Clinical diagnosis
Case 196
【Progress】
She was admitted for a few days and discharged after her fever dropped to normal temperature without special management.
【Discussion】
Brain CT images in our case mimic localized hemorrhage in the right frontal lobe. Further, the lesion appeared almost homogeneous low signal intensity on MRI with T2*WI, indicating hemorrhage. The hemorrhage was found at the deep white matter and extends to the frontal cortex. She experienced headache, which seemed to be compatible with local hemorrhage. But brain MRI showed a lesion with rim of low signal intensity on T1WI and T2WI. The core inside the lesion was iso to low signal intensity on T1WI and high signal intensity on T2WI, indicating aged hemorrhage or cavernous hemangioma.
Cavernous hemangioma occurs sporadic in brain, liver, skin and so on. It consists of grossly dilated vessels; various-sized caverns whose surface is covered with endothelium. Macroscopically, it looks like raspberry or multiple bubbles. Blood flows very slowly its inside. Since it does not own the envelope or outside capsule, blood can leak outside from the weak point (1-4). Then, brain hemangioma has hemosiderin layer like envelope. It appears as low signal layer of the lesion on T1WI and T2WI. The inside core has a cluster of cavern which appears low signal intensity on T1WI and high signal intensity on T2WI. Meanwhile, liver hemangioma does not have the low signal layer. It is probably because liver itself has sinusoids and the leakage of blood from hemangioma easily flows to sinusoids. Then, the liver hemangioma does not have hemosiderin layer, implying that the core appears as high signal intensity on T2WI and low signal intensity on T1WI.
MRI with T2*WI is useful to check deoxyhemoglobin, methemoglobin and hemosiderin, indicating various stages of hemorrhage. T2*WI is available for patients with hemorrhage, microbleeds, hemangioma, superficial siderosis, thrombosed aneurysm and middle cerebral artery susceptible sign (5, 6). Further, T2*WI is also available for patients with disorder of knee or shoulder plate because cartilage becomes more hyperintense, while bone becomes hypointense.
Brain CT demonstrates cavernous hemangioma with iso-density to mild hyper density and without mass effect. When hemorrhage occurs, it may be possible not to realize the presence of hemangioma. The symptoms of cavernous hemangioma include seizure, neurological defect, headache and silent, depending on the location of the lesion (1-3, 7).
Brain cavernous hemangioma appears one out of 500-600 people, 0.2% of the general population. The onset age is 20 to 40ies (2, 3). Then, when hemorrhage is detected on CT in young adults, cavernous hemangioma should be listed for differential diagnosis. Our patient was fifty four year-old, suffering from headache. Brain CT showed small-sized hemorrhage in the left frontal lobe.
【Summary】
We present a fifty four-year-old female suffering from persistent fever, headache and consciousness disorder. Brain CT showed a small lesion with iso to mild high density at the right frontal lobe. Brain MRI showed a lesion was homogeneously hypointense on T2*WI, while hypointense with marked low rim on T1WI and hyperintense with marked low rim on T2WI, indicating compatible with cavernous hemangioma. It is borne in mind that brain hemangioma has low signal rim on T1WI and T2WI probably because blood leaks to the outside, indicating deposition of hemosiderin, while liver hemangioma does not probably because leakage moves to liver sinusoids. Low signal intensity on T2*WI reflect deoxyhemoglobin, methemoglobin and hemosiderin. When hemorrhage in young adults is found on CT, hemorrhage from cavernous hemangioma should be differentiated from hemorrhage from hypertension.
【References】
1.van Lindert EJ, et al. Giant cavernous hemangiomas: Report of three cases. Neurosurg Rev. 2007;30:83–92.
2.Sage MR, et al. Cavernous haemangiomas (angiomas) of the brain: clinically significant lesions. Australas Radiol. 1993;37:147–55.
3.Simard JM, et al. Cavernous angioma: a review of 126 collected and 12 new clinical cases. Neurosurgery. 1986;18:162–72.
4.Hauck EF, et al. Symptomatic brainstem cavernomas. Neurosurgery Jan 2009;64(1):61-70; discussion 70-1.
5.Ide C, et al. MR features of cavernous angioma. JBR-BTR Dec 2000;83(6):320.
6.Rigamonti D, et al. The MRI appearance of cavernous malformations (angiomas) J Neurosurg. 1987;67:518–24.
7.Maggi G, et al. Cerebral cavernous angiomas in critical areas. Reports of three cases in children. J Neurosurg Sci. 1997;41:353–7.
2020.7.1