Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2023;13(2):e2023117 1 Dermatoscopy of Bednar Tumor: New Case and Review of Literature Vincenzo Maione1, Giuseppe La Rosa1,2, Laura Miccio1,2, Claudia Zambelli3, Piergiacomo Calzavara-Pinton1,2 1 Division of Dermatology, ASST Spedali Civili di Brescia, Brescia, Italy 2 Division of Dermatology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy 3 Division of Pathology, ASST Spedali Civili di Brecia, Brescia, Italy Key words: Bednar tumor, dermoscopy, dermatofibrosarcoma, pigmeted dermatofibrosarcoma Citation: Maione V, La Rosa G, Miccio L, Zambelli C, Calzavara-Pinton P. Dermatoscopy of Bednar Tumor: New Case and Review of Literature. Dermatol Pract Concept. 2023;13(2):e2023117. DOI: https://doi.org/10.5826/dpc.1302a117 Accepted: November 23, 2023; Published: April 2023 Copyright: ©2023 Maione 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: Dr. Vincenzo Maione, Division of Dermatology, Spedali Civili, Piazzale Spedali Civili 1, Brescia, Italy. Phone +39 0303995300, Fax +39 0303995015 E-mail: maionevincenzo@gmail.com Introduction Bednar tumor is a rare variant of dermatofibrosarcoma. We report a new case with its dermatoscopic features, compar- ing them with findings of literature. Case Presentation A 14-year-old female patient presented because of the on- set of a bluish plaque on the right forearm five months be- fore (Figure 1A). Dermoscopy displayed blue-whitish areas with white streaks. A pigmented network was evident at the periphery of the lesion and in some areas appeared linearly stretched. Blurry branching vessels were distributed on the entire lesion (Figure 2). Histological exam showed a mesenchymal neoplastic pro- liferation of pigmented spindle cells, with a storiform pattern, interposed with scattered thin-walled vessels ( Figure 1B). Immunochemistry was positive for CD34+ and fluorescence in situ hybridization displayed a rearrangement of COL1A1/ PDGFB genes, confirming the diagnosis of pigmented der- matofibrosarcoma protuberans. The patient underwent sur- gical resection with wide margins and removal of the fascia. No recurrence was detected so far. Conclusions Pigmented dermatofibrosarcoma protuberans (also called Bednar Tumor), accounts for less than 5% of all dermato- fibrosarcoma protuberans (DFSP), and it is characterized by the presence of melanin-containing dendritic cells within the tumor [1]. Diagnosis is insidious, as it may be easily mistaken for other skin tumors, and for these reasons, dermoscopy can assist in the diagnosis. Classic dermatofibrosarcoma displays 6 dermatoscopic patterns: thin regular pigmented network, reticular vessels, structureless light-brown areas, white streaks, pink back- ground coloration, and structureless hypo\depigmented 2 Research Letter | Dermatol Pract Concept. 2023;13(2):e2023117 areas [2]. Only a few reports described the dermatoscopic features of its pigmented counterpart. In a study of Bernard et al among 15 patients with DFSP, only one had a histological confirmed diagnosis of Bednar tumor and displayed all six dermoscopic patterns described above [2] Meada et al reported a case of Bednar tumor in which dermoscopy displayed only blue whitish veil [3]. The same feature was present in a case of pigmented dermatofi- brosarcoma described by Ehara et al [4]. Lastly, Almeida et al described another case of Bednar tumor which showed pigmented network, whitish-blue veil, blurry branching ves- sels and white streaks as principal dermoscopic patterns [5]. The pathologic features of pigmented dermatofibrosarcoma easily correlate to these aforementioned dermatoscopic find- ings: blue-whitish veil is due to pigmented spindle cells while white streaks are caused by altered collagen fibers. Arborizing vessels, generally unfocused, may correlate with the depth of the tumor and its major need for vascularization. Moreover, peripheral pigmented network may correspond to pigmented basal keratinocytes, as in dermatofibroma. In different areas this network appeared linearly stretched and this feature could be determined by changes in the rete-ridges induced by exuberant tumor growth. Besides the potential value of each single dermoscopic criterion, the presence of all these described features could help in differentiating Bednar tumor from the other simulators as basal cell carcinoma, mel- anoma or hematoma. The diagnosis results more challenging in presence of bluish veil as unique dermatoscopic pattern. We present a case of Bednar tumor and report the pres- ence of a new dermatoscopic finding in addition to those previously reported. To confirm these assumptions further evidence is needed. Figure 1. (A) Presence of bluish indurated plaque of right arm. (B) Diffuse proliferation of spindle cells in a storiform pattern. Some cells contain abundant melanin. (H&E x4). Figure 2. (A,B) Diffuse white-bluish pigmentation associated to white streaks (black square). Arborizing vessels are present over the entire lesion and are not focused (white square). At periphery, a pigmented network is evident (black arrow). In some part of the lesion this network appears linearly stretched (black circle). Research Letter | Dermatol Pract Concept. 2023;13(2):e2023117 3 References 1. Ishida M, Okabe H. Fibrosarcomatous pigmented dermato- fibrosarcoma protuberans: A case report with review of the literature. Oncol Lett. 2012;4(3):390-392. DOI: 10.3892 /ol.2012.765. Epub 2012 Jun 19. PMID: 23741240. PMCID: PMC3673649. 2. Bernard J, Poulalhon N, Argenziano G, Debarbieux S, Dalle S, Thomas L. Dermoscopy of dermatofibrosarcoma protuberans: a study of 15 cases. Br J Dermatol. 2013;169(1):85-90. DOI: 10.1111/bjd.12318. PMID: 23496114. 3. Maeda T, Watabe Y, Yanagi T, et al. Dermoscopic features of Bed- nar tumor: Report of a case. J Dermatol. 2018;45(7):e179-e180. DOI: 10.1111/1346-8138.14232. PMID: 29341231. 4. Ehara Y, Yoshida Y, Shiomi T, Yamamoto O. Pigmented Dermato- fibrosarcoma Protuberans and Blue Naevi with Similar Dermos- copy: A Case Report. Acta Derm Venereol. 2016;96(2):272-273. DOI: 10.2340/00015555-2204. PMID: 26258458. 5. Almeida FT, Carvalho SD, Pereira T, Brito C. When a bruise gets important: Bednar tumour. BMJ Case Rep. 2019;12(2):e228446. DOI: 10.1136/bcr-2018-228446. PMID: 30755432. PMCID: PMC6381944.