Infantile hemangioma

Infantile hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They can occur virtually anywhere, but the majority are found in the head and neck regions.

This article aims to be a generic discussion of the condition, for detailed and more specific imaging features, please refer to the sub-articles:

• orbital infantile hemangioma
• parotid infantile hemangioma

Epidemiology

There is a prevalence of 1-2% in neonates, and by 1 year of age, there is a prevalence of 12%. Females, Caucasians, and premature neonates are disproportionately affected.

Clinical presentation

They are characteristically small or absent at birth. During the first year of life, they have a proliferative phase with progressive enlargement, followed by a stationary period, and finally, a progressive involution that happens during early childhood. Up to 50% involute by 5 years and 70% by the age of 7 years.

Cutaneous hemangiomas can present as blanching skin lesions that develop fine telangiectasias and can appear as a red macule with a blanching halo before they involute. Deep or subcutaneous hemangiomas may appear as bluish nodules or plaques. Extra-cutaneous hemangiomas present as lumps.

Pathology

These tumors proliferate both through the growth of existing vessels as well as de novo blood vessel formation. Hemangioma progenitor cells, endothelial cells, and pericytes are the histologically identified cell types that comprise these lesions. Unlike other vascular tumors, they are GLUT-1 positive.

Associations

• PHACE syndrome
• LUMBAR/PELVIS/SACRAL syndrome

Radiographic features

Ultrasound 

Infantile hemangiomas are predominantly superficial soft-tissue lesions and thus can be easily assessed by ultrasound. They present as an echogenic well-defined mass that may exhibit prominent internal vascularity on color Doppler ¹. High flow arterial and low resistance venous waveforms are demonstrated.

CT

Lobulated mass with the same density to the adjacent muscles and exhibiting a vivid and homogeneous contrast enhancement. They do not contain phleboliths.

MRI

Typical signal characteristics include:

• T1: intermediate signal, between that of muscle and fat
• T2: hyperintense, although small areas of hypointensity may be present (flow-voids, fibrous tissue, or calcification) 
• T1 C+ (Gd): homogeneous enhancement

Treatment and prognosis

These lesions are often initially observed. If treatment is to be enacted, options include anti-angiogenesis medications such as propranolol, embolization, sclerotherapy, radiotherapy, cryotherapy, laser therapy, and surgical excision ⁵. Complications such as the formation of fissures, bleeding and ulceration; Kasabach-Merritt syndrome, and compression of the airway or orbits may require treatment of the underlying hemangioma.

Differential diagnosis

• other arteriovenous malformations
  • ​multiple flow voids
  • feeding and draining vessels
• angiosarcoma
  • very rare
  • significant soft tissue component
  • may be heterogeneous
  • intense areas of contrast pooling with heterogeneous enhancement
  • accelerated growth
• veno-lymphatic malformation
  • prominent cystic spaces
  • minimal contrast enhancement