As a pediatric hematology/oncology and palliative care fellow, I face my share of, "How do you do that?" "You must be a special person," or "That must be so depressing," comments. Up until this point, I have largely avoided the topic of what I do with my family, especially with my two daughters.

Over the years, the story I tell my children about what I do has changed. My first daughter was born in my fourth year of medical school, my second daughter in my third year of pediatric residency. Medicine, call, and pagers have been part of the fabric of their lives. At first, they would say, "Mommy is a doctor"; as they aged and could understand more, they would say, "Mommy is a pediatrician."

Somehow, it is easier to explain what Daddy does as a head and neck surgeon. The girls know that he cuts bad things out, that he fixes things. Sometimes he stays late because it takes a long time do an operation. Sometimes he gets called in the middle of the night to take someone back to the operating room. They get it. They eagerly ask to see "guts pictures" when he gets home, and they pour over anatomy books with the vigor of a first-year medical student. We taught them both at about age two how to say "otolaryngologist," which was more party trick than anatomy lesson. Perhaps unconsciously, we never taught them to say "oncologist."

"I don't want him to die, but if he does, then can you tell me his name?"

Most parents worry over how to answer the big questions, from the birds and the bees to why bad things happen, to even curiosity about death. What worried me more was how to tell my children exactly what I do. Death is not a taboo topic in our house. As Catholics, we have a crucifix hanging prominently in our home, and my children have attended funerals. If they ask, we answer. But somehow my job (especially the hospice part of my job) was off-limits.

What is this big part of my life that calls me away, sometimes every fourth night, sometimes every other weekend, on late nights past bedtime, from school events and soccer games? Some days I leave my children home sick to take care of other sick children, children who are not my own but who have been entrusted to me all the same. How do I weigh the importance of my febrile daughter, with a virus caught from day care, and my new patient, with leukemia, in the pediatric intensive care unit with a WBC of 400,000?

As my oldest daughter has grown, so has her understanding of my work. She knows that I work in the hospital and take care of sick children, which is different from the pediatrician she sees, who she calls the checkup doctor. Last year, I had a near miss with this big question after she overheard me answer the phone: "This is Melissa Mark with oncology." Her question, "What is oncology?" was easily brushed aside and redirected in the hubbub of a busy call night of returning pages in between bedtime stories and tuck-ins.