Dermoid Cyst with Dr. Rebeccah Brown

As we know, the differential diagnosis for soft tissue masses in children spans congenital anomalies, benign growths, inflammatory lesions, and the occasional malignancy. But nailing down the exact diagnosis can sometimes be elusive. Today, Dr. Rebecca Brown is going to share her diagnostic tips and tricks in our Lump and Bump Stay Current Short. Okay. So, let's get started with a case. This is a little 11 month old male who comes in with a lump over the right eyebrow. It's been present since birth. It's been increasing its size. The parents say, well, he might have fallen and hit the coffee table. So, sure, sure, it could be a lipoma or an inclusion cyst, or with that history, maybe even a hematoma from the suspected fall. Right, it's kind of skin colored. I don't see any bruising. It doesn't look like he, you know, he's, it's traumatic, per se. So, if not traumatic and in this classic location, a dermoid cyst rises to the top of the differential. The discussion on which of these to image is dependent on the location on the face. Those in the glabella region need imaging, but in this location, it's unnecessary and moving right to excision is appropriate. So, you're going to take him to the OR and you're going to excise that. Of course, excisions on the face are sensitive due to the added concern of cosmesis. But the proximity of the eyebrow can really help here in covering the scar into the eyebrow line. And it can really lead to a great cosmetic result. So, this is where you can sort of do it like in the eyebrow, uh, kind of line. And you never want to shave eyebrows, they never grow back right. So, make sure they don't do that. Um, but this is a way that, um, I've seen and I've done it one or two times, um, where you can use actually sort of the upper sort of eyelid crease and it kind of hides it very, very well. And you can actually you have enough mobility there to go up on the top and you'll be able to dissect down, uh, to the, uh, to the dermoid cyst. The extremely mobile tissue along the upper eyelid really allows for an adequate dissection below the muscular layer to remove the dermoid cyst, which is really seated in that underlying bone and can reduce the rate of rupture. It's kind of like sitting in a bowl. It's like sitting in it's like scalloped in the bone, okay, because these these tend to occur in places where bones kind of come together and it's kind of scalloped in the bone and it kind of comes out like almost like in a cup. Of course, rupture of the cyst is never ideal, but resection with rupture just requires extra care to wash out the cavity and remove any obvious remaining portions of the cyst. Finally, Dr. Brown curettes the cavity and the periosteum. And then I'll usually kind of scrape or kind of curette the periosteum there as well and then do your closure. And here we go, straight into our next case. This is a six month old kid who has a lump in the posterior parietal, um, scalp. It's, it's kind of, uh, it doesn't move very much. It's, it's kind of immobile. It, yeah, you just have a nice little round, well circumscribed kind of mass there and it's not really moving very much. Okay, so the immobility obviously narrows the differential, taking things like enlarged lymph nodes really off the table, even though they're relatively common in this parietal region. Further imaging can delineate the source of this tethered lesion and identify a key feature. What you're trying to figure out is what this is. Um, it looks like a cystic lesion. But what you're trying to figure out is does it go into the cranium, right? Is it intercranial? Does it have intercranial extension? And so while a CT scan or ultrasound in young patients might answer that question, we haven't quite identified a diagnosis. This is fairly classic for a little dermoid cyst of the scalp. And the thing that you want to know is does it have intercranial extension. And so while dermoid cysts may appear to be tethered to the scalp, really that bull-like scallop seating within the bone is what gives it that effect. And so this lesion gets excised as well. And then this is what they, uh, typically look like, uh, when you take them out. It's the same kind of, kind of yellowish kind of, uh, cream cheesy kind of, uh, thing. Thanks for joining our Stay Current Short on dermoid cysts. Remember to download the Stay Current app, check us out on YouTube, Facebook, and Twitter. But until next time, I'm Brittany, and remember, knowledge should be free.