Acta Dermato-Venereologica 99-10CompleteContent | Page 23

915 SHORT COMMUNICATION Cellular Angiofibroma: Case Report of a Unique Subungual Presentation Christophe PERRIN 1 , Giuseppe E. CANNATA 2 , Florence PEDEUTOUR 3 , Bérengère DADONE-MONTAUDIÉ 1,3# and Damien AMBROSETTI 1# Central Laboratory of Pathology, Nice University Hospital, 30, Avenue Voie Romaine- CS 51069, FR-06001 Nice, Cedex 1, France, 2 Department of Dermatology, Imperia Hospital, Imperia, Italy, and 3 Laboratory of Solid Tumors Genetics, Institute for Research on Cancer and Aging of Nice (IRCAN) CNRS UMR 7284/INSERM U1081, Université Côte d’Azur, Nice University Hospital, Nice, France. E-mail: [email protected] # These authors contributed equally to this work. 1 Cellular angiofibroma (CAF) is an uncommon benign mesenchymal tumour that occurs in both sexes, mainly in the genital region. Extragenital CAF is rare, with fewer than 10 cases reported to date (1–3) and, to the best of our knowledge, there has been no report of CAF occurring in the subungual or periungual region. We describe here the first case of CAF of the subungual region of the toe. Im- munohistochemical features and fluorescence in situ hy- bridization (FISH) ruled out more aggressive neoplasms, such as low-grade fibromyxoid sarcoma (LGFMS) and myxoid dermatofibrosarcoma protuberans (DFSP). CASE REPORT A 46-year-old man presented with a 2-year history of onychodys- trophy of the radial aspect of his right big toe. Physical examination revealed a longitudinal area of yellow discoloration extending most of the length of the nail. Head-on view of the nail unit revealed a focal overcurvature of the nail plate and a localized subungual hyperkeratosis, mimicking thickening of the nail plate. However, the distinct honeycomb pattern typical of onychomatricoma was absent. On closer examination, the head of a red nodule was vi- sible with a distal horny cap, which had lifted the nail plate with destruction of the nail plate distally (Fig. 1A). The lesion was tender to pressure. The other nails appeared normal, and palpation revealed no regional lymphadenopathy. Radiography showed a soft-tissue swelling without periostitis or bone erosion. The plaque measured grossly 2 × 1.3 × 1 cm and extended from the matrix to the hyponychium. Removal of the lesion was performed with a longitudinal incision. Histopathologically, the tumour was superficially relatively well-demarcated, with pushing margins separated from the nail epithelium by a thick dermis (Fig. 1B). The deeper borders of the tumour were irregular, with short fascicles infiltrating the sub-nail region. The tumour was composed of bland-looking spindle cells arranged in a vague storiform pattern within a myxoid stroma in- terspersed with wispy collagen bundles (Fig. 1B, C). The abundant vessels were small-to-medium size with thick hyalinized walls (Fig. 1C). There was no cellular atypia and no mitotic figures were found. Numerous mast cells were seen scattered within the myxoid stroma. Nodule of adipose tissue was not observed. Tumour cells displayed strong positivity for CD34, CD10, and focal staining for bcl2 (B-cell lymphoma 2) and p16 (a protein coded by the cyclin- dependent kinase inhibitor 2A gene (CDKN2A), but were negative for nestin, CD99, EMA (epithelial membrane antigen), MUC4 (mucin 4), smooth muscle actin, desmin, oestrogen/progesterone receptors and androgen receptors. Most of the tumour cells were positive for mouse double minute 2 (MDM2) but negative for cyclin dependent kinase 4 (CDK4). FISH analysis ruled out myxoid dermatofibrosarcoma protube- rans (DFSP). Array-comparative genomic hybridization (aCGH) analysis (Fig. 1D) showed only losses of chromosomal segments, notably losses of the long arms of chromosome 13 (including the RB transcriptional corepressor 1 gene, RB1) and chromosome 16. Notably, there was no MDM2 amplification, despite positivity for MDM2 in immunohistochemistry. The overall findings were consistent with a diagnosis of CAF. The tumour was completely excised with free margins. No evi- dence of recurrence with 8 months of follow-up was observed. Accepted Feb 26, 2019; E-published Feb 27, 2019 Fig. 1. (A) Subungual lesion deforming the nail plate of the right big toe. (B) Scanning power (×40) showing a relatively well circumscribed subdermal nodule separated from the nail bed epithelium by a thick nail- bed dermis. The lesion was composed of fascicles of spindled cells embedded in myxoid stroma. (C) Higher magnification (×200) of the prominent vascularization with thick- walled, concentrically, hyalinized vessels. (D) Comparative genomic hybridization on array (aCGH) results: quantitative whole-genome profile showing partial losses of chromosomes 6q, 10p, 13q, 16q and 20p (log ratio –0.50). Black line represents the ratio of intensity of cyanine 5 and cyanine 3, corresponding to the tumour DNA and to the human reference DNA, respectively. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3152 Acta Derm Venereol 2019; 99: 915–916