You can't stay pluripotent forever

The human body contains all kinds of cells: cells that secrete mucus, cells that sense light, cells that make up your skin, cells that make up your brain. But we begin as embryos, which are devoid of these "differentiated" types of cells. No matter how much you dig, you will not find in an early embryo the specialized cell that manufactures your stomach acid. Rather, embryos contain "pluripotent" cells. These remarkable cells, which multiply in number during development, can differentiate into progressively more specialized types of cells. Taken together, the pluripotent cells possess the unique ability to become any type of cell in the body.

Once a pluripotent cell differentiates, it cannot become pluripotent again. A taste bud can't become a sweat gland. Its job is ordained.

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As an undergraduate, I had a romantic image of myself as doctor. I had arrayed in my mind brief snapshots, as though from a movie, of myself (with grayed temples and long white coat) performing manifold deeds:

-counseling a newly pregnant woman on prenatal care
-uncovering a tricky diagnosis in an emergency room patient
-delivering a newborn child
-helping a teenager overcome an eating disorder
-tailoring a cancer treatment to a patient's genetic signature
-leading a community in the face of a frightening pandemic
-performing a circumcision
-treating patients in a refugee camp

Although a doctor's license technically allows him to practice any kind of medicine, what I had barely grasped was that a doctor's specialty largely dictates which diseases he does (or does not) treat. Internal medicine doctors don't deliver children. A spine surgeon will not medically manage a thyroid disorder. A pathologist doesn't see patients in outpatient clinic.

I used to think that to become "super-doctor," I needed to enter the medical specialty that offered the broadest scope of practice. The obvious choice was family medicine, which includes basic surgeries, childbirth, and treating patients of all ages. Family medicine physicians excel when working in sparsely-populated areas, where their broad set of skills proves especially valuable.

But recently I've begun valuing depth over breadth. When I shadow specialists, I find that within their specialty, they tend to outperform non-specialists. Pediatric hospitalists are particularly good at taking care of hospitalized pediatric patients. A knee surgeon is particularly good at operating on knees. An oncologist is particularly good at treating cancer. I feel I'd serve my patients best if I too focused on some segment of medicine that captures my particular interests and plays to my strengths.

It's hard to stomach that someday I will probably see either adult patients or pediatric patients, but not both. I entered medicine because I wanted to help all people, not just those with gastric cancer, or with cataracts, or who are under the age of 18.

Being a medical student is an exciting time. We study all disciplines of medicine. We perform mandatory clerkships in all of the core medical specialties. During fourth year, we can take electives in whatever field we want. But we cannot forever remain medical students. Eventually we have to choose a path, and leave behind options once open to us. I take solace in some sagely advice I once had received: "You can't stay pluripotent forever." For now, I intend to enjoy this time of limitless potential.