Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2024;14(1):e2024070 1 Dermoscopic Features of Pilar Sheath Acanthoma Göktürk Oraloğlu1, Nilay Duman2, Banu Yaman3, Işıl Karaarslan2 1 Siirt Training and Research Hospital, Department of Dermatology, Siirt, Turkey 2 Ege University, Faculty of Medicine, Department of Dermatology, İzmir, Turkey 3 Ege University, Faculty of Medicine, Department of Pathology, İzmir, Turkey Citation: Oraloğlu G, Duman N, Yaman B, Karaarslan I. Dermoscopic Features of Pilar Sheath Acanthoma. Dermatol Pract Concept. 2024;14(1):e2024070. DOI: https://doi.org/10.5826/dpc.1401a70 Accepted: August 21, 2023; Published: January 2024 Copyright: ©2024 Oraloğlu 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: Nilay Duman, Ege University, Faculty of Medicine, Department of Dermatology, Bornova, İzmir, Turkey. Tel: + 90 (232) 390 38 30 Phax: + 90 (232) 339 97 02 E-mail: nilyduman@gmail.com; nilay.duman@ege.edu.tr Case Presentation A 65-year-old male patient presented with a 3-mm dome- shaped cribriform pinkish nodule on the back side of his right leg (Figure 1A). Dermoscopy revealed thin hairpin-like vessels on the periphery, polymorphous vessels including lin- ear curved, coiled, and hairpin vessels, and a few white clods at the center on a pinkish background (Figure 1B/C). Differ- ential diagnosis included squamous cell carcinoma, inverted follicular keratosis and melanoma. The lesion was excised and histopathological examination revealed pilar sheath acanthoma. Teaching Point Pilar sheath acanthoma (PSA) is a rare benign follicular neoplasm presented as a solitary, small, skin-colored, asymptomatic benign nodule with a central pore-like opening plugged with keratin, mostly seen in middle-aged individuals on the upper lip (1). Its non-specific clinical appearance may resemble other skin tumors such as basal cell carcinoma (2). Our case lacked a typical central pore-like opening feature clinically and revealed polymorphous vessels and white struc- tures that correlate with the fibrovascular septae at stroma surrounding the tumor histopathologically. These dermo- scopic features are non-specific and may also be observed in malignant tumors such as melanoma, metastases, and SCC. Therefore, histopathological examination remains the gold standard for diagnosing PSA. Our case findings show that PSA may have prominent vasculature on dermoscopy resem- bling malignant skin tumors. More reports are needed to de- fine the typical features of PSA in order to differentiate this tumor from other malignant tumors just by dermoscopy and thus to avoid unnecessary excisions in the future. 2 Image Letter | Dermatol Pract Concept. 2024;14(1):e2024070 References 1. Mehregan AH, Brownstein MH. Pilar sheath acanthoma. Arch Dermatol. 1978 Oct;114(10):1495-7. Figure 1. (A) 3 mm dome-shaped cribriform pinkish nodule on the back side of the right leg, (B, C) thin hairpin-like vessels on the periphery and polymorphous vessels at the center on a pinkish background and also whitish clods observed on non-polarized light (DermLite Foto System, 3Gen, San Juan Capistrano, CA, USA). 2. Jo-Velasco M, Corrales-Rodríguez A, Francés-Rodríguez L, Alegría-Landa V, Eraña-Tomás I, Rütten A, Requena L. Plaque- Like Pilar Sheath Acanthoma: Histopathologic and Immuno- histochemical Study of 3 Unusual Cases. Am J Dermatopathol. 2018 Feb;40(2):125-130.