Some months ago, a colleague shared a nail biopsy with me. To me it looked like melanoma in situ. It was seen at a consensus conference we have every week with other institutions in the Houston area. Everybody who saw it thought it was melanoma in situ. The problem was that the patient was an eleven-year-old boy.

Given the age of this child, this case was sent in consultation to other experts. One expert opined that it was a junctional nevus with features of pigmented spindle cell nevus. Another expert said that it was a moderately dysplastic nevus, but then revised the diagnosis to indicate that the atypia was severe, and recommended complete excision. A decision was made to take the lesion out.

This brings me to the question: what’s in a name? The take home message for the clinician was that no matter what it was called, the lesion had to be completely excised. So did the name one give it really matter? I suppose the patient’s future insurance would be one thing that could be adversely affected by a diagnosis of melanoma. But should we be making diagnoses by insurance criteria?

The fact of the matter is that we are stumped when it comes to children and melanocytic lesions. It is well known that melanocytic lesions that look bad in children do not necessarily behave that badly. So what do we do when we are faced with a lesion that looks particularly ugly in a young child? Lesions that we would not hesitate to call melanoma in an adult cause pause when seen in children. And there is nothing wrong with pausing. In fact, we should pause, consume the data the lesion provides, and reflect on the findings we see. Post-pause is where the problem starts. Some of us may want to call it one thing, others something else, but I am not sure either party can be certain that they are right. They may [i]feel[/i] certainty, but they may be falling for what is known as the “affect” heuristic. This is name given to the bias whereby humans, which surely includes dermatopathologists, depend on gut feelings and emotions to come to a conclusion. (The feeling is the end-result of the experiences one has had, and I don’t mean to imply that the feeling is necessarily irrational).

I know some will argue (about some hypothetical case) that, “it has to be this-or-that because I saw another case like this and the patient went on to die.” Another might argue about the same case that “it has to be the opposite because I saw a case like this, and the patient is alive fifty years later.” Of course, in science we give a name to this kind of evidence: anecdotal evidence. Some of us may point to studies, like the ones in melanocytic lesions in children, but we all know examples when studies said one thing and the lesions “said” something else.

To return to the example of the case I began the discussion with: I am convinced that it is melanoma in situ, because it looked like one – to me. I was not alone in this – almost every experienced dermatopathologist in the Houston area (who was shown this case) believed it was melanoma in situ as well. Other experts in other part of the country thought otherwise. The end result was that almost all the dermatopathologists who saw this case recommended re-excision. The end result was the same.

We can’t help being ourselves. As the old saying has it, no matter how fast you run, you can’t run away from your feet. Our impressions and education have taught us certain things, and we can’t deny what we have learnt. But I think we should remember that no matter how sure we feel about certain things, this feeling of sureness is no guarantee that we are right.