Development of the human Müllerian duct in the sexually undifferentiated stage

Abstract

An embryological explanation for the development of the Mü llerian duct still poses a major challenge. The development of this duct was investigated systematically in human embryos. Seven embryos (Carnegie stages 18 -23) were serially sectioned in the frontal, sagittal, and transversal planes at a thickness of 10 m and stained with hematoxylin and eosin (H&E) for histological analysis. In all observed embryos, the caudal end of the Mü llerian duct was found to be intimately connected to the Wolffian duct. The opening of the Mü llerian duct to the coelomic cavity was formed as the result of an invagination of the coelomic epithelium at Carnegie stage 18. The duct grew independently from the invagination during stages 19 -23. The fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23. This is the first description of the caudal portion of the fused Mü llerian ducts separating again and returning to each of the Wolffian ducts in human embryos. Anat Rec Part A 272A: 514 -519, 2003.

Impact of tubal ligation on routes of dissemination and overall survival in uterine serous carcinoma

“…Considering the common embryonic origin of the epithelium of the uterine cavity and fallopian tube [12], each of these sites potentially could be the primary origin of exfoliated cells or tissue fragments leading to intra-abdominal metastatic implants. The exfoliation of malignant endometrial epithelial cells, with retrograde passage via the fallopian tubes, is considered the most plausible route of tumor spread to the abdominal cavity [5,[13][14][15].…”

Regulation of Wolffian Duct Development

“…The MD forms in an anterior to posterior manner by invagination of the coelomic epithelium of the mesonephros, between E11.5 and E12.5 in mice [2], and between 6 and 7 weeks of gestation in humans [4]. The presence of the WD appears to be essential to induction of MD formation.…”

Normal and abnormal epithelial differentiation in the female reproductive tract

“…As the MDs grow caudally, they cross over the WDs and meet in the midline to fuse with each other (B′). The caudal tips of the MDs remain separated to keep contact with the WDs (Hashimoto, 2003). Right before the MD tips reach the urogenital sinus, they finally become united and fuse with the UGS.…”