Nevus Anemicus

Transcription

Nevus Anemicus
CHAPTER
56
Nevus Anemicus
CLINICAL FEATURES
Nevus anemicus is a rare congenital functional-type vascular
malformation mostly observed in females. Clinically, the lesion
consists of a circumscribed skin area paler than the adjacent
skin. The margins of this hypochromic macula are irregular,
and satellite lesions are frequently seen close to the primary
lesion, also with the morphology of a hypochromic macula
with irregular margins but smaller than the original lesion.1–14
Although nevus anemicus arises primarily on the upper trunk
region, this vascular malformation can develop on any area of
the body surface. When the borders are subjected to diascopy,
the lesion is indistinguishable from the adjacent healthy skin.
No erythema is caused by scratching or rubbing the lesion or if
heat or cold is applied to the affected area (Figs. 56-1 to 56-3);
examination under Wood lamp confirms there is no intensification of the lesion. All these maneuvers allow clinical differentiation of nevus anemicus from other hypopigmented
macules caused by abnormalities of melanin pigmentation, for
example, vitiligo, nevus achromicus, or hypochromic macules
from tuberous sclerosis. Frequently, nevus anemicus is one of
the components of phakomatosis pigmentovascularis types II,
III, and IV.5,9,12,14
Some skin lesions with a persistent pale purple erythematous
area have been described. The appearance of these lesions is due
to an increase of the vasoconstrictor tone in the thermoregulatory vessels, which leads to relative ectasia of the most superficial
vessels of the dermis in the affected area. These lesions, called
nevus oligemicus, are considered variants of nevus anemicus.8
FIGURE 56-2. Nevus anemicus on the anterior abdominal wall.
Another variant of nevus anemicus described by Miura et al.15 is
characterized by the presence of multiple hypochromic macules
involving the arms. However, Plantin et al.16 considered these
lesions to be an exaggerated expression of the physiologic dotted whitening of the limbs present in some healthy people due
to changes of the vascular tone, and, according to the authors,
this would not qualify as true nevus anemicus.
Usually, nevus anemicus is an isolated malformation, although
cases associated with neurofibromatosis type I, nevus flammeus,
Sturge-Weber syndrome, nevus spilus, primary lymphedema,
alopecia universalis, onychodystrophy, generalized vitiligo,
atopic dermatitis, and ipsilateral ocular melanosis have been
described.17–19
HISTOPATHOLOGIC CHARACTERISTICS
FIGURE 56-1. Nevus anemicus on the upper part of the back.
Nevus anemicus is a functional-type, not anatomical, vascular
malformation. Thus, histopathologic, immunohistochemical,
and ultrastructural studies have not been able to show any
structural abnormality in the blood vessels of the affected skin.1
However, intralesional injections of vasodilating substances
such as bradykinin, pilocarpine, acetylcholine, 5-hydroxytryptamine, nicotine, or histamine do not cause vasodilatation or
erythema in the skin area affected by a nevus anemicus.1 On
the other hand, erythema does develop if an axillary sympathectomy has previously been performed1 or with an intralesional
injection of an alpha-adrenergic a­ ntagonist.2,3 Thus, it seems
that nevus anemicus is the result of permanent ­vasoconstriction
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SECTION 3 | VASCULAR TUMORS
FIGURE 56-3. A: Nevus anemicus involving the skin of the right breast in a middle-aged woman. B: Friction to the area causes perilesional
erythema, but the anemic nevus remains hypochromic.
