 This young man has decreased attention span intermittently. Let's have a look at two MR images, one a non-contrast sagittal MRI, and the other on the right, an axial T2 water-weighted MRI. You can gaze at the images for a moment. I'm going to move forward and give you the first question. The most likely diagnosis is A, chiasmatic glioma. B, hypothalamic glioma. C, hematoma. D, cranioforengioma. E, clotted aneurysm. Question number two. Spoiler alert, you're going to get the answer. You can pause if you wish. I'm going to move on. Which of the following is false regarding hypothalamic hematoma? A, precocious puberty, usually less than two years. B, gelastic seizures or inappropriate episodic laughter and strange behavior. C, males greater than females. D, associated with obstructive hydrocephalus. E, between the infantibular stalk and mammillary bodies is the location. Question number three. Which of the following is false regarding imaging of hypothalamic hematoma? A, isointense on T1. B, maybe slightly hyperintense on T2. C, early enhancement. D, pedunculated or sessile. E, may project into the third ventricle. Okay, let's go back and have a look at our images. We have a sagittal T1 weighted image in which our mass has a very characteristic location. It looks like the tongue of the mammillary body is sticking down. See, there's the tongue. These lesions can be located right under the mammillary body or just behind it. But there is a small web-like area of communication with the pituitary stalk. These lesions involve the tuber scenario, which is part of the hypothalamic pituitary axis. They're also part of the limbic system, which includes the mammillary body, not seeing the mammalothalamic tract and structures that take you around the colosum, such as the singulum, into the temporal lobe. And there are more structures associated with the limbic system, but that is a story for another day. The lesion is smooth. The lesion is gray. In fact, it's virtually iso-intense with the gray matter. Although we didn't give contrast, typically there is little to no enhancement. In fact, most frequently there is no enhancement. The lesion can be separated from the pituitary stalk. The lesion can be separated from the optic chiasm and the optic tracts, which core surround it. Here in the axial projection is the lesion sitting right smack dab in the midline in front of the interpeduncular cistern. On T2 imaging, the lesion is gray. It's iso-intense with gray matter on T2. It's iso-intense with gray matter on T1 imaging. It contains no hemorrhage, no cyst formation, no calcification, and those are part of the visual criteria for this lesion or mass. Because they're not huge, they're not very big, they don't produce much interpeduncular cisternal widening. They don't splay out the carotid terminiac as they're a little bit too far posterior. And they don't directly involve the hypothalamic area, which is a little higher up in here, the hypothalamic area proper. And they don't involve the optic chiasm. This will come into play as we discuss some of our questions and their choices. So let's go back and take on question number one. The most likely diagnosis, well, it's easy now. It's hypothalamic hematoma of the tuberous scenario. It's a hematoma. In other words, it's not a glial neoplasm. It's a benign, dysplastic, low-grade abnormality that may produce some clinical symptoms, but not those of mass effect or obstruction. Unlike the hypothalamic true neoplastic glioma, which exhibits necrosis, and occasionally hemorrhage, but not too commonly, but fairly large size and interval growth and is located more in the hypothalamic region up in this area, it has a different locale, namely the tuberous scenario with that tongue-like protrusion beneath and sometimes behind the mammillary body. Unlike the chiasmatic glioma, it does not involve the optic chiasm. Sometimes you'll hear the term hypothalamic chiasmatic glioma in one phrase because both are involved. Craniopharyngeoma is not a good choice. These are not smooth, gray, homogenous lesions. Craniopharyngeomas calcify. They're also not associated with episodes of loss of attention, although there are other symptoms including visual pathway compression. It is not a clotted aneurysm. Craniisms have a laminated appearance consisting of vessel wall and fibrin and clot and flow. Vessels have areas of Y phase ghosting. In other words, in the Y or phase encoded direction, you'll see smearing of the signal emanating from the vessel. So it would look something like this. It would go across the vessel from side to side in the phase encoded direction. You would also see within a vessel flow void right there is the flow void if there was some patency in the vessel. And you'll like to see the aneurysm connected to the vessel. Our lesion is connected. It's connected to the limbic system, to the hypothalamic axis and the pituitary axis via this very thin thread or string. It is not connected to a blood vessel as an aneurysm would be. Question number two. Which of the following is false regarding hypothalamic hematoma? This one is easy. These can be pretty good sized lesions, but not giant. They're usually about two centimeters or less. But they are not associated with obstructive hydrocephalus. Therefore, this is the false answer and it is the choice for which of the following is false regarding hypothalamic hematoma. But the other choices are true. Patients will have precocious puberty. Gelastic seizures or inappropriate episodes of spontaneous laughter and strange behavior are associated with these lesions. Males are more commonly affected and sometimes you may see hematomas with areas of fat or just fat alone in the same locus, namely the tuber scenario. They are located between the infantibular stalk and the mammillary body. Back to our lesion, there's the infantibular stalk, there's the mammillary body, and there is the characteristic location in between that space of the two. Question number three. Which of the following is false regarding imaging of hypothalamic hematoma? The answer is easy once again. It's an easy set for you. You're going to get a lot of confidence from it. The answer is C. Early enhancement is not a feature of any hematoma. Just about anywhere throughout the entire body. This is basic blocking and tackling imaging and or radiology and medicine. They are because they're very close in character to gray matter. They are iso intense with gray matter on T1. They may be slightly hyper intense on T2 or iso intense on T2. Our lesion is virtually iso intense with gray matter. It has a little tiny nubbin of high signal intensity in the middle. Let's blow it up a little bigger so you can see it. Right there. And pedunculated or sessile is a characteristic of our lesion. Looks like a tongue hanging down. And occasionally they may project into the third ventricle. That is a true statement. So this is the hypothalamic hematoma. The important take home message, especially if you're taking an exam, is the location between the mammillary body and the pituitary stalk. Lobulated, pedunculated and absence of enhancement on contrast enhanced CT and MR with iso intensity to adjacent gray matter. Let's move on, shall we?