Comment by dillydogg
To help support the "retrograde menses is incomplete" discussion; I was involved in a case where a woman had a bone marrow transplant for her CML. She later developed "appendicitis" when but when the tissue sample came to the pathologist, the appendicitis was actually endometriosis. Even more, the endometriosis was XY karyotype, ie derived from the bone marrow transplant. We wrote up a case report.
NB - It is a known phenomena in bone marrow transplant recipients that the donor DNA can be taken up by host cells by unknown mechanisms, so it isn't a guarantee that the endometriosis was developed from the transplanted bone marrow.
It's one thing to know, in theory, that stem cells can end up in strange places after transplantation, but to see that play out in something as enigmatic as endometriosis really underlines how little we know about the underlying mechanisms.