MONDAY, April 8, 2019 (HealthDay News) -- Before her recent passing at the ripe old age of 99, Rose Marie Bentley harbored a remarkable secret.
Outwardly, nothing seemed out of place or extraordinary about this longtime resident of Oregon's rural northwest.
Bentley and her husband had five children and ran a farm and pet supply store in the town of Molalla. She taught Sunday school and sang choir at their United Methodist Church. And despite arthritis and three surgeries, she was in good health throughout her long life, unburdened by chronic illness.
But after she died in 2017, researchers at Oregon Health & Science University (OHSU) discovered that Bentley was, in fact, an extraordinary individual -- 1 in 50 million, in fact -- due to a hidden anatomical rarity.
Her stomach, liver and other abdominal organs were switched in position right to left.
The cause of this organ reversal condition, called "situs inversus," remains unclear, though a genetic underpinning is suspected.
But study author Cam Walker and his team know the condition starts in the first month or so of a pregnancy, and can take several different forms.
"These range from partial to complete, affect some or all organs, and usually refers to the orientation of the heart," said Walker, an assistant professor at OHSU's Anatomical Services Center.
In most people the heart is located on the left side of the chest and points in a leftward direction. But in most situs inversus cases the heart is on the right side of the chest (thoracic cavity) and points rightward (dextrocardia). This condition, said Walker, affects roughly 1 out of every 10,000 people.
But Bentley had an even rarer configuration -- affecting about 1 in every 22,000 people -- in which her heart was located on the left and pointed left (levocardia), despite the fact that several of her other major organs were located in the mirror opposite position of where they should be. Levocardia patients typically struggle with very serious heart defects and heart disease, which Walker said can "drastically limit longevity."
This makes Bentley's story all the more remarkable.
"In fact, in a thorough search of the literature, I found only two persons who had lived into adulthood with the type of situs inversus seen in this donor," Walker added.
The two other patients lived only to their 70s, making Bentley the oldest such patient ever found and the case "as remote as 1 [out of] 50 million individuals," Walker said.
He and his colleagues presented their observations Monday in Orlando at a meeting of the American Association of Anatomists.
During her lifetime, Bentley underwent an appendectomy, and at the time "a surgeon did point out that her appendix was on the wrong side," Walker noted. But her heart and digestive tracts functioned normally, and "she was likely unaware of the full extent of variation in her thoracic and abdominal cavities," he said.
However, before she passed away on Oct. 11, 2017, Bentley and her husband, James (who had died 13 years earlier), had signed up for OHSU's "Body Donation Program."
As a result, "her unique anatomy was found during routine anatomy dissection classes for medical students," said Walker.
"My colleagues and I returned several times to help the students figure out what was going on in this donor," he recalled. "It was soon very clear we had a very special example of anatomical variation from which to instruct students."
Walker suggests the opportunity has yielded some equally rare insights. "From a student perspective," he said, "the discovery of anatomical variation like this leads to moments of discovery that highlight the importance of learning anatomy, and learning to appreciate and then solve the puzzle of anatomic variation that can then be used to effect patient care.
"She also served as a catalyst for discussions with students about empathy for the donor and a unique human condition," Walker added. "Also, in remembering to consider all their future patients as individuals, who need care tailored to them as individuals, as expressed here by unique anatomy."
And according to Bentley's daughter Louise Allee, "She would be tickled pink that she could teach something like this. She would probably get a big smile on her face, knowing that she was different, but made it through."
Dr. Nieca Goldberg is director of the NYU Center for Women's Health in New York City, and was not part of the study. She agreed with Walker that this particular instance of anatomical novelty serves as a nice illustration of the importance of "treating all patients as individuals."
And while acknowledging that the unusual case of Rose Marie Bentley "does appear to be the exception, rather than the rule," Goldberg cautioned that there is likely a lot about situs inversus that remains a mystery.
"We really don't see this sort of thing that often, for obvious reasons," Goldberg noted. "And that could mean that we don't really know if we have a true sense of how common, or not common, it really may be."
The U.S. National Center for Advancing Translational Sciences has more on situs inversus.