Diagnóstico por imagem Aspectos dermatoscópicos do xantogranuloma juvenil com múltiplas lesões Dermoscopic aspects of juvenile xanthogranuloma with multiple lesions

Juvenile xanthogranuloma is a form of non Langerhans cell histiocytosis that mainly affects children. It usually emerges as asymptomatic yellow-brownish papules. The diagnosis is clinical and confirmed by histology. Due to its trend to involute, treatment is usually not recommended. Dermoscopy arises as a noninvasive diagnostic tool that reveals a typical pattern for this condition.


CASE REPORT
A one year-old child born and living in the city of Mogi das Cruzes (SP, Brazil), Fitspatrick's skin phototype III, presented at the consultation with a history of emergence of brownish papular lesions with onset at three months of age.The papules were asymptomatic, initially in the upper thoracic region, later on evolving to the abdomen, dorsum and face (mentum, and paranasal and preauricular regions).These lesions did not show signs of inflammation or itchiness, except for when the child accidentally traumatized them.The patient had no comorbidities or was in use of any medication, was up to date with the required vaccination, and there was no reference to similar cases in the family.The dermatological examination evidenced yellowbrownish papules with soft consistency and bosselated surface, measuring roughly 10mm in its longest diameter, located on the face (mentum, and paranasal and right preauricular regions), upper chest, dorsum and scalp's occipital region.The thoracic lesions showed a discrete yellow-orangish halo (Figures 1 and  2).There was no compromise of the patient's general condition.The dermoscopic examination allowed observing a yelloworangish color background ("setting sun" pattern), presence of delicate brownish interrupted lines (which do not constitute a pigmented network), punctate central vessels and other linear vessels disposed from the periphery to the center of the lesion, yellow-pale clouds and peripheral pigmented ring (Figures 3    and 4).After requesting an ophthalmologic evaluation, a decision was made for maintaining an expectant approach with a series of clinical follow-ups.

DISCUSSION
Juvenile xanthogranuloma (JXG) is a common form of non-Langerhans histiocytosis, arising as yellowish, sometimes pinkish asymptomatic papules, measuring between 5 and 20mm in diameter, that may become yellow-brownish in color and display telangiectasias with time. 1,3About 70% of cases arise in early childhood, 1 but children of all ages can be affected.Single lesions are more common, however children with less than six months often have multiple lesions.There is a predilection for the head and upper trunk segment.They tend to regress spontaneously around a year after the onset.Although uncommon, extra-cutaneous involvement, with lesions in the subcutaneous tissue, eyeball, liver and spleen is possible.The histological examinations of these lesions evidence a diffuse and dense pleomorphic histiocytic infiltrate, with the predominance of vacuolated cells in early stages and xanthomatous cells later on.The Touton cell (xanthomatous multinucleated, with nuclei arranged in the form of a ring is the most typical, nevertheless non-specific element of this condition. 1,2,5Dermoscopy is a useful tool in the diagnosis, in special when a decision is made for not to perform the lesion biopsy, as is the case in the present paper.2][3][4][5] In the present case, all these aspects were seen, confirming the clinical and dermoscopic diagnosis of JXG.It is possible to conclude that the dermoscopic examination provides valuable additional information for the diagnosis, 3 thus avoiding invasive procedures, such as skin biopsy, in the pediatric population.l

Figure 2 :
Figure 2: Multiple papular brownish lesions on the chest with a yellowish halo

Figure 1 :Figure 3 :
Figure 1: Yellow-brownish bosselated surface papule with soft consistency, located on the right tragus

Figure 4 :
Figure 4: Clearly identifiable "setting sun" pattern in one of the lesions, evidenced in the dermoscopic examination