Ask any practicing pathologist or upper level resident to describe their diagnostic criteria for any lesion and you'll get a verbal laundry list of features, just as one would find in any textbook description. What is an adenocarcinoma? It's a malignant tumor usually composed at least in part of glands, which are in turn circular arrays of polarized cells (more basal nuclei) around a central lumen. Ask about a squamous cell carcinoma and words like keratin, eosinophilic, pavement stone, pearls, cell attachments, dyskeratotic, and hyperchromatic will spout forth. And yet, this is most certainly NOT how we function when we're actually MAKING diagnoses. The reality is that the diagnostic process in surgical pathology is an inherently non-verbal, right brain, pattern recognition process that takes place extremely rapidly without our being fully aware of what's going on. We look at a slide and almost instantly the right side of our brain tells us that this is a squamous cell carcinoma. After that, at a much more leisurely pace our left brain confirms the diagnosis by ticking through at least a partial list of features that should be present: yes, the nuclei are pleomorphic and mitotically active; yes, there are keratin pearls; yes, there is an infiltrating growth pattern.
The initial diagnosis is reached blindingly fast and non-verbally by our right brain, but NEEDS to be confirmed by our rational left-brain side. Those who lack the right brain skills of pattern recognition are often said to lack the "eye" needed for surgical pathology. When given a slide they mentally wander aimlessly through lists of diagnostic criteria until, if they're lucky, they hit upon the proper answer, but they are seldom sure of themselves. Those who have excellent right brain diagnostic skills, ie. the "eye," but fail to subject their snap diagnosis to left-brain review are quite often correct, but set themselves up for the occasional VERY bad mistake.
The ability of the brain to make nearly instantaneous decisions based on visual, non-verbal cues is undoubtedly of great evolutionary value. Is the person running rapidly toward me angry, happy, friend, foe, dangerous, etc? An instantaneous reaction is required and there's not time for the left brain to search the laundry lists of facial features. Although we don't really understand what's going on in our right-brains and cannot verbalize what are at their core non-verbal phenonmena, a tremendous amount of our brain power is devoted to such "cue reading." It is the core of social interaction, as well as, among many other things, microscopic diagnosis.
, the "megasavant" who was the basis for Dustin Hoffman's character in Rain Man, had a number of severe CNS structural abnormalities including agenesis of the corpus callosum. The result was an individual with, in essence, a brain with two left sides. He had an unfathomable memory for anything he had ever read, seen or heard, but he could not read facial cues or react appropriately in simple social situations. He could have undoubtedly given the definitions, word for word, for any tumor from any text he had ever read, but he would have been helpless looking through a microscope.
If you're interested in how the right brain functions, and as a pathologist you probably should be, I strongly recommend the book, "Blink, The Power of Thinking without Thinking,"
by Malcolm Gladwell
. Mr. Gladwell is also the author of "Tipping Point."
"Blink" is a short and fascinating tour through the non-verbal world of the right brain. You'll learn when to trust it and when to question its decisions, good skills for a pathologist!