Duke Researchers 'Rediscover' a Female Reproductive Structure That Vanished From Textbooks a Century Ago

A structure on the female ovary that disappeared from modern medical textbooks is getting a second look, and the reason it vanished in the first place is now driving a fight on social media.

The rete ovarii was first described by anatomist Wilhelm Waldeyer in 1870, according to a paper from Duke University Medical Center researchers Dilara Anbarci, Jennifer McKey, Daniel Levic, Michel Bagnat and Blanche Capel. It appeared in early editions of Gray's Anatomy, the reference text generations of doctors trained on. Over time it dropped out of newer editions and got labeled a "functionless vestige," a characterization the Duke team traces to a 2021 paper by researcher Girsh.

What the Structure Actually Does

The Duke team's 2024 paper, titled "Rediscovering the Rete Ovarii: a secreting auxiliary structure to the ovary," describes a horseshoe-shaped tissue with three regions, the intraovarian rete, the extraovarian rete and the connecting rete, that persist from birth through adulthood.

According to reporting by Science News, developmental biologist Jennifer McKey first noticed the structure while imaging whole mouse ovaries at Duke and traced it back through old literature to the long-forgotten rete ovarii.

When researchers injected fluid into the extraovarian portion, it flowed toward the ovary, according to the paper. They also found the structure's cells sit close to blood vessels feeding the ovaries, receive direct nerve connections, and cluster near macrophages, the immune cells that help protect tissue. The cells carry receptors for estrogen and progesterone, and they release proteins tied to egg maturation and follicle maintenance whose activity rises as estrogen levels climb.

Co-author Dilara Anbarci told Science News the findings could help explain how the structure contributes to fertility and ovarian health. "There's still so much we can't even begin to comprehend about female anatomy," Anbarci said, adding she hopes the work "encourages more investigation in reevaluating what we don't already know about the ovary."

The rete ovarii isn't unique to humans. The Duke paper notes it shows up across guinea pigs, cows, sheep, swine, camels, dogs and monkeys. Evolution tends not to preserve useless tissue, a signal scientists generally treat as indicating a structure is doing real biological work.

The Viral Claim, and What the Research Actually Supports

An Instagram account called Hear Her Stories turned the story into a broader accusation. "Men deleted an organ from medical textbooks because they decided it was useless," the post reads, going on to ask, "Do men really hate women that much?" Comedian Michelle Wolf called the news "infuriating," according to the New York Post.

Women have a legitimate complaint that female-specific anatomy and conditions have historically drawn less research funding and attention than male-equivalent structures. The newsletter fiercebymitú makes that case directly, noting the rete ovarii's male counterpart, the rete testis, got studied, named and explained while the female structure "got a paragraph and then got cut."

Neither the Duke paper nor the researchers quoted in Science News claim the structure was erased out of malice toward women. The record shows a century of scientific disagreement and neglect, not a documented decision by any named individual or institution to suppress the finding. No source in this reporting identifies who removed the rete ovarii from later textbook editions or why, let alone establishes intent to harm women. The claim that "men hate women" is an interpretation added by a social media account, not a conclusion drawn by the scientists who did the work.

What the research establishes: a real structure got dismissed as useless without adequate study, and updated tools eventually proved that dismissal wrong. That's a knock on 20th-century research priorities and textbook editing decisions. It's not evidence of a coordinated plot.

What's Next

The Duke team's findings so far come from mouse models. Anbarci and her colleagues have not yet published data confirming the same fluid flow and hormone signaling occurs identically in human ovaries, meaning the fertility and ovarian-health implications for women remain a hypothesis under active investigation rather than a settled clinical finding. Whether the rete ovarii turns out to matter for treating infertility or ovarian disease in humans depends on research that hasn't been done yet.