Learning to see

ARTHUR was a retired philosophy professor in his 80s who came to my office three times a year for a checkup followed by a chat. In my examination room, I routinely listened to his chest, scanned his skin for irregularities, percussed his abdomen with my stiffened fingers and peered into his throat, shining a light and asking him to say, “Ah.” We had a relaxed rapport, which I believed would cause me to be especially careful with his healthcare. I was wrong.

One day he told me that he had had a sore on his gum for several months. He had never mentioned it, though he had shown it three months earlier to his dentist, who had told him not to worry. When it didn’t go away, the dentist reconsidered and sent Arthur to an oral pathologist. Now that I examined his gums, I wondered how I had failed to notice the lesion before.

The inch-long sore was pale, a whitish gray against the red background. Unfortunately, it told his future. The oral pathologist had performed a biopsy, which had shown the sore to be melanoma, and a CT scan revealed that it was already invading the bones of Arthur’s face.

He never blamed me and, until he died six months later, came to see me frequently, maintaining his cheeriness despite his pain. The oncologist assured me that a diagnosis a few months earlier wouldn’t have made a difference in terms of outcome, but still.... On one of Arthur’s final visits I said sadly, “I wish I had found it, Arthur,” and he replied evenly, “I wish I had shown it to you.”

After Arthur died, I found myself carefully scanning the gums of every patient. At the same time, I tried to be more formal with others than I had been with Arthur. I feared that being too friendly with a patient could keep me from searching deeply for bad diagnoses. Perhaps secretly, I thought, I didn’t want to find them.

Such diagnostic adjustments are common among physicians. Dr. Jerome Groopman, a professor of medicine at Harvard University and a staff writer for the New Yorker, writes about the various influences on a doctor’s decision-making in his new book, “How Doctors Think.” Groopman suggests that we are ruled by our expectations, which are formed from our experiences, both positive and negative. Because diagnostics involves a complex whirr of mental machinery, it can’t be completely objective -- and can sometimes lead doctors to mistakes as well as to an emotional investment.

Subjective thinking is not limited to the case at hand. A missed or delayed diagnosis can lead to overcompensation with future cases. During my medical training, one of my fellow residents undertreated an asthmatic by delaying treatment with steroids -- and the patient ended up in the ICU on a respirator. After that, she over-treated all her asthmatic patients and observed several in the ICU as a precaution. The rest of us felt that when it came to asthma, this resident had lost her perspective.

Now, after Arthur’s death, I worried that I would react similarly. Would my new obsession with gums upset the delicate balancing of factors that a good diagnostician requires? Would focusing on my patients’ mouths distract me from other crucial organs and subtle signs of illness?

I soon found out the answer -- and the lesson was greater than just the arbitrary boundary between dentistry and primary-care medicine.

My obsession with gums soon wore off, and in its place I found that I was performing a more thorough examination of the whole body and taking a more complete history. An overlooked diagnosis caused me to be more careful, to more fully understand that there is no part of the body and no potential illness that is off limits to me. I simply needed to throw a wider net to increase my diagnostic yield.

A few weeks after Arthur’s death, a woman in her late 50s came to see me with firm rubbery lymph nodes on the front and back of her neck. I immediately thought that lymphoma was the most likely possibility, but at the same time I noticed that her hair was very thick and dark for her age. I probably wouldn’t have noticed her hair at all pre-Arthur, since hair is not the usual stalking horse for an internist. But I was now alert to things out of the ordinary.

As I went through a complete “review of body systems,” I asked the patient about her hair. She remarked that it had just been dyed with a new technique that involved much scrubbing and that the swellings in her neck had occurred soon after.

This more innocent possibility -- hair dye allergy -- quickly eclipsed lymphoma as my lead theory. I ordered a CT scan of the neck rather than going straight to a biopsy, as I would have done if I had had no other explanation than cancer. We were relieved that the CT scan showed “reactive nodes” rather than suspicious-for-cancer nodes. Eventually, after the patient washed the dye out of her hair, the swellings in her neck began to shrink.

It was ironic how a missed diagnosis of cancer in one patient had led me to not prematurely considering cancer in another. More important, I was shocked back into a more carefully weighted world of diagnostics, where science, probability and informed intuition are my guides as opposed to heuristically hoping for the best -- or worrying about the worst.

Dr. Marc Siegel is an internist and an associate professor of medicine at New York University’s School of Medicine. He is also the author of “False Alarm: The Truth About the Epidemic of Fear.” He can be reached at marc@doctorsiegel.com.