Dermatology: Practical and Conceptual Letter | Dermatol Pract Concept 2019;9(2):15 155 Dermatology Practical & Conceptual Introduction There are only 4 previously published dermoscopic images of balloon cell melanoma (BCM) in the literature, 3 of primary tumors and 1 of BCM satellite metastasis. Currently, data are restricted by a low number of reports and a definitive dermo- scopic pattern of BCM is still not documented. We suggest some dermoscopic features to correctly diagnose this tumor. Case Presentation Recently, an 84-year-old Caucasian woman was referred to our skin cancer unit because of an asymptomatic nodule on the right leg for the preceding 4 months, with no personal or family history of melanoma or nonmelanoma skin cancer. Physical examination showed a well-defined, reddish nodule measuring 1 cm in diameter (Figure 1A). Dermoscopy revealed yellowish structureless areas, white lines, and irregular, hairpin-shaped and curved vessels (Figure1B). Due to suspicions of melanoma, an excisional biopsy was performed for histopathological examination. Hematoxylin and eosin (H&E) staining showed an atypical melanocytic proliferation, with an architecturally disorga- nized, predominantly intradermal component composed of cells containing hyperchromatic pleomorphic nuclei and a ballooned appearance with vacuolated cytoplasm, mitotic figures, and discrete areas of intradermal pagetoid spread (Figure 2, A and B). No ulceration, lymphovascular and peri- neural invasion, satellitosis, or regression was noted. Breslow thickness was 4.1 mm with moderate mitotic activity with 4 mitotic figures seen per square millimeter. Immunohisto- chemical staining showed positive results for melanocytic markers S100 (Figure 2C), HMB45 in the dermal component, and MELAN-A, confirming the diagnosis of BCM. Ki67 Ki67 staining was positive in balloon cells. Conclusions In 2013, the first dermoscopy report described an amelanotic nodule with a structureless yellow lesion, central ulceration, presence of terminal hairs, and curved and dotted vessels in an elderly man with a history of local trauma [1]. Balloon Cell Primary Nodular Melanoma: Dermoscopy Evidence Fernanda S. Seabra Resende1, Claudio Conforti3, Roberta Giuffrida2, Paola Corneli3, Serena Fagotti3, Ana Custrin4, Venus Shaffiei4, Iris Zalaudek3, Nicola Di Meo3 1 Department of Dermatology and Venereology, University of Brasilia, Brasilia, Brazil 2 Department of Clinical and Experimental Medicine, Section of Dermatology, University of Messina, Messina, Italy 3 Dermatology Clinic, Hospital Maggiore, University of Trieste, Trieste, Italy 4 Clinical Unit of Pathological Anatomy and Histology, University of Trieste, Trieste, Italy Key words: balloon cell, dermoscopy, histology, melanoma, oncology, dermato-oncology Citation: Resende FSS, Conforti C, Giuffrida R, Corneli P, Fagotti S, Custrin A, Shaffiei V, Zalaudek I, Di Meo N. Balloon cell primary nodular melanoma: dermoscopy evidence. Dermatol Pract Concept. 2019;9(2):155-156. DOI: https://doi.org/10.5826/dpc.0902a15 Accepted: October 31, 2018; Published: April 30, 2019 Copyright: ©2019 Resende 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. Authorship: All authors have contributed significantly to this publication. Corresponding author: Claudio Conforti, MD, Dermatology Clinic, Hospital Maggiore, Trieste, Italy. Email: claudioconforti@yahoo.com 156 Letter | Dermatol Pract Concept 2019;9(2):15 of a recent raised amelanotic nodular lesion with white lines and polymor- phous vessels in dermoscopy suggested malignancy, although the diagnosis of BCM was histologically defined. We therefore suggest focusing on 4 dermoscopic criteria during the assess- ment of a nodular lesion to rule out BCM: (1) yellowish structureless areas, (2) white lines, (3) irregular hairpin- shaped and (4) curved vessels. In 2014, a satellite metastasis of BCM was described as having a milky red structureless background, yellowish structureless areas, and a few irregu- lar, linear, hairpin-shaped, and curved vessels. As balloon cells generally lack melanin, this study proposed the asso- ciation of milky red and yellowish structureless areas as a considerable clue for the diagnosis of BCM [2]. We also reported the presence of yellowish structureless areas in our case. The dermatopathological diagnosis of BCM is reportedly challenging both careful clinical-pathological correlation as well as correctly interpreted immu- nohistochemical stains. Clinically, BCM could be presented as a nodular, ulcer- ated, polypoid, or papillomatous lesion with the absence of pigmentation. Dermoscopic evidence showed numerous aggregated white globular structures, which correspond to nests of pigmented melanocytes in the lower epidermis, papillary, and/or lower der- mis in histology. In this case the presence Figure 2. (A) H&E staining (×5) showing the radial phase of the melanoma. (B) H&E staining (×40) with cells containing hyperchromatic pleomorphic nuclei and a ballooned appearance with vacuolated cytoplasm, mitotic figures, and discrete areas of intradermal pagetoid spread. (C) Immunohistochemical staining (×2.5, S100 positive). [Copyright: ©2019 Resende et al.] A B C Figure 1. Balloon cell melanoma, clinical and dermoscopic presentation. (A) Erythematous nodule, 1 cm in diameter. (B) Yellowish structureless areas (red thick arrow), white lines (black asterisks), hairpin-shaped, and curved vessels (black arrows). [Copyright: ©2019 Re- sende et al.] A B References 1. Inskip M, Magee J, Barksdale S, Weedon D, Rosendahl C. Balloon cell melanoma in primary care practice: a case report. Der- matol Pract Concept. 2013;3(3):25-29. 2. Duman N, Sahin S, Özaygen GE, Gököz Ö. Dermoscopy of satellite metastasis of balloon cell melanoma. J Am Acad Der- matol. 2014;71(1):e11-e12.