Case Based Pediatrics For Medical Students and Residents
Department of Pediatrics, University of Hawaii John A. Burns School of Medicine
Chapter XXI.3. Hemangiomas, Vascular Malformations and Nevi
M. Stanton Michels, MD
November 2002

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A 12 month female is brought in by her mother because she afraid that her daughter has a skin tumor. What started as a small red spot on her cheek has recently grown to almost the size of a dime. It now "sticks out" and can be palpated with a bulging appearance. Mom is also concerned because other people have remarked about the lesion, but the child seems unconcerned as it seems to cause no pain.

The child's exam is normal except for a 1 cm bright red strawberry colored mass on her cheek which is elevated approximately 4 mm higher than the surface of her skin. You advise her parents that this is a strawberry hemangioma which should resolve on its own. Surgical removal is not advised since this will result in more scarring than letting it involute on its own.


Various methods of categorizing congenital vascular lesions have arisen. One common grouping is to separate these entities into: 1) Hemangiomas, sometimes termed vascular nevi, and 2) Vascular Malformations.

Hemangiomas are defined as benign neoplasms with proliferating vascular endothelium. This endothelium enlarges, stabilizes, and finally undergoes involution. Vascular malformations on the other hand, are hamartomas of mature endothelium that do not proliferate. Hemangiomas are also more common in females with at 3:1 or even 5:1 ratio. This may be related to the common finding of high levels of estrogen receptors in the proliferating lesions. Hemangiomas are usually single lesions, but multiple lesions occur in less than 25% of cases. If one measures H-thymidine uptake in these lesions, one finds increased proliferation. Another interesting feature is the number of mast cells in these lesions on microscopy is up to 10 times the number in otherwise normal tissue.

There are well-defined stages of hemangiomas: proliferate, stationary, and involutional phases. Characteristically the lesions grow and become more protuberant over a period of time and adopt the typical raised configuration of the "strawberry" hemangioma. Then they slowly regress and in about 75% of cases, they completely disappear by age 7 years. Overall spontaneous resolution occurs in greater than 90%. Treatment is usually discouraged because a variety of techniques including surgery, cryotherapy, laser therapy, injection of sclerosing agents, and photocoagulation have all caused scarring that is unacceptable compared to the typical spontaneous resolution.

One particular type of hemangioma should be mentioned, Kasabach-Merritt syndrome. In this condition, the hemangioma is very large and extends to deep structures. Complications can include disfigurement; high output cardiac failure, infection and thrombocytopenia with acute or chronic consumptive coagulopathy as in DIC.

Vascular malformations make up about two thirds of all lesions in the newborn. Common vascular malformations include the "salmon patch" which are extremely common and usually fade spontaneously, and the "port wine stain" or nevus flammeus, which is permanent. Port wine stains occur in 0.3% to 0.6% of children. When this occurs on the posterior neck, it is termed the "stork bite", or on the eyelids, the "angel's kiss". Most of the lesions on the face fade with time. Some of the occipital patches persist.

Unlike the hemangioma group, the port wine stains are composed of mature capillaries that are limited to the dermis alone. As the number of vessels increases and age, the color can change from bright pink to dark purple. As facial port wine stains age, the vessels undergo progressive ectasia, developing a dark violet hue and often a roughening skin texture. The can lead to considerable emotional impact on the part of the child and the parents as well. Laser treatment is available for this condition. Certain parts of the skin act as targets that absorb specific wavelengths of light. The light is converted to heat, which destroys the target. Careful selection of the wavelength administered can direct precise treatment with minimal peripheral destruction. This tends to decrease scaring, although some degree of scar formation is always possible.

There are several syndromes that can be associated with vascular malformations. The most common of these is Sturge-Weber Syndrome. Externally, this presents with a port wine stain over areas of the face innervated by the first division of the trigeminal nerve (V1). The significant hidden finding is the ipsilateral leptomeningeal angiomatosis. Classically this produces railroad track calcifications of cortical vessels seen on plain skull films. CT may show these cortical calcifications earlier in life than routine X-ray. Other concomitant findings include seizures in 55-97%, mental retardation and various eye findings including glaucoma, visual defects, optic atrophy, cataracts, retinal detachment and heterochromia of the iris. For this reason, CT is advised for the infant with a port wine stain in the first division of the trigeminal nerve distribution. Serial ophthalmologic examination is necessary to screen for glaucoma.

Nevi are collections of normal melanocytes. The lay public terms these moles. The greatest concern about them comes from the fact that some undergo malignant transformation to melanoma. Nevi fall into several classes.

Giant congenital nevi are defined as being greater than 20 cm in diameter. 6% of these will turn malignant within the individual's lifetime. Therefore, most authorities feel that they should be removed if at all possible. Sometimes the location or extent makes removal very difficult. Some practitioners advocate the removal of all congenital nevi, regardless of size because of this theoretic danger.

Acquired melanocytic nevi, or common moles can appear at any time after birth. They are often divided into 3 common types: 1) Junctional nevi have melanocytes that are limited to the epidermis. 2) Compound nevi have nevus cells both at the dermal-epidermal junction and lower inside the dermis. They frequently are raised but smooth bordered. 3.) Intradermal nevi have nevus cells completely within the dermis. These are raised, dome shaped, and smooth bordered. There is the theoretic possibility of malignant transformation in these nevi as well, but the rate is so low that these nevi do not need to be removed.

Lentigines are small, (less than 1 cm), hyperpigmented macules which unlike freckles, can develop on sun exposed skin but also on unexposed areas of the body. Several syndromes may be associated with lentigines. The most well known of these is Peutz-Jeghers syndrome. This entity also includes characteristic pigmented lesions on the lips and oral cavity. It is dominantly inherited, but what is most problematic is the associated intestinal polyps which may cause cramping or bleeding.

Café au lait spots are another type light brown hyperpigmented lesions, which if more than 5 or 6 in number can herald neurofibromatosis or von Recklinghausen's disease.


Questions

1. True/False: Proliferating vascular endothelium can be arrested with laser treatment.

2. True/False: The concerned parent whose child has a protuberant, growing vascular lesion in early childhood can often be reassured that the lesion will involute with time.

3. Common manifestations of Sturge-Webber Syndrome include all of the following except:
. . . . . a. Meningeal vascular malformations
. . . . . b. Choanal atresia
. . . . . c. Homonymous hemianopia
. . . . . d. Mental retardation

4. True/False: Like most hemangiomas, Kasabach-Merritt Syndrome lesions tend to involute with time, but do not disappear.

5. True/False: Lentigines are "age spots" that crop up in sun exposed areas.

6. True/False: Peutz-Jeghers syndrome often is picked up when hyperpigmented macules are found on the lips of children with chronic abdominal pain.


References

1. Hurwitz S. Clinical Pediatric Dermatology, 2nd edition. 1993, Philadelphia: W.B. Saunders, pp. 242-253.

2. Silverman RA. Pediatric Dermatology. Hemangiomas and Vascular Malformations. Pediatr Clin North Am 1991;38:4811-4834.


Answers to questions

1.False, 2.True, 3.b, 4.False, 5.False, 6.True


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