Phacomatosis pigmentovasculosebacea: an unusual case of phacomatosis multiplex

ARTICLE

Auteur(s) : WenChieh CHEN¹, Rudolf HAPPLE²

¹ Department of Dermatology, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, 704 Tainan, Taiwan.
² Rudolf Happle: Department of Dermatology, University of Marburg, Deutschhausstr. 9, 35033 Marburg, Germany

Article accepted 11/2/2003

Phacomatosis, originally used by clinicians to refer to a quite heterogenous group of diseases involving both the skin and the brain, is nowadays considered inappropriate for the classification of neurocutaneous diseases [1]. This term, however, may be applied, together with a specifying adjective, to some genetically determined diseases characterized by the presence of multiple nevi with or without systemic involvement, such as phacomatosis pigmentovascularis or phacomatosis pigmentokeratotica [1]. Phacomatosis pigmentovascularis, first described by Ota et al in 1947 [2], is characterized by coexisting melanocytic and vascular nevi and has been further classified into 4 subtypes [3]. Phacomatosis pigmentokeratotica, as proposed by Happle et al, is distinguished by the presence of a sebaceous nevus and a contralateral or ipsilateral speckled lentiginous nevus [4]. Here we report an unusual case showing a combination of nevus fuscocoeruleus, large café-au-lait macules, nevus achromicus, telangiectatic nevus and systematized sebaceous nevus. We propose the term “phacomatosis pigmentovasculosebacea” to describe this unusual concurrence of pigmentary, vascular and epithelial nevi.

Case report

A 13-year-old Taiwanese boy presented to our department with the following skin lesions that had been noted at birth or soon afterwards: (1) blue-black macules on the left side of the back and the lumbar region as well as on the dorsal aspect of the right wrist arranged in a linear configuration (nevus fuscocoeruleus) (Fig. 1a) [2] large, uniformly dark brown macules with a serrated or irregular margin, involving the posterior aspect of right thigh and anterior knee (Fig. 2a), [3] confluent hypopigmented macules involving the right side of the back with irregular margins, which turned to red after rubbing (nevus achromicus) (Fig. 1b), [4] unilateral wide-spread deep red or purple-red macules (nevus flammeus) involving the left buttock and continuing to the medial aspect of the thigh, the calf, the fibular half of sole and the 3^rd, 4^th and 5^th toes (Fig. 2b), [5] multiple, pale-pink telangiectatic macules on the right upper part of the back (Fig. 1c), [6] a circumscribed, hairless verrucous plaque of orange-yellow color over right parietal scalp with linear, slightly raised, verrucous lesions on the neck (nevus sebaceus) (Fig. 2c). The patient is otherwise in good general health with normal mental development. Further examination including neurological and ophthalmological and visceral checkup did not show any additional anomalies. The family history is noncontributory. Histopathological examination including immunostaining with monoclonal antibody S100A1 protein (Glostrup, Denmark) of the pigmentary lesions as shown in Fig. 2a showed increased amounts of melanin in the basal cell layer without any augmentation of cellular components.

Discussion

As compared to previously described cases of phacomatosis pigmentovascularis, the present case is exceptional because of the multitude of different nevi including nevus fuscocoeruleus, large nevi showing café-au-lait hyperpigmentation, nevus achromicus, nevus flammeus as well as telangiectatic nevi of a pale-pink type, and systematized sebaceous nevus.
Differential diagnosis of the uncharacterized macular hyperpigmentation might include café-au-lait spots of neurofibromatosis, the hyperpigmented macules of McCune-Albright syndrome, Becker’s nevus and nevus spilus. Unusual for Becker’s nevus would be the visibility at birth. The absence of speckled, darkly pigmented nevomelanocytic elements rules out the diagnosis of nevus spilus (speckled lentiginous nevus) [5]. The large solitary, dark brown patch was reminiscent of the macular hyperpigmentation as seen in McCune-Albright syndrome, but the patient does not have any bone lesions and endocrine dysfunction. With regard to the hypopigmented area, its close proximity to the telangiectatic macules suggested, at a first glance, the presence of vascular twin nevi in the form of nevus telangiectaticus and nevus anemicus [6]. However, the induction of erythema in the hypopigmented area after friction rules out nevus anemicus. The congenital segmental hypopigmentation in off-white color with irregular, serrated, feathered or “geographic” margins is characteristic of nevus achromicus, rather than of vitiligo or postinflammatory hypomelanosis [7].
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Finally the associated sebaceous nevus shows a systematized linear involvement of the head and neck [8].
The coexistence of more than 4 different types of birthmarks derived from three different cell types (melanocytic, epidermal, vascular) in the same patient may be best explained as a complex form of twin spotting [9]. If so, our case would provide further evidence that twin spotting may have both allelic and non-allelic components and that somatic recombination may involve three or four mutations at multiple loci at the same time [6,10]. Unlike most of the reported cases of phacomatosis pigmentovascularis [3], the various nevi of our patient were not in close proximity to each other, but rather involved the entire body.
The naming of our case based on the current classification systems is rather difficult. The coexistence of nevus flammeus and aberrant nevus fuscocoeruleus would correspond to the type 2 of phacomatosis pigmentovascularis that represents the most commonly reported form. However, the presence of a systematized sebaceous nevus along with different nevi derived from the melanocytic system in our case is at variance with this classification. A similar combination of nevus sebaceus with nevus flammeus, nevus achromicus and café-au-lait macules was not found in our review of the literature. The pigmentary component in the classical cases of phacomatosis pigmentovascularis consists of either nevus fuscocoeruleus (“type 2”) or speckled lentiginous nevus (“type 3”). The “paired light brown melanotic and achromic macules” in a case reported by de las Heras et al represent a distinctly different pigmentary component [10]. Analogously, the nevus achromicus of our patient may be an allelic counter-part of the epidermal hypermelanosis.
For the present case we propose the provisional term phacomatosis pigmentovasculosebacea to encompass the unusual combination of pigmentary, vascular and sebaceous components that are usually found in cases of phacomatosis pigmentovascularis and phacomatosis pigmentokeratotica. Theoretically, other unusual combinations of the different allelic and non-allelic components may be identified in the future. n

Acknowledgements. The authors gratefully acknowledge the histopathological assessment by Prof. J Y-Y Lee, Department of Dermatology, National Cheng Kung University, Tainan, Taiwan.

References

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7. Mosher DB, Fitzpatrick TB, Ortonne J-P, Hori Y. Hypomelanoses and hypermelanoses. In: Freedberg IM et al., eds. Fitzpatrick’s dermatology in general medicine. 5th ed. New York: McGraw-Hill, 1999: 945-1017.

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10. de las Heras E, Boixeda JP, Ledo A, Happle R. Paired melanotic and achromic macules in a case of phacomatosis pigmentovascularis: a further example of twin spotting ? Am J Med Genet 1997; 70: 336-7.