Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(3):e2024175 1 Identification of Malassezia Species in Basal Cell Carcinoma Lesions by Conventional and Molecular Methods Sema Koç Yıldırım1, Fatma Nur Akdoğan Kıttana2, Sibel Ersoy Evans1, Alpaslan Alp2, Sevtap Arikan-Akdagli2, Ayşen Karaduman1 1 Department of Dermatology and Venereology, School of Medicine, Hacettepe University, Ankara, Turkey 2 Department of Medical Microbiology, School of Medicine, Hacettepe University, Ankara, Turkey Key words: Malassezia species, carcinoma, BCC Citation: Koç Yıldırım S, Akdoğan Kıttana FN, Ersoy Evans S, Alp A, Arikan-Akdagli S, Karaduman A. Identification of Malassezia Species in Basal Cell Carcinoma Lesions by Conventional and Molecular Methods. Dermatol Pract Concept. 2024;14(3):e2024175. DOI: https:// doi.org/10.5826/dpc.1403a175 Accepted: April 1, 2024; Published: July 2024 Copyright: © Koç Yıldırım 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: Supported by Hacettepe University Scientific Research Projects Coordination Unit with project number THD-2015-7168. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Dr. Sema Koç Yıldırım; Uşak University Training and Research Hospital, Department of Dermatology and Venereology, Uşak, Turkey; Tel: +90 536 7371594; E-mail: semakocyildirim@gmail.com Introduction Recent studies have suggested that aryl hydrocarbon recep- tor (AhR) activation leads to carcinogenesis in mouse skin and that polymorphism of AhR-dependent detoxification enzymes may be associated with basal cell carcinoma (BCC) pathogenesis. AhRs have many ligands with agonistic and antagonistic effects. Malassezia species synthesize ligands that can potently activate AhRs [1]. It has been hypothe- sized that the regulation of skin immunity and epidermal homeostasis induced by Malassezia may play a role in the BCC development. [2] Also, itraconazole was shown to in- hibit Hedgehog signaling pathway and reduce tumor area in BCC lesions. [3] The aim of this study was to evaluate the presence of Malassezia in BCC lesions by conventional and molecular methods. Case Presentation This cross-sectional study included 16 patients with con- firmed BCC aged ≥18 years and 13 volunteers for the control group. The samples were taken from the lesion, perilesional area, and chin of the patients by direct contact with Leeming Notman agar. The chin where there is less colonization was chosen as a control in both groups. In the control group, same regions were selected. Phenotypical identification of Malas- sezia was done according to reference criteria [4]. Nested PCR-RFLP were used to identify the colonies from culture growth and in the samples taken from the above-mentioned localizations by skin scraping. All isolates identified by phe- notypic methods were confirmed by PCR-RFLP. In patients, the most common species were M. pachy- dermatis (n=3) and M. sympodialis (n=3) in the lesions. 2 Research Letter | Dermatol Pract Concept. 2024;14(3):e2024175 The most common species were M. pachydermatis ( n=6) and M. sympodialis (n=6) in the perilesional areas. The most common species was M. slooffiae (n=5) in the chins (Table 1). M. slooffiae (n=7) was the most common type in the sam- ples taken from localizations in the controls similar to the lesions of the patients. M. slooffiae was the most common species in the chins (n=5) (Table 2). There was no statisti- cally significant difference in the rates of Malassezia species in lesional and non-lesional skin areas of the patient group. There was no significant difference between the patients and controls. In this study, the predominant species in BCCs and per- ilesional areas were M. pachydermatis and M. sympodialis. Table 1. The distribution of the Malassezia species in patient group Subject number Localization Culture/ Phenotyping and PCR-RFLP Skin scraping/ PCR-RFLP Subject number Localization Culture/ Phenotyping and PCR-RFLP Skin scraping/ PCR-RFLP P1 Nasal dorsum - - P9 Cheek M. pachydermatis - Perilesional area M. slooffiae M. furfur/ M. slooffiae Perilesional area M. pachydermatis M. pacyhdermatis/ M. restricta/ M. slooffiae Chin - - Chin M. pachydermatis - P2 Forehead - M. globose P10 Nasal dorsum M. pachydermatis - Perilesional area - M. slooffiae Perilesional area M.pachdermatis - Chin - M. furfur/ M. slooffiae/ M. pachydermatis Chin M.pachydermatis - P3 Scalp - - P11 Nasal dorsum - - Perilesional area - M. sympodialis Perilesional area M. pacyhdermatis M. pacyhdermatis Chin M. globosa - Chin - - P4 Nasal dorsum - - P12 Nasal dorsum - M. slooffiae/ M. retrictra/ M. pacyhdermatis Perilesional area M. pacyhdermatis - Perilesional area - M. sympodialis Chin M. pacyhdermatis - Chin - M. slooffiae P5 Below the lip - M. slooffiae/ M. sympodialis P13 Cheek - M.furfur Perilesional area - M. slooffiae Perilesional area - M. furfur/ M. pachydermatis/ M. obtusa Chin - M. globose/ M. slooffiae Chin M. furfur P6 Cheek - M. sympodialis P14 Below the lip M. furfur/ M. globosa - Perilesional area - M. sympodialis Perilesional area M. pacyhdermatis/ M. restricta - Chin M. pachydermatis M. pachydermatis/ M. furfur Chin - M. pacyhdermatis/ M.slooffiae P7 Lateral nose - - P15 Forehead - - Perilesional area - M. sympodialis Perilesional area - M. sympodialis Chin M. restricta M. restricta Chin M. pachydermatis/ M. slooffiae - Research Letter | Dermatol Pract Concept. 2024;14(3):e2024175 3 Table 2. The distribution of the Malassezia species in control group Subject number Localization Culture/ Phenotyping and PCR-RFLP Skin scraping/ PCR-RFLP C1 Nasal dorsum - M. slooffiae Chin M. globosa - C2 Nasal dorsum M. restricta - Chin M. globosa M. slooffiae C3 Below the lip - - Chin - M. pachydermatis C4 Nasal dorsum - M. pachydermatis Chin - - C5 Lateral nose M. furfur M. furfur Chin M. furfur M. furfur/ M. pachydermatis C6 Upper the lip - M. slooffiae Chin - M. furfur/ M. pachydermatis C7 Forehead M. furfur M. slooffiae/ M. restricta Chin M. furfur M. furfur C8 Ear helix - - Chin - M. slooffiae/ M. pachydermatis C9 Cheek - M. slooffiae Chin C10 Forehead - M. slooffiae/ M. pachydermatis Chin M. furfur/ M. pachydermatis - C11 Cheek M. slooffiae/ pachydermatis - Chin - M. restricta/ M. globosa M. / sympodialis C12 Nasal dorsum - M. slooffiae Chin M. sloffiae M. slooffiae/ M. furfur C13 Scalp - M. sympodialis Chin - - C, Control; PCR-RFLP, Polymerase chain reaction-Restriction fragment length polymorphism. Subject number Localization Culture/ Phenotyping and PCR-RFLP Skin scraping/ PCR-RFLP Subject number Localization Culture/ Phenotyping and PCR-RFLP Skin scraping/ PCR-RFLP P8 Forehead M. obtusa M. obtusa/ M. restricta P16 Ear heliks - - Perilesional area - - Perilesional area - M. globosa/ M. slooffiae/ M.sympodialis Chin - - Chin - M. sympodialis P, Patient; PCR-RFLP, Polymerase chain reaction-Restriction fragment length polymorphism. Table 1. The distribution of the Malassezia species in patient group. (continued) In the samples taken from the chins of the patients and from all localizations in the controls, the most common species was M. slooffiae. In mycobiome studies, the presence of M. pachydermatis in the nasal vestibule has been detected in healthy individuals and patients with allergic rhinitis [5]. In our study, most of the samples taken from BCCs of the patients as well as from the controls were from the nasal region. However, in nasal samples, one of the most common species was M. pachydermatis in the patients, while it was M. slooffiae in the controls. 4 Research Letter | Dermatol Pract Concept. 2024;14(3):e2024175 J Invest Dermatol. 2008;128(7):1620-1625. doi:10.1038/SJ.JID .5701252 2. Gaitanis G, Velegraki A, Magiatis P, Pappas P, Bassukas ID. Could Malassezia yeasts be implicated in skin carcinogenesis through the production of aryl-hydrocarbon receptor ligands? Med Hy- potheses. 2011;77(1):47-51. doi:10.1016/J.MEHY.2011.03.020 3. Kim DJ, Kim J, Spaunhurst K, et al. Open-label, exploratory phase II trial of oral itraconazole for the treatment of basal cell carcinoma. J Clin Oncol. 2014;32(8):745-751. doi:10.1200 /JCO.2013.49.9525 4. Identification of Malassezia species: a practical approach. pascal- francis.inist.fr. https://pascal-francis.inist.fr/vibad/index.php? action=getRecordDetail&idt=3209410. Accessed October 26, 2022. 5. Jung WH, Croll D, Cho JH, Kim YR, Lee YW. Analysis of the nasal vestibule mycobiome in patients with allergic rhinitis. Mycoses. 2015;58(3):167-172. doi:10.1111/MYC.12296 Conclusion The detection of different species in the BCC lesions that was not detected in the controls may be suggestive for studies aimed at showing whether different Malassezia species colonization play a role in the development of BCC. However, further clini- cal and molecular studies are needed to confirm this association and to prove the role of Malassezia in the pathogenesis of BCC. References 1. Gaitanis G, Magiatis P, Stathopoulou K, et al. AhR ligands, malassezin, and indolo[3,2-b]carbazole are selectively produced by Malassezia furfur strains isolated from seborrheic dermatitis.