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Neuroradiology Case of the Week

Case 109

Sarah Goldfeder and Per-Lennart Westesson, MD, PhD, DDS

Clinical Presentation: The patient is a 24-year-old male with a left-sided neck hemangioma. MRA of the head and MRI/MRA of the neck were requested to evaluate arterial involvement in the head.

Radiological Findings: MRA of the head was normal. MRI of the neck shows a large, multilobulated, cystic-appearing, superficial mass in the left neck. The mass does not encase the left common or internal carotid arteries, but does involve the left retromandibular vein and left external jugular vein. The lesion also involves the left parotid gland and likely encases the left facial nerve. There is an incidental finding of a dome-shaped soft tissue lesion in the right maxillary sinus, which is likely a retention cyst.

Diagnosis: Hemangioma of left neck involving the left retromandibular and left external jugular veins, but not left common or internal carotid arteries.

Discussion: Historically, differentiating a hemangioma from a vascular malformation has been a challenge for many physicians. In 1982, Mulliken and Glowacki described a classification system that distinguishes the two vascular anomalies based on their natural history, cellular turnover, and histology.
     According to Mulliken and Glowacki, hemangiomas exhibit cellular proliferation, are small or absent at birth, and undergo a two-stage process of rapid growth during infancy and involution during childhood. Vascular malformations, on the other hand, are compromised of dysplastic vessels, are present at birth, grow in proportion to the child, and exhibit no regression. Vascular malformations are further subdivided into lymphatic, capillary, venous, arteriovenous, and mixed type. Some examples of vascular malformations are the capillary “port-wine stain” seen in the Sturge-Weber syndrome, arteriovenous malformations, and arteriovenous fistulas.
     Hemangiomas are the most common tumor of infancy. They are benign and account for 7% of all soft tissue tumors. They usually present during the first month of life, and 96% are apparent by 6 months of age. By 7 years of age, 70% have resolved. They are more common in females, Caucasians, and premature infants, especially in those weighing less than 1000 grams. Sixty percent of hemangiomas develop in the cervicofacial region, and they can be superficial, deep, or visceral in location.
     Radiographic imaging can help distinguish hemangiomas from other lesions as well as define the extent of the tumor. MR is the preferred imaging method, but CT and angiography can also provide valuable information. On MR, the lesion appears as a lobulated soft-tissue mass with flow voids indicating feeding and draining vessels. T1-weighted images reveal the lesion to be isointense or hypointense to muscle, while T2-weighted images reveal it to be hyperintense. There is homogeneous enhancement with contrast. CT shows similar findings to MR. Angiography reveals the hemangioma to be a well-circumscribed mass with parenchymal staining and feeding arteries and draining veins.
     Although hemangiomas are benign lesions, they can be associated with certain serious syndromes. The PHACES syndrome is one in which there are posterior cranial fossa malformations, hemangiomas, arterial anomalies, cardiac anomalies, eye anomalies, and a sternal cleft and/or supraumbilical raphe, which are ventral developmental defects. The Kasabach-Merritt syndrome is associated with two specific subtypes of hemangiomas: kaposiform hemangioendotheliomas and tuft angiomas. In this condition, there is thrombocytopenia, anemia, and consumptive coagulopathy. Other complications that may occur from a hemangioma are compression of vital structures, ulceration, fissure formation, infection, bleeding, visual impairment, airway obstruction, auditory canal obstruction, and congestive heart failure. If serious complications develop, mortality may be as high as 20-30%.
     As most hemangiomas are not life threatening and will eventually undergo spontaneous involution, therapy is not usually required. However, if there is functional impairment and/or emotional distress, oral corticosteroids with interferon is recommended as first-line treatment. Excision, chemotherapy, and radiation may also be attempted for unresponsive lesions.

References:

1. Som and Curtin: Head and Neck Imaging, 4th ed., Volume One. 2003 Mosby: 1852-1858.
2. Gampper TJ, Morgan RF.  Vascular anomalies: hemangiomas. Plastic and Reconstructive Surgery. August 2002: 572-585.
3. Donnelly LF, Adams DM, Bisset GS III.  Vascular malformations and hemangiomas: a practical approach in a multidisciplinary clinic. American Journal of Roentgenology. March 2000. 174: 597-607.
4. Metry DW, Dowd CF, Barkovich AJ, Frieden IJ.  The many faces of PHACE syndrome.  The Journal of Pediatrics. July 2001. 139(1): 117-123.