due to regulatory disorders of the adrenergic receptors in the
blood vessels walls in the affected area.6,7 Furthermore, it has
been shown that the blood vessels in the skin affected by a
nevus anemicus do not show the normal physiologic response
to proinflammatory cytokines, at least regarding E-selectin
expression. On the other hand, if a contact dermatitis ­develops
in a skin area that has previously been affected by a nevus
anemicus, no expression of intercellular adhesion molecule-1
(ICAM-1) or human leukocyte antigen-DR (HLA-DR) is seen
in the epidermal keratinocytes of the affected area, which is
probably due to the absence of infiltrating lymphocytes.11 All
these findings support the notion that nevus anemicus is the
result of a local increase of catecholamine-induced vascular
reactivity. Autologous transplantation reveals predominance
of the donor area, that is, the transplantation of lesional skin
to an area of healthy skin reproduces the lesion in the recipient skin area. This further supports the idea that the anemic
nevus is caused by increased susceptibility to vasoconstrictor
stimuli or a decreased blood vessel response capacity towards
vasodilatory stimuli in the affected skin.2 The lesions known
as vascular twin nevi refer to a telangiectatic nevus and a nevus
anemicus occurring simultaneously in the same patient in
adjacent skin areas and are interpreted as allelic expressions of
somatic mutations.10
TREATMENT
Nevus anemicus usually requires no treatment. If the patient
wants to camouflage the lesion for cosmetic reasons, a tinted
cream is usually sufficient.
REFERENCES
1. Greaves MW, Birkett D, Johson C. Nevus anemicus: a unique catecholaminedependent nevus. Arch Dermatol. 1970;102:172–176.
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2. Daniel RH, Hubler WR, Wolf JE, et al. Nevus anemicus: donor-dominant
defect. Arch Dermatol. 1977;113:53–56.
3. Mountcastle EA, Diestelmeier RM, Lupton GP. Nevus anemicus. J Am
Acad Dermatol. 1986;14:628–632.
4. Fleischer TL, Zeligman I. Nevus anemicus. Arch Dermatol. 1969;100:
750–755.
5. Ratz JL, Roenigk HH Jr. Multiple vascular anomalies: report of a case.
J Dermatol Surg Oncol. 1978;4:684–686.
6. Raff M. Die Bedeutung adrenerger Rezeptoren für die Entstehung des
Naevus flammeus und des Naevus anaemicus. Wien Klin Wochenschr.
1981;129(suppl):1–14.
7. Dupre A, Bonafe JL, Jouas H. Naevus anemique generalise acquis.
Dermatologica. 1981;163:276–281.
8. Davies MG, Greaves MW, Coutss A, et al. Nevus oligemicus. A variant of
nevus anemicus. Arch Dermatol. 1981;117:111–113.
9. Hidano A, Arai Y. Hemihypertrophie congenitale associee a des anomalies
cutanees pigmento-vasculaires, cerebrales, viscerales et squelettiques. Ann
Dermatol Venereol. 1987;114:665–669.
10. Happle R. Allelic somatic mutations may explain vascular twin nevi. Hum
Genet. 1991;86:321–323.
11. Mizutani H, Ohyanagi S, Umeda Y, et al. Loss of cutaneous delayed
hypersensitivity reactions in nevus anemicus. Evidence for close concordance of cutaneous delayed hypersensitivity and endothelial E-selectin
expression. Arch Dermatol. 1997;133:617–620.
12. Di Landro A, Tadini GL, Marchesi L, et al. Phakomatosis pigmentovascularis: A new case with renal angiomas and some considerations about the
classification. Pediatr Dermatol. 1999;16:25–30.
13. Ahkami RN, Schwartz RA. Nevus anemicus. Dermatology. 1999;198:
327–329.
14. Hasegawa Y, Yasuhara M. Phakomatosis pigmentovascularis type IVa.
Arch Dermatol. 1985;121:651–655.
15. Miura Y, Tajima S, Ishibashi A, et al. Multiple anemic macules on the
arms: a variant form of nevus anemicus? Dermatology. 2000;201:180–183.
16. Plantin P, Schoenlaub P. Multiple anemic macules on the arms: not a variant form of nevus anemicus. Dermatology. 2001;202:271–272.
17. Katugampola GA, Lanigan SW. The clinical spectrum of naevus anaemicus and its association with port wine stains: report of 15 cases and a
review of the literature. Br J Dermatol. 1996;134:292–295.
18. Hernández-Núñez A, Borbujo J, Córdoba S, et al. Nevus anemicus of the
cheek with ipsilateral melanosis bulbi: an unusual example of didymosis.
Eur J Dermatol. 2011;21:597–598.
19. Del Pozo J, Gómez-Tellado M, López-Gutiérrez JC. Malformaciones
vasculares en la infancia. Actas Dermo-Sifilograficas. 2012;103:661–678.
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