Acta Dermato-Venereologica 99-3CompleteContent | Page 25

341 SHORT COMMUNICATION Unusual Congenital Multiple Clustered Dermatofibroma: First Reported Case on the Face Hiromi HIGAKI-MORI 1 , Yuichi YOSHIDA 1 , Masanori HISAOKA 2 , Chikako NISHIGORI 3 , Masahisa SHINDO 4 and Osamu YAMAMOTO 1 1 Department of Medicine of Sensory and Motor Organs, Division of Dermatology, Faculty of Medicine, Tottori University, 86 Nishi-Cho, Yonago, Tottori 683-8503, 2 Department of Pathology and Oncology, School of Medicine, University of Occupational and Environmental Health, 3 Division of Dermatology, Department of Internal Related, Kobe University Graduate School of Medicine, Kobe, and 4 Division of Dermatology, National Hospital Organization Hamada Medical Center, Japan. E-mail: [email protected] Accepted Dec 13, 2018; E-published Dec 13, 2018 Multiple clustered dermatofibroma (MCD) is a rare vari- ant of dermatofibroma (1). Clinically, there are multiple nodules grouped or arranged in a linear pattern on a single anatomical site, mainly in the bottom half of the body (1). We present here an unusual case of congenital MCD that developed on the face. CASE REPORT A 13-month-old boy was referred to us for examination of multiple nodules on his right forehead. The lesions were first noticed at birth and had increased during the past several months. On physical examination, firm, pink-tan nodules, ranging in size from 2 to 10 mm were clustered in a linear arrangement (Fig. 1a). Dermoscopy showed a homogenous pigment network (not shown). A biopsy specimen showed a nodular lesion in the reticular dermis and superficial subcutis (Fig. 1b). The tumour consisted of short fascicles of lightly eosinophilic spindle cells intermingled with collagen bundles (Fig. 1c). There was no significant atypia or pleomorphism in the tumour cells. The overlying epidermis showed slight acanthosis with basal hyperpigmentation. Immunohistochemistry studies showed strong positivity for alpha-smooth muscle actin (α-SMA) (Fig. 1d) and moderate positivity for factor XIIIa (Fig. 1e) and D2-40. The tumour cells were negative for CD34 (Fig. 1f), S-100 protein, SOX10, pancytokeratin (AE1/3), ERG, epithelial membrane antigen and factor VIII. Expression of trimethylation of histone H3 lysine 27 was intact. Thus, this case was diagnosed as MCD. DISCUSSION Malignant tumours, including dermatofibrosarcoma pro- tuberans (DFSP), pseudomyogenic haemangioendothe- Fig. 1. (a) Clinical appearance of nodules on the forehead. (b) Histopathological feature. The nodular lesion consisted of spindle cells in the reticular dermis and superficial subcutis (haematoxylin and eosin (HE), original magnification ×100). (c) Proliferation of spindle cells with collagen trapping (HE ×200). (d) Immunostaining for alpha-smooth muscle actin (original magnification ×200). (e) Immunostaining for factor XIIIa (×200). (f) Immunostaining for CD34 (×200). This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3109 Acta Derm Venereol 2019; 99: 341–342