10.5826/dpc.1302a137
text/xml
2160-9381
2880
en
Cristian Patricio Navarrete-Dechent
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
diagnosis
Visualizing Touton Giant Cells Under Reflectance Confocal Microscopy in Two Cases of Juvenile Xanthogranuloma
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2023-04-29
2022-09-28
2023-04-29
2023-06-05
e2023137
Dermatol Pract Concept
Cristian Patricio Navarrete-Dechent
2023/04/29
10.5826/dpc.1302a137
e2023137
Department of Dermatology, Facultad de Medicina, Pontificia Universidad Católica de Chile
2160-9381
diagnosis
en
e2023137
Pimenta R, Leal-Filipe P, Oliveira A. Reflectance confocal microscopy for the noninvasive diagnosis of cutaneous juvenile xanthogranuloma. Skin Res Technol. 2019;25(1):106-107. DOI: 10.1111/srt.12616. PMID: 30019531.
Visualizing Touton Giant Cells Under Reflectance Confocal Microscopy in Two Cases of Juvenile Xanthogranuloma
https://dpcj.org/index.php/dpc/article/download/2880/2084
    Visualizing Touton Giant Cells Under Reflectance
          Confocal Microscopy in Two Cases of
               Juvenile Xanthogranuloma
Dominga Peirano1, Francisca Donoso1, Sebastián Vargas1, Leonel Hidalgo1, Teo Feuerhake2,
            Alon Scope3,4, Caterina Longo5,6, Cristian Navarrete-Dechent1,7


1 Department of Dermatology, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
2 Department of Pathology, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
3 The Kittner Skin Cancer Screening & Research Institute, Sheba Medical Center, Ramat Gan, Israel
4 Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
5 Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy
6 Centro Oncologico ad Alta Tecnologia Diagnostica-Dermatologia, Arcispedale Santa Maria Nuova, Azienda Unità Sanitaria Locale - IRCCS
  Reggio Emilia, Reggio Emilia, Italy
7 Melanoma and Skin Cancer Unit, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile



Key words: confocal microscopy, Touton cells, diagnosis, juvenile xanthogranuloma
Citation: Peirano D, Donoso F, Vargas S, et al. Visualizing Touton Giant Cells Under Reflectance Confocal Microscopy in Two Cases of
Juvenile Xanthogranuloma. Dermatol Pract Concept. 2023;13(2):e2023137. DOI: https://doi.org/10.5826/dpc.1302a137
Accepted: November 28, 2022; Published: April 2023
Copyright: ©2023 Peirano et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use,
distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing Interests: None.
Authorship: All authors have contributed significantly to this publication.
Corresponding Author: Cristian Navarrete-Dechent, MD, IFAAD, Department of Dermatology, Escuela de Medicina, Pontificia Universidad
Católica de Chile Diagonal Paraguay 362, 6th floor Santiago, Chile. 8330077 Phone: +56-2-2435 3574 E-mail: ctnavarr@gmail.com




Introduction                                                             microscopy (RCM) is a non-invasive optical imaging tool
                                                                         that allows for in vivo visualization of skin at cellular-level
Juvenile xanthogranuloma (JXG) is a benign non-­Langerhans​              resolution [4]. Herein, we report that an infiltrate of Touton
-cell histiocytosis occurring most frequently in childhood [1].          giant cells, a key criterion for diagnosis of JXG, can be read-
As JXG is rare in adults, it may clinically simulate malignant           ily identified via RCM.
skin tumors, such as basal cell carcinoma (BCC) or amela-
notic melanoma [2].
    Histopathologically, JXG is characterized by a granu-
                                                                         Case Presentation
lomatous inflammation pattern, whereby the dermal infil-
trate consists of histiocytes with abundant cytoplasm and of             Case 1. A 63-year-old female was referred for evaluation of
Touton giant cells with a ring-like arrangement of multiple              a long-standing lesion on the back. On physical examina-
nuclei, separating a central eosinophilic area from the pe-              tion, a 4-mm orange-pink papule was seen (Figure 1A). On
ripheral foamy and pale cytoplasm [3]. Reflectance confocal              ­dermoscopy, the lesion showed a red-yellow center and discrete



Research Letter | Dermatol Pract Concept. 2023;13(2):e2023137                                                                          1
 Figure 1. Juvenile xanthogranuloma. A. 4-mm orange-pink papule B. Dermoscopy showed a red-yellow center and discrete erythematous
 halo (‘setting-sun appearance’) (polarized light dermoscopy, original magnification 10x). C. On reflectance confocal microscopy (RCM), a
 disarranged dermal-epidermal junction was seen, filled with clusters of roundish, large, cells. These were large cells (40-50 microns largest
 diameter) with a hyperrefractile cytoplasm forming a peripheral rim and a large hypo-reflective nucleus, suggestive of Touton cells (yellow
 arrow). Horizontal blood vessels were also seen (red arrows) (0.5 x 0.5 mm, 30x) D. Large cells seen on RCM corresponded to the Touton
 cells seen on histopathology (yellow arrows), blood vessels (red arrow) and foamy histiocytes (blue arrows) (H&E, 40x).



erythematous halo (“setting-sun appearance”) (Figure 1B).                When performing a side-by-side RCM to histopathologi-
On RCM, at the superficial dermis level, an infiltrate of round-         cal correlation, it became clear that the roundish large cells
ish large cells was seen. These were characterized by a hyper-re-        under RCM corresponded to the Touton giant cells seen on
fractile peripheral rim and a hypo-reflective center, measuring          histopathology.
40-50 microns in diameter, suggestive of Touton cells (Figure                Case 2. A 13-year-old healthy boy was referred for evalua-
1C). A punch excision of the lesion showed a dense dermal in-            tion of a solitary pink-yellow lesion on the left arm (Figure 2A).
filtrate of histiocytes. At higher magnification, multinucleated         Dermoscopy revealed homogeneous yellow color (Figure 2B).
giant cells with nuclei surrounding a central homogeneous cy-            On RCM, a dense infiltrate of roundish, large cells with dark
toplasm measuring 30-50 microns corresponding with Touton                center, surrounded by a hyper-refractile peripheral ring, were
giant cells, were seen. Foamy histiocytes were also visualized           visualized (Figure 2C). The lesion was excised and diagnosed
(Figure 1D). These findings pointed to the diagnosis of JXG.             histopathologically as XGJ (Figure 2D).



2                                                                             Research Letter | Dermatol Pract Concept. 2023;13(2):e2023137
 Figure 2. Juvenile xanthogranuloma. A. A solitary pink-yellow lesion on the left arm B. On dermoscopy, a homogeneous yellow color
 was seen (polarized light dermoscopy, original magnification 10x) C. Reflectance confocal microscopy shows dilated dermal papillae at
 dermal-epidermal junction filled with clusters of roundish, large, multinucleated and hyper-refractile atypical cells corresponding to Tou-
 ton cells (yellow arrows) (0.5 x 0.5 mm, 30x). D. Histopathology showed a dense histiocytic infiltrate with Touton cells (yellow arrows)
 and foamy histiocytes (blue arrows) (H&E, 40x).




Conclusions                                                             both cases. As the identification of Touton giant cells is a key
                                                                        diagnostic finding in JXG, these cases highlight the potential
JXG is a benign disease, mostly presenting as a solitary pap-           for the bedside diagnosis of JXG with the aid RCM [4,5].
ule or nodule in childhood. We present two cases of JXG, in
an adult and in a child, whereby RCM revealed large round-
ish cells with hypo-reflective center and surrounding hy-               References
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Research Letter | Dermatol Pract Concept. 2023;13(2):e2023137                                                                              3
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