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Neuroradiology Case of the Week

Case 438

September 2009

Zhengjun Liu, MD and Lisa Siripun, MD

Clinical Presentation: Patient is a 43-year-old woman with a history of an L4/L5 fracture who presented with right radiculopathy and back pain. There was clinical suspicion for disc herniation causing root compression.

Imaging Findings:
CT: Vertebral hemangiomas are typified by punctate sclerotic foci representing thickened vertical trabeculae seen in cross-section and giving a polka-dot appearance.

Diagnosis: Vertebral body hemangiomas

Discussion:
Clinical discussion:
     Bone hemangiomas are benign, malformed vascular lesions, overall constituting less than 1% of all primary bone neoplasms. They occur most frequently in the vertebral column (30-50%) and skull (20%), whereas involvement of other sites (including the long bones, short tubular bones, and ribs) is extremely rare.
     There are four histologic variants of hemangioma, classified according to the predominant type of vascular channel: cavernous, capillary, arteriovenous, and venous. These types can coexist. Bone hemangiomas are predominantly of the cavernous and capillary varieties. Cavernous hemangiomas most frequently occur in the skull [1, 2], whereas capillary hemangiomas predominate in the vertebral column; overall, the former type is most common in bone [3].
     The large majority of lesions are asymptomatic; clinically significant symptoms develop in only 1-2% of patients. Hemangiomas should be treated only if symptomatic; treatment options depend on the site of the lesion, the severity of the symptoms, and the medical expertise available. Medical treatment and clinical observation can be used as first-line management, especially in patients with mild to moderate symptoms. Other treatment options are available when this does not suffice or when clinically appropriate [4, 5].

Image discussion:
     MRI features largely depend on the proportion of fat and vascularity of the lesions. With T1-weighted MRI, particularly in vertebral hemangiomas, areas of high fat content appear as areas of high signal intensity. On T2-weighted images, high signal intensity typically corresponds to the vascularity of hemangiomas. Low signal intensity on T1-weighted images indicates decreased marrow fat or a greater vascular component; such a finding may be correlated with more aggressive behavior and is also more characteristic in cases involving vertebral collapse.
     Thickened trabeculae demonstrate low signal intensity on MRIs obtained with all sequences. Extraosseous components tend not to show high signal intensity on T1-weighted images due to the paucity or absence of adipose tissue. Epidural extension and neural involvement are well depicted with MRI.

References:

1. Calisaneller T, Ozdemir O, Yildirim E, Kiyici H, Altinörs N. Cavernous hemangioma of temporalis muscle: report of a case and review of the literature. Turk Neurosurg. 2007;17(1):33-6. Review. PMID: 17918676 [PubMed]
2. Magliulo G, Parrotto D, Sardella B, Della Rocca C, Re M. Cavernous hemangioma of the tympanic membrane and external ear canal. Am J Otolaryngol. May-Jun 2007;28(3):180-3. Review. PMID: 17499135 [PubMed]
3. Naama O, Gazzaz M, Akhaddar A, et al. Cavernous hemangioma of the skull: 3 case reports. Surg Neurol. 2008 Dec;70(6):654-9. Epub 2008 Jan 22. PMID: 18207223 [PubMed]
4. Kahana A, Lucarelli MJ, Grayev AM, Van Buren JJ, Burkat CN, Gentry LR. Noninvasive dynamic magnetic resonance angiography with Time-Resolved Imaging of Contrast KineticS (TRICKS) in the evaluation of orbital vascular lesions. Arch Ophthalmol. Dec 2007;125(12):1635-42. PMID: 18071114 [PubMed]
5. Acosta FL Jr, Sanai N, Chi JH, et al. Comprehensive management of symptomatic and aggressive vertebral hemangiomas. Review. Neurosurg Clin N Am. Jan; 2008;19(1):17-29. PMID: 18156044 [PubMed]