 Well, those are the acute problems that we commonly see. The torsion is the one that obviously needs quick surgical intervention because you can't salvage the ovary. The cyst obviously needs the correct diagnosis so that patients can be treated appropriately. But that's conservative usually with pain medications. Well, pelvic masses can also produce pain or present as a mass and then we use ultrasound. If there's a mass in the abdomen, pelvis, we start with ultrasound. CTRMR used if ultrasound is equivocal or if we think there's a malignant mass, then we stage it with one of these two. One thing about tumors in general in kids, epithelial tumors are rare any part of the body in children. They're really rare. In adults, and I do a lot of adult cancer work as well, we're talking about adenocarcinoma and that's not what it is in a child. In a child, think of a simple cyst, a dream cell tumor or stromal tumor. Those are embryonic tumors. They're not adenocarcinoma. So ovarian masses, we'll look at cystic ones, teratomas, cystanoma, and the solid ones are the germ cell and brinal tumors and the sex card stromal tumors. The teratomas, the common ovarian neoplasm of the ovary, most are benign. They may present just as a large mass but they can cause pain due to torsion or just pressure from the large mass. And again, most of what we're talking about is the adolescent population. They're big pathologically. Moon diameter of 15 centimeters. They're cystic because they have a lot of sebaceous material and sebum is liquid at body temperature. They contain a peripheral nodule, the Rokotansky nodule, which can contain fat, calcium bone, and teeth. So this is what it looks like. It's a hypochoric, anechoic mass, but it has peripheral nodules. If you see a girl with a pelvic and sometimes these are big enough to be abdominal masses, always think about ovarian and look for both ovaries. If you see only one, think about an ovarian mass. And children are large enough to go up in the abdomen. And the teratoma has the peripheral nodules. We do CT for correlation and you can see the fat and the calcification. Another appearance of the teratoma, pelvic mass, hypochoric, ecogenic material, anterior, the tip of the iceberg sign. This is usually fat or hair. Here's the CT. There's some fat and there's some hair. Teratoma. The other lesion, cystic lesion we see is the cystiaenoma. It's not really common. It's 5% of ovarian neoplasms. This is an epithelial tumor. And children, they're benign. Muesonists occur more than serous and they're big. They're huge. Kids are small and these are big. So the muesonist one has a lot of septations. It's multilocular because it has a lot of gelatin within it. It's thin-walled. You know, it looks like a mesenteric cyst. That's the alternative diagnosis. Just remember, in a girl, if you see a cystic mass or a solid mass in the pelvis or lower abdomen, look at the ovaries because it can come from the ovaries. This is a muesonist cystiaenoma. The serous cystiaenoma contain watery contents. There's thin-walled. You know, like occasionally you see a few septations. So this patient had pain and here's the mass. It looks like an anexil cyst. It's big, much larger than a cyst. We did bring this patient back and never got smaller. Went to surgery. It's a serous cystiaenoma. And here's another one. Huge mass with a few septations. Brought him back once or twice, never got smaller. It was a serous cystiaenoma. And malignancies, germ cell tumor, far, far away, just the number one diagnosis, stromal tumors. And then epithelial tumors, very rare. Malignum germ cell tumors. As I said, most keratomas are benign. A few will be malignant. Benign keratomas, benign lesion cystic, solid tumors are malignant. And again, these affect people or girls. The tissue type include dysgermanoma, amateur keratoma, endosyndermal sinus tumor, and embryonic cancer. We really can't separate these. There's a histologic diagnosis which may affect the type of drug the patient gets. Malignant tumors are once again huge. They're solid or complex. They have a lot of soft tissue, predominantly soft tissue. And these metastasize to local and distant lymph nodes and liver. They do not, you know, go to the peritoneum or mesentery similar to ovarian cancer. So a couple of examples. 