The WOEs of Radiology

April 19, 2021
Eric Postal, MD

When something you see on an image stops you in your tracks.

Chugging along through my work list this past week, I was stopped in my tracks by a honking-big liver mass that stymied my brain’s pattern-recognition circuits. I’ve come to think of such abnormalities as WOE lesions (“What on Earth…?”).

A WOE differs from a “Whoa!” lesion, although this particular mass qualified for the latter category, too: Big enough you could see it from across the room, bad, and/or a striking change from prior comparison studies.

The initial challenge with a WOE is knowing for sure that it isn’t something you’ve seen before. Okay, you haven’t seen anything like it lately, but there are only so many abnormalities out there, right? So the first thing that happens is a ransacking of the long-term memory for something that might not even be in its cobwebby recesses.

Answers not being found within, external sources take over. It used to be higher on my list of options to ask a relevant-subspecialty teammate what he thought. However, now that I’ve seen 20-plus years of imaging studies, it’s become way too common that a case making me say “What on Earth…?” will prompt the same mystified reaction from my chosen consultant. I’m more likely to waste his time (and my own), possibly embarrassing him, than I am to get a solid answer.

So I start hitting various references, thanking my lucky stars that the Internet has long since supplanted the chore of reaching for my bookshelves and turning pages in search of, again, something that they might not contain. Sometimes, I hit paydirt: The web coughs up an article showcasing my WOE, or at least something resembling it enough to make me feel vaguely competent if I offer it as a diagnostic possibility.

But, again, if something was weird enough to make me say WOE, that’s an uphill battle. Maybe there aren’t any look-alike cases out there. Maybe I didn’t choose the right search terms. Maybe I did, but the answer I sought would’ve been on the eighth page of Google-hits and I gave up on the fifth.

At this point, I might finally be willing to risk wasting a colleague’s time by begging for an assist. There are still times this works; I don’t think I’ll ever reach a point in my career when I won’t consider it. At the very least, it can be satisfying to see that someone wiser than me is equally stymied; ignorance, like misery, appreciates company. It’s also useful to hear a trusted source tell you what they think a WOE almost certainly is not, so you don’t go ahead and mention wrong possibilities in your eventual report.

So the WOE might not be something that’s previously offended your eyes, nor those of your trusted sources. Rare things do exist…and it’s not impossible that you’re the first person who’s ever seen a particular bit of pathology. Or, as they used to say about some cases from Louisville oral board exams, an “atypical presentation” of a common entity.

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For whatever reason, it’s pretty much unheard of for a rad’s report to plainly say, “I don’t know what this is, and haven’t been able to figure it out.” Instead, we get descriptive: The thing is this size, has that density/signal/avidity, enhances (or fails to) in such a way.

I, then, imagine a conversation I’m having with the clinician who referred the WOE. (After the awkward “What is it?” “I dunno.”) The next questions s/he’d ask would probably be along the lines of “Do I need to worry about it?” and “How do we figure out what it is?”

So, I emphasize things like rate of growth, aggressive/destructive features, or the reassuring absence of such things. Ordinarily, I do everything possible to avoid pointing out another rad’s “miss,” but sometimes it’s a necessary evil here. For instance, my liver WOE from this past week was present on a CT from over a year ago…but, the CT’s reader hadn’t noticed it. As it was retrospectively stable, at least I could say that it wasn’t a rapidly-growing cancer or rampant infection.

(I also made sure to point out that it was extremely subtle on that prior exam, which was a CTPA, whereas my current MR rendered such pathology far more conspicuous. I feel like, if you’re going to talk about a colleague’s miss on the record, you should do what you can to explain why the miss wasn’t that bad.)

Then, I consider whether there’s information I’m missing, and “think out loud” about it in my report. If I haven’t been given any relevant prior studies, that doesn’t mean they don’t exist. I’m very free with suggesting that every effort be made to determine whether priors might be retrieved from other facilities, or at least reports of same. If the clinical history I was given seems at all scant, I’ll point out that missing details from it could turn out to be relevant.

I suspect I’m closer to the conservative edge of the rad spectrum when it comes to suggesting further imaging, especially follow-up studies of the same type that are currently failing to provide a diagnosis. Still, sometimes that seems to offer the best chance of getting answers: They didn’t do this scan with contrast, so let’s try including IV next time. The patient was breathing and moving around during this study; let’s do another with special efforts at avoiding that. The lung lesion was kind of buried in dependent atelectasis during this CT; let’s do the next one prone.

One thing I’d urge folks presented with a WOE: Try not to be overwhelmed by the negative aspects of the situation. Yes, it’s a challenge. You might not get the right answer. You might even wind up looking less than your best, when all’s said and done. But really, how frequently do you get to see something new at this stage of your career? Enjoy the tussle of blazing your own trail. You can nestle in your well-trod comfort zone while you do the other 99.9 percent of your job.

Follow Editorial Board member Eric Postal, M.D., on Twitter, @EricPostal_MD.