Imaging Studies
The most important imaging tool for this condition is contrast-enhanced MRI. [5, 6] This diagnostic test, which requires sedation or general anesthesia for children younger than 6 years, demonstrates the extent of the lesion and helps differentiate between hemangiomas and venous, lymphatic, and arterial lesions. It may also help differentiate between a vascular lesion and nonvascular lesions, such as those found in neurofibromatosis.
-
MRI scans have 3 basic images: T1-weighted spin-echo image, T2-weighted spin-echo image, and contrast-enhanced (gadolinium) T1-weighted spin-echo image. T refers to the time necessary for the protons to discontinue spinning. T1 refers to a value of approximately 600 milliseconds and T2 refers to a value of about 4000 milliseconds. The typical findings in the 3 image modes are presented in the second image below.
-
Hemangiomas have a typical solid appearance with intermediate intensity on a T1-weighted spin-echo image, which is more intense than venous or lymphatic malformations. [5]
-
During the proliferative stage, hemangiomas show a relatively low intensity in a T2-weighted spin-echo image; in the involution phase, they have a very low intensity.
-
Contrast-enhanced T1-weighted MRI shows moderate intensity with prominent flow voids during the proliferative stage because of the high flow at this stage. In contrast, hemangiomas show low intensity during involution as a result of the low flow at that stage.
-
The first image below shows a 5-year-old boy with a left intraorbital hemangioma that had caused vertical dystopia of the left globe. The second image below shows the contrast-enhanced T1-weighted image with visible flow voids and intensity, typical for hemangiomas at the proliferative phase.
Doppler ultrasonography can assess the flow of hemangiomas. [7] Generally, they are characterized by a shunt pattern with decreased arterial resistance and increased venous velocity.
Arteriography is rarely used for diagnosis or treatment of hemangiomas. Superselective embolization may be used in selected bleeding hemangiomas with a detectable regional nourishing vessel.
Histologic Findings
Proliferating hemangiomas are composed of clusters of rapidly dividing endothelial cells (see the image below). With regression, endothelial activity gradually diminishes and the cells flatten and mature. Mast cells appear in the late proliferating phase and early involuting phase and interact with macrophages, fibroblasts, and other cell types. [3, 8] During involution, light microscopy demonstrates progressive deposition of perivascular and interlobular/intralobular fibrous tissue. Multilaminated basement membranes, an ultrastructural hallmark of a proliferative phase hemangioma, persist in the involuted phase. [3, 8]
Most endothelial cells and pericytes express proliferating cell nuclear antigen in the proliferative and early involuting phases. [20] Its expression is negligible in the involuted phase. [20] The total number of mast cells is highest in the involuting phase, and the proportion of chymase-positive mast cells decreases with the progression of involution. [20] Type IV collagen and the 2 chains of laminin and perlecan are detected in the basement membranes in all phases. [20]
-
Hemangiomas. Classification of vascular lesions.
-
Hemangiomas. Classification of vascular malformations.
-
Hemangiomas. Diagnosis - Medical history.
-
Hemangiomas. Diagnosis - Physical examination.
-
Deep cheek hemangiomas.
-
Superficial cheek hemangiomas.
-
Upper lip hemangiomas.
-
Treatment with steroids of orbital hemangioma.
-
Panfacial hemangiomas.
-
Resection of a bleeding forehead hemangioma.
-
Lower lip hemangioma with intraoral extension.
-
Hemangiomas. Relaxation time - MRI T1, T2.
-
Hemangiomas. Diagnosis MRI.
-
Left orbital hemangioma.
-
MRI of orbital hemangioma.
-
Proliferating hemangioma - Light microscopy.
-
Hemangiomas. Facial nodular fasciitis misdiagnosed as a vascular lesion.
-
Differential diagnosis of orbital hemangiomas.
-
The effect of compression on a chest hemangioma.
-
Use of a bicoronal approach to resect a forehead hemangioma.
-
Types of nasal hemangiomas.
-
Resection and primary closure of a nasal bridge hemangioma.
-
Open rhinoplasty approach to resect a nasal tip hemangioma.
-
Lower lip hemangioma.