15-year-old girl, palpable mass. And the pelvis, it's only one ovary. This is an ovarian mass, predominantly solid, predominantly solid. Turned out to be a dysgermanoma. 17-year-old girl, right lower quadrant pain, big mass, predominantly solid, a few cystic or necrotic areas. Some internal flow, given the age factor comes from the ovary, it's solid. It's a germ cell tumor. This was endodermal sinus. Sexchord stromal tumors, another group of tumors. And this is your clue. They affect pre-puberal girls. There are two types, granulosa thica and sertollelitic. They're active. That's your clue. The granulosa thica produces estrogens, the sertollelitic androgens. Most are low-grade malignancies. They may go to peritoneum and liver. Both are solid. They're large. They have areas of necrosis and hemorrhage. And they're heterogeneous. Five-year-old girl, breast development, remember I said they're hormonally active. Here's an ovarian mass. It's got some flow in it. Here's the CT, five-year-old girl with precocious puberty. It's a sexchord stromal tumor granulosa thica. Six-year-old girl with virilization. We start with an ultrasound, big mass in the pelvis. Virilization, pelvic mass, sertollelitic. We know that even before they go to surgery, that's sertollelitic. An ovarian cancer is really rare, less than 1% of cases. It is epithelial. It's a solid mass. Mean sizes like 4 cm or less, much smaller than the other tumors. And it does go to mesentery and omentum. Ovarian mass in this adolescent patient with abdominal pain. This is a mental metastasis. Here's more, you can see this is the periphery of the abdominal wall. More mental metastasis. CT, ovarian mass, and omental caking ovarian cancer. So ovarian masses, teratoma, cystic, peripheral nodules. The cyst adenoma, cystic, the miscellaneous one has septations. The serious one looks like just a big, simple cyst. And then if it's solid, it's malignant. In the adolescent girl, germ cell tumor, and in the pre-pubertoid girl, the sex squared stromal tumor. And then quickly, uterine mass is just cystic or solid, cystic hydrocopus, solid rhabdo. Hydrocopus is vaginal obstruction due to stenosis or a membrane, and the result is a pelvic or pelvic abdominal mass. We see it in neonates and in adolescents. And it's simply a distended vagina. Copos is vagina. Distended vagina. It may have debris or blood. If it has blood, it's called hematocopos. And occasionally you can see blood in the uterus, hematometrocopos. Neonate, distended vagina had a pelvic mass. This is the cervix, and this is the uterus. Had an imperfect membrane. Adolescent with pain every month, no periods. Distended vagina. It's the vagina that distends. The uterus is normal. Had an imperfect membrane. Hydrocopos, this had blood products, hematocopos. It's an easy diagnosis. Another adolescent with pelvic pain. Huge, distended vagina. And the tumor of the vagina and cervix is rhabdomyosarcoma. It's the most common pelvic tumor. It's the small blue cell tumor. Has a bimodal age distribution under six and then adolescent patients. But it rises in the vagina and the cervix, not the uterus. So the bottom line here is that the diseases, the pelvic organs, the tumors, the tumors of the vagina and cervix, not the uterus and your child and an adolescent. It presents with vaginal bleeding and it presents a soft tissue mass on imaging and the metastases go to liver, lung, nodes and bone. Two year olds. So what would you do with this? You see something behind the bladder. Is it rectum? I don't think so. Look at the long axis view. This is that pre-pupillary uterus I showed you. This little tube. This is the vagina filled with tumor, rhabdomyosarcoma. And here's a five year old girl with vaginal bleeding. Here's the uterus. It's probably got some blood product in it. This is the vagina. Very vascular. Here's the MR. That's rhabdom. Large heterogeneous mass. So common pelvic lesions, what you need to know, functional and very insist, are really common. There are tumors that are cystic. Cystic teratoma cystiaenoma. The malignant tumors are solid. That's your clue. They're usually germ cell tumors. And then the pre-pupillary sex cord stromal tumors, they're functional. And then in the vagina and the cervix, the benign lesion is hydrocopos. And if it's malignant, it's rhabdomyosarcoma.