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Juan Rosai, MD, a Pioneer in Pathology, Dies at 79

July 14, 2020

Juan Rosai, MD, a former Department of Pathology faculty member, passed away in Milan, Italy, on July 7, 2020, after a long illness. During his time at Yale, he had a major impact on the culture of the department. To those who had the honor to train under him, he was an outstanding mentor.

Rosai was born in Italy in 1940. When he was 8, he immigrated with his family to Argentina where he went to medical school at the age of 15 and did a residency in anatomic pathology. On invitation from Dr. Lauren Ackerman, he came to the United States and did another pathology residency and fellowship at Washington University in St. Louis, subsequently joining its faculty. He was appointed professor and director of anatomic pathology at the University of Minnesota in 1974, when he was only 34. While on sabbatical in Italy in 1983, he met his future wife, Dr. Maria Luisa Carcangiu, also a pathologist, and they quickly became inseparable companions and collaborators. Together, they were responsible for laying the groundwork for the modern classification of thyroid cancer. In 1985, he joined Yale as the director of anatomic pathology, his wife becoming the local expert in gyn pathology. He left a short six years later to become the chair of pathology at Memorial Sloan-Kettering Cancer Center in New York. After eight years there, he returned home to Italy, where he remained diagnostically active for many years.

Rosai is known for identifying and characterizing a number of diseases spanning the entire body. But perhaps his greatest contribution has been to bring emerging thought and technologies into the mainstream practice of pathology. He was an early adopter of immunohistochemistry, synoptic reporting, molecular diagnostics, and even digital pathology. His knowledge of pathology was encyclopedic, and his textbook on surgical pathology is considered by many as “the” textbook in the field; it has been translated into more than half a dozen languages.

Rosai has been described by peers as “an icon in the field,” “one of the greatest surgical pathologists ever,” “a true leader and inspiration,” and a “paragon and fundamental creator of precision in surgical pathology.” He was the reason why many pathologists say they chose that discipline. But beyond his incredible diagnostic abilities, he was considered a true gentleman, and he engendered the utmost respect and admiration from an entire specialty of medicine and beyond. Even for those privileged to get to know him well enough that he asked to call him by his first name, somehow “Dr. Rosai” always seemed more appropriate.

Despite his relatively short time at Yale, Rosai had a major impact on the culture of the department. To those who had the honor to get to train under him, he was a mentor in the greatest sense of the word: he made them want to be the best pathologists we could be, and they knew he would be there if they ever needed help. Educating future generations of pathologists was his true passion. He spent time one-on-one with all his trainees. Every case was an opportunity to teach. And that continued long after one was no longer a trainee. If you trained under him, you were entitled to free lifetime consultations. Always humble enough to admit his rare mistakes, he used them as teaching examples for everyone else.

The impact Rosai has had on the field of pathology cannot be overstated. He changed the entire discipline, and his trainees populate pathology leadership positions around the world. He is survived by his beloved wife, Dr. Maria Luisa Carcangiu, his three sons (Alberto, Carlos, and John), and his four grandchildren.

Submitted by Robert Forman on July 14, 2020