Dermatology: Practical and Conceptual Observation | Dermatol Pract Concept 2016;6(4):11 47 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Case report A 77-year-old woman with a prior renal transplantation pre- sented with a four-month history of a progressively enlarging brownish macule on her left leg (Figure 1a). She was treated with mycophenolate mofetil and tacrolimus. Her past medical history included several non-melanoma skin cancers. Dermo- scopic examination showed atypical brownish blurry streaks regularly distributed at periphery of the lesion, simulating a “starburst” pattern; adherent white scales were present but no vessels or pigmented dots were evident (Figure 1b). A complete excision of the lesion was performed. Histological examination revealed parakeratotic hyperkeratosis with disorganization of the epidermal architecture and increased mitotic figures; kera- tinocytes with giant nuclei were associated to dyskeratotic and pigmented cells. The dermis showed a lymphohistiocytic infiltrate with absence of tumor invasion (Figure 2). Such findings were consistent with a diagnosis of pBD. Several studies/case reports have shown that pBD may present unusual/confusing dermoscopic findings [1-2], includ- ing peripheral streaks, which have been reported in four instances [1-5]. However, differently from our patient, the streak-like projections observed in the previous cases did not represent the main dermoscopic clue, as they were associ- Pigmented Bowen’s disease presenting with a “starburst” pattern Vincenzo Maione1, Enzo Errichetti3, Sara Laurent Roussel2, Celeste Lebbé1 1 Department of Dermatology, Hôpital Saint-Louis, Université Paris 7 Diderot, Paris, France. 2 Department of Pathology, Hôpital Saint-Louis, Université Paris 7 Diderot, Paris, France 3 Department of Dermatology, University of Udine, Italy Key words: dermoscopy, Bowen Citation: Maione V, Errichetti E, Roussel Sara L, Lebbé C. Pigmented Bowen’s disease presenting with a “starburst” pattern. Dermatol Pract Concept 2016;6(4):11. doi: 10.5826/dpc.0604a11 Received: July 15, 2016; Accepted: July 18, 2016; Published: October 31, 2016 Copyright: ©2016 Maione et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted 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. All authors have contributed significantly to this publication. Corresponding author: Vincenzo Maione, MD, Department of Dermatology, Hôpital Saint-Louis, 1 Avenue Claude Vellefaux, 75010 Paris, France. Tel. +33 0142499961; Fax +33 0142494620. Email: maionevincenzo@gmail.com Pigmented Bowen’s disease (pBD) is an uncommon in situ squamous cell carcinoma of the skin usu- ally presenting as a dark scaly plaque involving chronically exposed sites, which is not uncommonly mistaken for other similar pigmented lesions, such as melanoma, pigmented basal cell carcinoma or seborrheic keratosis [1,2]. Dermoscopy has been proven to improve its diagnosis by showing several findings, i.e., gray/brownish dots in linear arrangement, scales, coiled vessels, focal/multifocal amor- phous hypopigmentation and bluish structureless areas [1,2]. However, pBD may sometimes display dermoscopic features which are typical of other pigmented lesions, thus making its recognition quite troublesome despite the use of dermoscopy [1,2]. We report a case of pBD with a “starburst” pattern, discussing its dermoscopic differential diagnosis. ABSTRACT 48 Observation | Dermatol Pract Concept 2016;6(4):11 the presence of pigmented sharply focused streaks radially distributed at the periphery of a lesion, which correspond to confluent junctional melanocytic nests and histological radial growth. The detection of the “starburst” pattern in pBD might be due to the fusion of regularly distributed peripheral dots into streak-like projections, which therefore represent melanin pigment in the epidermis or horny layer [1-2]. Importantly, different from the aforementioned mela- nocytic lesions, the brownish streaks visible in pBD are less defined and appear out of focus and are associated with other features typical of Bowen’s disease [1-5], such as white scales, as seen in our patient. In conclusion, our case underlines that pBD may present with a “starburst” pattern, thereby mimicking a Spitz/Reed nevus or a melanoma. Even though the definitive distinction from these melanocytic lesions relies on histological examina- tion, we believe that an attentive analysis of the radial streaks and the search of other criteria of pBD could be useful for assisting the differential diagnosis. Further reports and studies are obviously needed to support such assumptions. References 1. Zalaudek I, Argenziano G, Leinweber B, et al. Dermoscopy of Bow- en’s disease. Br J Dermatol 2004;150:1112-6. PMID: 15214896. DOI: 10.1111/j.1365-2133.2004.05924.x. 2. Cameron A, Rosendahl C, Tschandl P, Riedl E, Kittler H. Dermos- copy of pigmented Bowen’s disease. J Am Acad Dermatol 2010; 62:597-604. PMID: 20079953. DOI: 10.1016/j.jaad.2009.06.008. ated with other relevant findings (e.g., pigmented network, polychromatic areas, blue veil and/or brown dots in a regu- lar arrangement), and were not regularly distributed at the periphery to configure a “starburst” appearance [1-7]. Conclusions The “starburst” pattern is classically considered the dermo- scopic hallmark of Spitz/Reed nevus. It is characterized by Figure 1. (a) Clinical aspect of pigmented Bowen’s disease. Brownish lesion of the left leg in a patient treated with immunosup- pressive drugs for her renal transplantation. (b) Pigmented Bowen’s disease. The dermoscopic examination showed atypical “out of focus” radial streaks (black arrow) with adherent scales (white arrow). No other dermoscopic features were present. [Copyright: ©2016 Maione et al.] Figure 2. Histologic images of Bowen’s disease showed parakera- tosis, epidermal disorganization with individual cell dyskeratosis, increased mitotic figures and keratinocytes demonstrating greatly enlarged nuclei. (Hematoxylin-eosin stain; original magnification: 20x.). [Copyright: ©2016 Maione et al.] Observation | Dermatol Pract Concept 2016;6(4):11 49 mented Bowen’s disease. An Bras Dermatol 2014;89:825-7. PMID: 25184929. 6. Chung E, Marchetti MA, Pulitzer MP, Marghoob AA. Streaks in pigmented squamous cell carcinoma in situ. J Am Acad Dermatol. 2015;72(1 Suppl): S64-5. PMID: 25500048. DOI: 10.1016/j. jaad.2014.08.044. 7. de Giorgi V1, Alfaioli B, Papi F, et al. Dermoscopy in pigmented squamous cell carcinoma. J Cutan Med Surg 2009;13(6):326-9. PMID: 19919812. 3. Hayashi Y, Tanaka M, Suzaki R, Mori N, Konohana I. Dermos- copy of pigmented Bowen’s disease mimicking early superficial spreading melanoma. Case Rep Dermatol 2009; 1:11-15. PMID: 20652107. DOI: 10.1159/000227284. 4. Inoue T, Kobayashi K, Sawada M, et al. Dermoscopic features of pigmented Bowen’s disease in a Japanese female mimicking malig- nant melanoma. Dermatol Res Pract 2010; 2010:543091. PMID: 20811602. DOI: 10.1155/2010/543091. 5. Mota AN, Piñeiro-Maceira J, Alves Mde F, Tarazona MJM. Pig-