Introduction

On July 7, 2020, the world of Surgical Pathology lost one of the brightest minds ever: Prof. Juan Rosai.

It certainly happened to many of us while approaching a difficult case to exclaim: “this is a case for Juan Rosai!” This simple expression synthesizes the legend that was created around him.

Those who knew him personally were undoubtedly amazed by his diagnostic insight, exceptional memory and organizational skills.

However, his vast culture and passions were not limited to medicine, but ranged to music, literature and the world of sports, especially football.

We worked with him in his last years of activity and want to share with the communities of pathologists our warm feelings about this exceptional pathologist and this profound person.

Memory of a gentlemen

While living in Milan, during the morning I used to work in Mario Colombo’s Molecular Immunology Lab, at the National Cancer Institute. Early in the afternoon, my trip to Inganni (Milan’s underground station near Juan’s Lab) was always punctuated by questions: “Will I ever be able to say something correct and useful about the cases that Juan is going to discuss with us?”; “How did he manage to classify those cells without even immunophenotyping them?”; “How many pieces of information conveyed by H&E-based morphology am I still completely missing?”.

On my first day at the multi-headed microscope, Juan introduced me as “one among the top hematopathologists… in the room”. That day we were four, I immediately loved his sarcasm. During our rides in the underground and along our tour of Sicily with Maria Luisa and Jerónimo Forteza we talked about so many things including football, literature, opera, Pirandello, Winston Churchill’s famous quotes, and occasionally pathology. I was far less than competent in most of the topics, but we had great conversations. Soon I realized that Juan was contributing most of the knowledge to our talks and that he never underlined the abysmal gap of notions and expertise between us.

He was a gentleman, a unique repository of talent, intuition and knowledge, and the most brilliant pathologist I have ever met. His kindness was deep enough to cope with my endless attempts to meticulously describe the research projects on which I was working at that time, which were consistently characterized by a conspicuous dyscrasia between the barely perceptible potential impact of the hypothetical findings and the extremely heavy burden of the required experimental plan. Among those projects were the potential re-induction of recombinase activity in tumor-infiltrating T cells as a mechanism induced by the peculiar antigenic milieu of tumors ¹, and the hypothesis of an MHC-engaged immune function of splenic sinusoidal endothelial cells (still on the high seas). Juan’s comments were able to pick the very essence of the experimental issue and his suggestions, always based on some kind of previous evidence to me apparently unrelated, opened new unexpected and sound hypotheses.

In these days, the dawn of expert systems based on neural networks or different computational architectures that fall under the umbrella of Artificial Intelligence applied to digital pathology is enabling an unprecedented level of insight into the integrated analysis of morphological clues derived from our beloved H&E-stained slides. These approaches reveal that morphology embodies an invaluable synthesis of the countless entwined and highly redundant variables relative to genetic and epigenetic landscapes, to mechanobiology and to microenvironmental interactions that shape cell and tissue fates. Such a perfect synthesis needs no awareness of its multifarious determinants and can occur naturally, as in the case of Juan’s great mind training in the best possible fashion, within the most challenging setting. Juan will always be the best possible synthesis of that constellation of things that we call Pathology.

See you, my dear friend.

Claudio

Life lessons

After more than one year since Prof. Rosai death it’s still difficult for me to remember him. His lost evokes in me conflicting feelings: on one side the sorrow of losing a person whom I was fond of and on the other side being aware of the privilege to have known and had been collaborating with him for 15 years.

His scientific production and his diagnostic value are unquestionable and known to everyone and it will also be to the new generations of pathologists. The contributions reported in the next pages, written by colleagues who deeply esteemed him, represent a tribute to just a small part of his scientific activity. Fortunately, his works and publications will enrich our profession forever.

Much of this heritage is accessible to everybody. This is also thanks to his intuition in understanding the potential of digital pathology which he used both for his consultations, becoming a pioneer in telepathology, and for educational and scientific purposes by deciding to digitalize most of the cases he collected during his career. The International Journal of Surgical Pathology, whose Editor in Chief had been Prof. Rosai for years, was the first to include in the online case report version the link to the digital slide of the described case.

“Describing” Prof. Rosai would have been impossible maybe even for Prof. Rosai himself, so in the following few lines I tried to remember him in the simplest way just as wonderful he was by telling some short and personal anecdotes about the time I had the fortune to spend with him. Just few simple memories that helped me growing.

A SECOND CHANCE

I met Prof. Rosai for the first time about 15 years ago. During the last year of my Pathology residency, I was allowed to attend for 6 months the facility directed by Prof. Rosai whom I considered a sort of abstract entity, a myth that I had never met in person.

From the very first days the experience was exceptional from any point of view: this Pathology Giant not only really existed, but he was also a person willing to spend part of his precious time by sharing and teaching his knowledge. I remember him like it was yesterday at the multi-headed microscope when he stood up while he was looking at a “unique” case to extract from his archives a similar case seen 30 years earlier during a seminar or in a consultation, or citing the most pertinent bibliographic reference carved in his memory.

In the same studio, hanging on an anonymous column, there was an A4 sheet containing a numbered list of ongoing projects, often involving what he perceived to be new diagnostic entities (about 36 projects). To each project were dedicated one or more binders identified with the same number of the list and in which were put together the preparations collected during his career.

This was only the beginning cause over the months my admiration for him increased day by day.

One day unfortunately I made a serious mistake that thanks to the numerous and punctual cross-checks made by Prof. Rosai it had no consequences for the patient. At the beginning it was thought that the responsible for this error was another person, but as soon as I realized I was the culprit I went to his office to inform him. The next day, under the multi-head microscope, I promised that I will have done everything possible to prevent this from happening twice. He replied, “Don’t worry, just in case, there won’t be a third time.” He laughed (only him).

A few evenings later he summoned me at his office, it was about 5 pm, I remember it very well because I was really worried about that unusual summon: he offered me a job. I understood only some years later why he had given me that second chance and that opportunity: he confessed to me that during his surgical internship he had also ignored his boss’ requests too in order to watch his soccer team in the championship final and in that occasion he had also received a second chance.

A PROMISE WAS A PROMISE

He was a person of unique moral integrity therefore a given word was worthy more than anything else.

One day he proposed me to participate with him in a project aimed to a publication. Clearly, I didn’t miss the opportunity to review cases with him.

The project was completed and the work sent to the Journal. The article was accepted and in a few days the abstract was available on PubMed. We were many authors and someone forgot to insert my name and he noticed it. I explained to Prof. Rosai that I didn’t care. He didn’t tell me anything. In the following days, I discovered he wrote to journal Editor in Chief and each single author and my name was added to the paper. This was him: a promise was a promise.

AN UNFULFILLED REQUEST

We always called each other by surname and it seemed natural to me.

A few months before he stopped his diagnostic activity, while we were at the microscope, he told me that we knew each other for more than 10 years and that was time to become more informal and calling by name. I was never able to accommodate him.

Bye Juan, rest in peace.

Giovanni

References

1. Morello G, Cancila V, La Rosa M. T cells expressing receptor recombination/revision machinery are detected in the tumor microenvironment and expanded in genomically over-unstable models. Cancer Immunol Res. 2021; 9:825-837. DOI