Louis “Pepper” Dehner, MD, never found out why his father started calling him “Pepper.”

“I have been ‘Pepper’ since the dawn of my existence,” he says. “I’ve always thought that — given the fact that my dad was an athlete and followed baseball and basketball very closely — my namesake might have been ‘Pepper’ Martin from the St. Louis Cardinals’ Gashouse Gang.”

Dehner never asked, and his father kept the reason secret to the end of his life. But the mystery hasn’t created any ambiguity in Dehner’s attitude toward his nickname.

“When someone calls me ‘Louis,’ I can only assume that either they don’t know me or they don’t want to know me,” the self-described “contrarian” says with a smile and a chuckle. “The only people who ever had difficulty calling me ‘Pepper’ were the sisters who taught at the Catholic grade school I went to. I guess that was because there’s no ‘St. Pepper,’ and you had to have a saint’s name.”

Dehner was born in 1940 in St. Louis Maternity Hospital, “probably just a few hundred yards from where we’re sitting,” he notes in his office at the Medical Campus. He grew up in East St. Louis. His father, a two-time basketball All-American at the University of Illinois, was the basketball coach at East St. Louis High School for 35 years. His mother was a junior-high English teacher.

“Both mom and dad were avid readers, and I grew up in this world that was defined in part by nonstop athletics, but also by immersion in a world of books,” he says.

Dehner had known since grade school that he wanted to become either a Catholic priest or a doctor. When he met and later married his high-school sweetheart, the choice was made: He would become a doctor.

Remembering good influences

When he reminisces, Dehner frequently shifts the focus from himself to the people and places that he feels have positively affected his life.

Dehner remembers undergraduate classes at Washington University with Victor Hamburger, PhD, the head of zoology, and Florence Moog, PhD, professor of zoology and a developmental biologist, as particularly influential. He did his senior project with Rita Levi-Montalcini , MD, professor of zoology and the future Nobel laureate in medicine and physiology.

“That really speaks to the environment at this university, that an undergraduate could not only just sit in their classrooms and be lectured by these individuals, but also work in their laboratories,” he says. “I have come to really appreciate the influence they had on me.”

At Washington University School of Medicine, Dehner’s contrarian streak led him to ignore the director of surgical pathology’s prohibition against first-year residents’ attendance at his morning conferences. The director, Lauren V. Ackerman, MD, protested the violation to the department head.

Dehner’s defiance was prompted in part by the knowledge that he likely was headed to Vietnam soon to honor a commitment to serve in the U.S. Navy. When Ackerman learned Dehner had been summoned to active duty, he called Dehner to his office to express his regret at the news and to offer him a fellowship in surgical pathology when he completed his service.

“Dr. Ackerman didn’t know a lot about me other than my showing up at his morning conferences,” Dehner says. “But he was enough of a student of human nature to know that some hope was necessary in everybody’s life, and he provided me with that at a critical time.”

Helping surgeons know their enemy

When he returned from Vietnam and service at the Armed Forces Institute of Pathology in Washington, D.C., Dehner set out to make himself into a pediatric surgical pathologist with the aid of pediatric pathologist John Kissane, MD.

“Dr. Dehner remains as enthusiastic about pathology as a discipline today as he was when he was a student at the School of Medicine,” says Kissane, 82, partially retired professor of pathology and immunology. “His unflagging interest in the field has never subsided, and that’s what makes him both a great scientist and a great teacher.”

Surgical pathologists work with oncologists and surgeons to identify the type of tumor a patient has and determine the best plan for treatment. Pediatric surgical pathology was just getting started at the time Dehner entered the field.

“The difference between adult and pediatric surgical pathology is that children get different diseases,” Dehner says. “Tumors in children are entirely different in terms of their pathology, how they look, how they behave and how they respond to treatment.”

Inspired by Kissane, who wrote an important book on pediatric pathology, Dehner put together the first book on pediatric surgical pathology. It was published in 1975; a third edition currently is in the works.

In 1977, Dehner was the first to identify and characterize a type of tumor known as pleuropulmonary blastoma. Dehner and colleagues like Jack Priest, MD, an oncologist at the Minneapolis Children’s Hospital and Clinics, have spent years developing diagnosis and treatment strategies that have helped save the lives of many children with the condition.

In spring 2009, Dehner received the Distinguished Pathologist Award of the United States & Canadian Academy of Pathology (USCAP) at the academy’s annual meeting. The award is the field’s highest honor.

In summer 2009, a former student and colleague of Dehner’s, Ashley Hill, MD, now chief of pathology at the Children’s National Medical Center, brought his work full circle by identifying the first gene linked to pleuropulmonary blastoma.

“Pepper Dehner is one of those once-in-decades figures who influences everyone around him in positive ways,” says Skip Virgin, MD, PhD, the Edward Mallinckrodt Professor and head of Pathology and Immunology. “Our department would not be nearly as strong and influential as it is without Pepper’s strength, vision, loyalty and hard work.”

Dehner says he has no plans for retirement.

“I show up at work every day to see something that I have never seen before, and that continues right up to this day,” Dehner says of his field of study. “What I have learned about pathology is that, in some respects, it’s a deep well without a bottom.”

Fast facts about Louis “Pepper” Dehner

Born: Oct. 2, 1940
Family: Wife, Becky; sons Louis Jr., 49, Carl, 48, and Christopher, 47; daughters Elizabeth Ann, 42, Rebecca Miriam, 21, and Rachael Sara, 16
Hobbies include: Reading about the Civil War and visiting historic battle sites. Dehner has his great-grandfather’s Appomattox parole framed and hanging on a wall.
Exercise: Dehner, a former marathon runner, now runs five miles “most days.”