He had abnormal blood counts, but no established diagnosis. He was anemic, requiring a blood transfusion every two months, just often enough to be a nuisance for anybody. His platelets were low, but not low enough to put him at risk for bleeding or to require platelet transfusions. And his white blood cell count was decreased, though again, not enough to render him prone to infections.

I had already pulled up his labs on the computer and had walked him through the results. Given his age and these laboratory values, it seemed likely that he had a condition called myelodysplastic syndromes, a group of cancers in which the bone marrow fails to make enough healthy blood cells.

The only way to be sure of the diagnosis was to perform a bone marrow biopsy. For that, we would have to stick a needle into the flat part of his pelvis, just below his spine, and remove a sample of marrow from deep within the bone, to be analyzed by a pathologist.

Bone marrow biopsies have been used to evaluate diseases of the blood for over a century. The contemporary biopsy needle, invented by the Iranian hematologist Dr. Khosrow Jamshidi in 1973, is almost comically long, long enough to reach the bone that is sometimes buried deep beneath the skin. It looks like a prop for a movie mad scientist. A few years ago, I probably forfeited any “parent of the year” aspirations I may have had by pulling one out at my son’s elementary school during a lesson to his classmates on how blood was made. Not surprisingly, they recoiled at the sight of it.

Patients can have the same reaction. An alternative to the needle is a drill that was shown in one study to be just as effective at obtaining bone marrow specimens. Though some patients have told me they feel less pain with the drill, others say it gives them even more anxiety, telling me it evokes the sounds they normally hear emanating from the dentist’s office.