ARTICLE
Agminated lentigines are a pigmentary disorder characterized
by multiple lentigines that are grouped within an area of normal appearing
skin [1]. Segmental lentiginosis, partial unilateral lentiginosis, and
lentiginous mosaicism are other terms used to describe this disorder.
Histologically, the pigmented macules are characterized by prominent rete
ridges of the epidermis and an increase in the melanin content of the
basal layer.
The patient reported here was suggested to have agminated lentigines from
the clinical appearance. However, histopathological examination revealed
the presence of dermal melanocytes. This report draws attention to the
careful diagnosis of segmental brown pigmented lesions of the face.
Case report
A 30-year-old Korean woman had a history of hyperpigmented macules of
the face since the age of 7 years. There was no family history of
similar pigmented lesions. The cutaneous examination revealed multiple
brown macules measuring 2 to 3 mm in diameter on the left side
of face, primarily in a V1 and V2 distribution, and right cheek (Fig. 1).
The lesions were grouped within an area of normal appearing skin. Ocular
and mucosal involvement was not noted. This clinical appearance, brown
macules in multiple segmental or grouped patterns, was suggested to be
agminated lentigines. A 2 mm punch biopsy was obtained from a macule
on the forehead. The histopathological examination of the pigmented macule
revealed scattered melanocytes within the dermis (Fig. 2).
There was no elongation of the rete ridges or increased pigmentation of
the basal layer of the epidermis. These findings were against the diagnosis
of agminated lentigines. The patient was diagnosed as bilateral type of
nevus of Ota.
Discussion
Nevus of Ota is a dermal melanocytic disease presenting as mottled blue-black
or slate-gray macules occurring in the skin innervated by the first and
second branches of the trigeminal nerve [2]. It is usually unilateral
but may appear bilaterally. When nevus of Ota occurs bilaterally like
in our patient, it can be confused with an acquired bilateral nevus of
Ota-like macules (ABNOM). ABNOM may differ from the bilateral nevus of
Ota in several points [3-5]. The acquired nature with an onset in the
fourth or fifth decades is one of the fundamental characteristics of the
ABNOM. This condition usually does not become apparent until the second
decade of life [4], while the nevus of Ota is congenital or has an
onset in the teens [5]. Thus, the early age of onset (7-year-old)
in our case favors the nevus of Ota. In addition, the asymmetric distribution
of pigmentation in our patient argues against the diagnosis of ABNOM.
This nevus shows symmetric distribution, principally in the zygomatic
region [5]. Lack of ocular pigmentation in the presented case is
against the diagnosis of nevus of Ota. However, abnormalities of ocular
pigmentation occur in 49 % to 65 % of patients with nevus of
Ota [2]. We therefore made the diagnosis of a bilateral type of nevus
of Ota because of its definite asymmetric distribution and the early age
of onset in our case.
CONCLUSION
This report draws attention to the careful diagnosis of segmental brown
pigmented lesions of face. When the distribution of dermal melanocytes
is superficial as in the present case, the nevus of Ota can be seen as
having a brownish color [6]. Dermal melanocytic disease is not improved
by the application of liquid nitrogen or conventional carbon dioxide laser
therapy, which could be useful for lentiginosis. In our experience, selective
photothermolysis with the Q-switched alexandrite laser was safe and effective
for nevus of Ota [7].
Article accepted on 13/01/03
REFERENCES
1 - Micali G, Nasca MR, Innocenzi D, Lembo D. Agminated lentiginosis;
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2 - Urabe K, Nakayama J, Hori Y, Mallory SB, Foley SA, Park YK, Hann SK,
Im S. Nevus of Ota. In: Nordlund JJ, Boissy RE, Hearing VJ, King
RA, Ortonne JP, eds. The pigmentary system. Oxford, 1998: 898-902.
3 - Hori Y, Kawashima M, Oohara K. Acquired, bilateral nevus of Ota-like
macules. J Am Acad Dermatol 1984; 10: 961-4.
4 - Sun CC, Lu YC, Lee EF, Nakagawa H. Naevus fusco-caeruleus zygomaticus.
Br J Dermatol 1987; 117: 545-53.
5 - Hidano A. Acquired, bilateral nevus of Ota-like macules J Am Acad
Dermatol 1985; 12: 368-9.
6 - Hirayama T, Suzuki T. A new classification of Ota's nevus based on
histopathological features. Dermatologica 1991; 183: 169-72.
7 - Kang WH, Lee ES, Choi GS. Treatment of Ota's nevus by Q-switched alexandrite
laser: therapeutic outcome in relation to clinical and histopathological
findings.
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