Dermatology: Practical and Conceptual Letter | Dermatol Pract Concept 2020;10(4):2020084 1 Dermatology Practical & Conceptual Introduction Cutaneous angiosarcoma (cAS) is an aggressive mesenchy- mal neoplasm of vascular endothelial cells that typically presents in middle-aged to elderly individuals as an expand- ing ecchymotic patch on the head or neck region [1]. As more dermoscopic features of uncommon skin tumors are described in the literature, the importance of establishing specific criteria for the diagnosis of high-risk lesions is para- mount. In this article, we delineate the dermoscopic features of cAS and their correlation to its histopathologic findings. Case Presentation Our patient is a 74-year-old man who presented to the clinic with a 2-month history of a red-purple and yellow-black patch on his left periorbital skin expanding to involve his left forehead, frontal, temporal, and parietal scalp (Figure 1). Palpable edema was appreciated periorbitally. A punch biopsy was performed and demonstrated a high-grade in- Purpuric Plaques—Dermoscopic and Histopathological Correlation of Cutaneous Angiosarcoma Daniel W. Cole1, Tomas Huerta2, Aleodor Andea2,3, Trilokraj Tejasvi2 1 Wayne State University School of Medicine, Detroit, MI, USA 2 Department of Dermatology, University of Michigan, Ann Arbor, MI, USA 3 Department of Pathology, University of Michigan, Ann Arbor, MI, USA Key words: cutaneous angiosarcoma, dermoscopy, nonmelanocytic skin cancer, histopathology Citation: Cole DW, Huerta T, Andea A, Tejasvi T. Purpuric plaques—dermoscopic and histopathological correlation of cutaneous angiosarcoma. Dermatol Pract Concept. 2020;10(4):e2020084. DOI: https://doi.org/10.5826/dpc.1004a84 Accepted: May 16, 2020; Published: October 26, 2020 Copyright: ©2020 Cole et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License BY- NC-4.0, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. Authorship: All authors have contributed significantly to this publication. Corresponding author: Daniel W. Cole, BS, Wayne State University School of Medicine, 540 E Canfield St, Detroit, MI 48201, USA. Email: dcole@med.wayne.edu Figure 1. Exam showed a red-purple and yellow-black patch on the left periorbital skin that expanded to involve the left forehead, frontal, temporal, and parietal scalp. 2 Letter | Dermatol Pract Concept 2020;10(4):2020084 filtrative vascular neoplasm involving the dermis consistent with a diagnosis of angiosarcoma (Figure 2). CD31 and ERG immunohistochemical stains highlighted the atypical endo- thelial cells confirming the diagnosis. The dermoscopy image from our patient demonstrated dark red and purple structureless zones on a light red back- ground. A violaceous hue was also observed in more densely covered areas (Figure 3). There were thick white, perpendic- ular, and polygonal lines scattered throughout. Centrally we noted many dark red and purple dots and clods clustered around follicular openings, which appeared as white and yellow circles. This observation is a unique pattern in cAS. Interpreted in conjunction with the histopathologic images (Figure 2), the perifollicular clods represent vascular chan- nels that remarkably spare pilosebaceous units despite the infiltrative, aggressive nature of these tumors. The varying color gradations correlate with the position of the vascular structures in the dermis, with superficial dermal vascular structures appearing red to dark red, and deeper dermal in- volvement (nearly to the level of the subcutis) imparting a violaceous hue to the lesion. Figure 2. Punch biopsy. (A) Lower power view of tumor architecture sparing pilosebaceous units. (B) Infiltrative vascular neoplasm involving the dermis and extending to the peripheral margin. (C) Irregular interanastomosing vascular channels lined by atypical endothelial cells. (D) Immunohistochemical stain for ERG highlights the atypical endothelial cells. (E) Immunohistochemical stain for CD31 highlights the atypical endothelial cells. A B C D E Figure 3. Dermoscopy demonstrating dark red and purple struc- tureless zones on a light red background with a violaceous hue seen in more densely covered areas. Dark red and purple clods are clus- tered around follicular openings that appear as yellow and white circles. Thick, polygonal and perpendicular white lines are scattered throughout. Letter | Dermatol Pract Concept 2020;10(4):2020084 3 of many dark red and purple clods surrounding follicular openings, along with previously described features and a suggestive history, should prompt high clinical suspicion of cAS and histopathologic evaluation. References 1. Oiso N, Matsuda H, Kawada A. Various colour gradations as a dermatoscopic feature of cutaneous angiosarcoma of the scalp. Australas J Dermatol. 2013;54(1):36-38. DOI: 10.1111/j.1440- 0960.2012.00885.x. PMID: 22458422. 2. Deinlein T, Richtig G, Schwab C, et al. The use of dermatoscopy in diagnosis and therapy of nonmelanocytic skin cancer. J Dtsch Dermatol Ges. 2016;14(2): 144-151. DOI: 10.1111/ ddg.12903. PMID: 26819109. Conclusions In previous reports, cAS is dermoscopically characterized by structureless, patchy pink, red, and purple-blue areas with yellowish round clods corresponding to follicular openings [2]. These color gradations represent various tumor compo- nents: pink areas are highly cellular, red polymorphic areas consist of telangiectasias or vascular channels, and dark red to purple areas may be organizing thrombus, hemorrhage, or dilated vascular structures [1]. Additionally, white lines may be present within these areas or at the periphery of nodular foci and are histopathologically correlated to fibrous septa be- tween neoplastic vascular spaces [2]. The perifollicular clods observed in our patient represent tumor vascular channels. Although rare, the aggressive nature of this malignancy underscores the importance of early diagnosis. The presence