks of tissue containing areas of interest showed segments of e mbryonic duct remnants with changes suggestive of gradual transformati on to endometrial glands. The early changes consisted of replacement o f the muscular coat surrounding the epithelium of embryonic duct remna nts by the endometrial stroma with positive immunoreactivities for est rogen receptor. Subsequently there were changes of the embryonic duct remnant epithelium into endometrial epithelium with diffuse immunoreac tivities for estrogen receptor. The significance of this transformatio n as a mechanism of develop ment of endometriosis is discussed. Copyri ght (C) 1998 by W.B. Saunders Company.