I pull up a test result for my patient, and the senior resident standing behind me lets out an excited squeal.

“I’ve never seen the imaging come back positive for this,” she says.  Our two-week-old infant, who already has a rare infection, also has a rare associated structural abnormality.  It’s not benign, but it is fixable.  The fix usually requires surgery.

As we walk over to the patient’s room to update her mother, my senior gushes about the zebra that was uncovered on the ultrasound.  She asks me if I’m excited.   “I dunno,” I mutter, which is somewhat more diplomatic than my discomfort that she is.  ”Her kid has to get surgery now.”

But in the room, the resident says all the right things to the patient’s mother, with the right amount of explanation, reassurance, clarity, and tone.  She shuts the door and looks at me, finally, in sad contemplation.  ”Let’s give her a bit.  I think she’s going to cry now.”

Since I work at a well-known teaching hospital, we get referred many cases you only hear about in textbooks.  Perhaps I’ve gotten spoiled: on my first day I picked up a teenage patient with a chronic disease with an incidence of 1 in 200,000.  Yet it wasn’t until my third week that I saw my first child with asthma–a condition that is 20,000 times more common.  A resident with four years of practice, meanwhile, has treated thousands of asthmatics, thousands of stomach viruses, and thousands of strep throats.  Seeing something for the first time in years must trigger that flurry of novelty that I still get on a nearly daily basis.

This rationalization does nothing to quell my unease that a doctor’s initial reaction to an unusual and undesirable test result was happiness.

Excitement about anomalies crops up in different ways.  Recently, a resident reported being “obsessed” with a patient’s cough.  He took a thorough history and physical exam, scoured the literature, wracked his brain.  He wanted the cough to be tuberculosis.  He tried to make the pieces fit the diagnosis, but they weren’t quite the right shape.

Why the desire for the cough to be more than just a cough?  Cinching an esoteric diagnosis is fulfilling.  If it is a dangerous but treatable disease like tuberculosis, then I imagine it is even more fulfilling.  In this case, perhaps obsession drives better patient care.  In fact, there is a school of thought that the best doctors are the most curious ones, and I don’t disagree.

But the conflict remains.  Do we wish an interesting tragedy on a patient over no tragedy at all?

“To be a doctor you have to be aroused by sickness,” my classmate told me.  I felt the unease creep up again.  ”I’m aroused by making sick people better, not by the sicknesses themselves,” I shot back, sounding a bit more confident than I felt.

My 1-in-200,000 patient had infected lungs.  With what, we weren’t sure.  We took his chest x-ray to a radiologist.  The diagnosis was inconclusive.  ”It’s an interesting case,” the radiologist said, looking thoughtful.  I thought about the interesting lungs belonging to the interesting patient.  He was upstairs playing Wii, unaware of just how darn interesting he was.

Can I simultaneously be fascinated by sickness and also wish it didn’t exist?

On one of my first days on surgery, I was stitching up a patient’s abdomen when I felt a sharp twinge in my finger.  I peeled off my gloves and saw a drop of blood that wasn’t the patient’s.   I uttered a few choice words under my breath, scrubbed my hands like Lady Macbeth, and went to the emergency room.

The chances of someone having HIV are 1 in 200.  The chances of contracting HIV via a needlestick are 1 in 300.  As of today, there is not a single documented case of HIV transmission using the particular needle I did.  If I get it, I would be really interesting.

I wonder if somewhere out there a doctor’s subconscious is rooting for the zebra that could kill me.

Note: Minor patient details have been changed to preserve anonymity.

Shara Yurkiewicz is a medical student who blogs at This May Hurt a Bit.