Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(4):e2024236 1 Non-invasive Imaging Techniques for the Diagnosis of Chromoblastomycosis Giulio Cortonesi1, Davide Cosetti1, Mariano Suppa2, Cyril Habougit3, Jean-Luc Perrot4, Elisa Cinotti1 1 Dermatology Unit, Department of Medical, Surgical, and Neurological Sciences, Santa Maria Alle Scotte Hospital, Siena, Italy 2 Department of Dermatology, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium 3 Department of Pathology, University Hospital of Saint-Etienne, Saint-Etienne, France 4 Department of Dermatology, University Hospital of Saint-Etienne, Saint-Etienne, France Key words: Chromoblastomycosis, Confocal reflectance microscopy, Line-filed confocal optical coherence tomography, Dermoscopy Citation: Cortonesi G, Cosetti D, Suppa M, Habougit, Perrot JL, Cinotti E. Non-invasive Imaging Techniques for the Diagnosis of Chromoblastomycosis. Dermatol Pract Concept. 2024;14(4):e2024236. DOI: https://doi.org/10.5826/dpc.1404a236 Accepted: July 14, 2024; Published: October 2024 Copyright: ©2024 Cortonesi 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: Giulio Cortonesi, MD, Dermatology Section, Santa Maria alle Scotte Hospital, Viale Mario Bracci, 53100, Siena, Italy. E-mail: giuliocortonesi@gmail.com Introduction Chromoblastomycosis is a fungal infection that results from traumatic implantation of dematiaceous fungi through the skin [1]. It manifests clinically as oligosymptomatic or as- ymptomatic skin lesions, which would explain why patients only tend to seek medical care after months or even years of living with the disease. Other common presentations include tumoral, cicatricial and sporotrichoid forms [1]. Direct mi- croscopy proves the presence of 5-12 μm sized thick-walled dark-colored structures called Medlar bodies. Histopathol- ogy shows pseudoepitheliomatous hyperplasia with intraepi- dermal abscess and Medlar bodies [2]. Case Presentation A young girl presented with a facial erythematous scaly plaque with central clearing that had been present for three months (Figure 1A). Dermoscopy at ×20 (Medicam 1000, Fotofinder System) showed dilated hyperkeratotic hair fol- licles and tiny brown dots (Figure 1B) that were better visi- ble at ×400 (Fotofinder Medicam 1000, Fotofinder System; Figure 1C). Reflectance confocal microscopy ([RCM] VivaScope 3000; Figure 2B) and line-field confocal opti- cal coherence tomography ([LC-OCT]; Figure 2, C-E) re- vealed enlarged hair follicles and multiple hyperreflective roundish structures in the superficial dermis. RCM also 2 Research Letter | Dermatol Pract Concept. 2024;14(4):e2024236 (Figure 2A). Direct microscopy proved the presence of fun- gal structures suggestive of chromoblastomycosis. Itracon- azole 200 mg/day for six months was prescribed, with complete response. Discussion Dermoscopic features have been reported in few cases as white areas corresponding to hyperkeratosis, orange areas corresponding to a granulomatous infiltrate, and reddish black dots and globules related to hemorrhage and the transepidermal elimination of fungal elements. Widespread brown dots seen in our case have also been described (sand-like pattern), and we hypothesized that they could correspond to fungal elements within the pap- illary dermis. We highlight that super-high magnification dermoscopy at ×400 can better indicate these structures, which are barely visible at ×20 dermoscopy, as has already been reported in other pigmented mycosis. Moreover, hair follicle hyperkeratosis was an additional feature in our case, possibly due to the facial site. RCM and LC-OCT are recent noninvasive imaging techniques that can be used to help to diagnose some skin infections. In our case, we observed with both techniques diffused clearly visible hyperreflective roundish bodies that could correspond to melanosome and fungal structures and could explain the dots seen at dermoscopy. This description was confirmed by other previous studies, where bright white spherical bodies was observed e related to fungal infection [3]. High-frequency ultrasonography allowed identification of the presence of epidermal thickening and well-defined hyperechogenic round structures in the epidermis and in the superficial dermis, which histopathology described as a granulomatous infiltrate with giant cells surrounding pigmented spherical fungal structures [4]. Conclusion In conclusion, ×400 dermoscopy, RCM, and LC-OCT repre- sent new imaging techniques that can be used as innovative tools for the diagnosis and for the monitoring of skin tumors and infectious and inflammatory diseases [5,6]. In this case, they were useful for the diagnosis of chromoblastomycosis through the identification of the possible presence of the fungal elements. Figure 1. (A) Clinical, (B) dermoscopic, and (C) dermoscopy ×400 images. found numerous hyperreflective dendritic cells inside the epidermis and the hair follicle epithelium. Histopathol- ogy demonstrated a granulomatous dermal infiltrate ap- pearance with giant cells resorbing exogenous material Research Letter | Dermatol Pract Concept. 2024;14(4):e2024236 3 References 1. Brito AC, Bittencourt MJS. Chromoblastomycosis: an etio- logical, epidemiological, clinical, diagnostic, and treatment update. An Bras Dermatol. 2018 Jul-Aug;93(4):495-506. DOI: 10.1590/abd1806-4841.20187321. PMID: 30066754; PMCID: PMC6063100. 2. Uribe F, Zuluaga AI, Leon W, Restrepo A. Histopathology of chromoblastomycosis. Mycopathologia. 1989 Jan;105(1):1-6. DOI: 10.1007/BF00443822. PMID: 2739689. 3. Borges JR, Lacarrubba F, de Paula HM, Ianhez M, Garcia-Zapata MTA. In-vivo reflectance confocal microscopy in patients with chromoblastomycosis. Int J Infect Dis. 2021 Dec;113:297-299. DOI: 10.1016/j.ijid.2021.09.030. Epub 2021 Sep 20. PMID: 34547491. 4. Giraldelli GA, Baka JLCS, Orofino-Costa R, Piñeiro-Maceira J, Barcaui E, Barcaui CB. In vivo reflectance confocal microscopy, dermoscopy, high-frequency ultrasonography, and histopa- thology features in a case of chromoblastomycosis. PLoS Negl Trop Dis. 2022 Mar 3;16(3):e0010226. DOI: 10.1371/journal. pntd.0010226. PMID: 35239668; PMCID: PMC8893326. 5. Campoli M, Cortonesi G, Tognetti L, Rubegni P, Cinotti E. Noninvasive imaging techniques for the diagnosis of cutane- ous larva migrans. Skin Res Technol. 2022 Mar;28(2):374-376. DOI: 10.1111/srt.13126. Epub 2021 Dec 19. PMID: 34923675; PMCID: PMC9907695. 6. Cinotti E, Cioppa V, Tognetti L, et al. Super-High Magnifica- tion Dermoscopy in 190 Clinically Atypical Pigmented Lesions. Diagnostics (Basel). 2023 Jun 30;13(13):2238. DOI: 10.3390/ diagnostics13132238. PMID: 37443632; PMCID: PMC10340569. Figure 2. (A) Histological, (B) reflectance confocal microscopy (RCM), and (C-E) line-field confocal optical co- herence tomography (LC-OCT) images. Both RCM and LC-OCT show hyperreflective roundish structures in the superficial dermis suggestive of fungal structures.