SUBMITTED 14 MAR 23 1 REVISION REQ. 13 APR 23; REVISION RECD. 18 APR 23 2 ACCEPTED 3 MAR 23 3 ONLINE-FIRST: MAY 2023 4 DOI: https://doi.org/10.18295/squmj.5.2023.034 5 6 Erythematous Plaque in the Left Axillary Region 7 A diagnostic challenge where dermoscopy can help 8 Maria D. Pegalajar-García,1 Jose Mellado,2 *Ricardo Ruiz-Villaverde,1 9 Francisco J. Navarro-Triviño1 10 11 1Dermatology Department, Hospital Universitario San Cecilio, Granada, Spain; 12 2Pathological Anatomy, Analizalab-HLA Inmaculada, Granada. Spain. 13 *Corresponding Author’s e-mail: ismenios@hotmail.com 14 15 A 70-year-old male patient was attended in our outpatient dermatological clinic for a 16 plaque on left axillae of unknown time of evolution. Physical examination revealed an 17 erythematous plaque with no desquamative component (Fig. 1A). Dermoscopy showed 18 thick reticular white lines, white clods, and structureless areas (Fig. 1B), dotted and linear 19 vessels, and a sessile projection in the lower part of the plaque. Histological examination 20 using a 4 mm punch biopsy revealed a hyperkeratotic epidermis without dyskeratosis, with 21 intraepidermal infiltration of dysplastic cells distributed singly and in clusters (Fig.1C). 22 Immunohistochemistry staining of this tumoral component was positive for GCDFP-15, 23 mammaglobin and CK7, and negative for HMB45 and S-100 protein, which was 24 consistent with the diagnosis of extramammary Paget's disease (EMPD). Complementary 25 examinations (body-TC, a complete blood test with hemogram, liver and renal function, 26 ions, protein S100b and PSA; colonoscopy and mammary ecography) ruled out the 27 presence of concomitant tumour. The lesion was completely removed through wide local 28 excision and primary closure, with no local recurrence or distant metastasis during the 29 following 12-months. He is currently under long-term follow-up with periodic revisions 30 every 6 months. 31 32 Comment 33 EMPD is an infrequent cutaneous adenocarcinoma with unknown incidence, which 34 predominantly affects postmenopausal Caucasian women and Asian men aged between 60 35 and 80 years old. It is usually presented as a slow-growing rounded or oval erythematous 36 plaque, asymptomatic or pruritic, located in genital, perianal or, less frequently, axillary 37 regions.1 Dermoscopy is a non-invasive technique which raises suspicion of EMPD. 38 Pigmented, whitish and reddish structures represent the main groupof dermoscopy 39 patterns. Glomerular and dotted vessels are the most common vascular patterns. Lava lake 40 structures (BAW) and cloud-like structureless areas (WAW) were described by 41 Payapvipapong et al.4 None of the patients had axillary lesions, practically all of them 42 were located in the ano-genital region. This could explain the fact that we have not 43 observed BAW and WAW in our patient. Histology allows to distinguish between EMPD 44 and other diagnoses such as Langerhans cell histiocytosis, Bowen’s disease, amelanotic 45 melanoma and mycosis fungoides (Table 1).1 46 The most relevant prognostic factor is the presence of underlying malignancy, either a 47 contiguous tumour (23% of cases) or a distant one (8%-46% of cases). Underlying cancer 48 screening might include a complete physical examination with lymph node and breast 49 examination. Complementary tests may include urine cytology and colonoscopy for both 50 genders, PSA blood test and digital rectal examination in male patients, and Papanicolaou 51 test and mammography in female patients.2 52 Primary cases, as the one we present, are usually indolent, with good survival rates. Wide 53 local excision is the gold standard treatment, although imiquimod, photodynamic therapy 54 or radiotherapy could be considered in non-surgical cases.1,3 Recurrence rates are 55 considerably elevated regardless of the treatment, so a long-term follow-up based on a 56 careful physical examination is highly recommended.1 57 The authors have obtained patient consent for publication purposes. 58 59 Authors’ Contribution 60 All authors contributed equally in the conceptualization, design, data acquisition, analysis 61 and write up of the manuscript. 62 63 References 64 1.Simonds RM, Segal RJ, Sharma A. Extramammary Paget's disease: a review of the 65 literature. Int J Dermatol. 2019;58:871-879. doi: 10.1111/ijd.14328 66 2. Schmitt AR, Long BJ, Weaver AL, McGree ME, Bakkum-Gamez JN, Brewer JD et al. 67 Evidence-Based Screening Recommendations for Occult Cancers in the Setting of Newly 68 Diagnosed Extramammary Paget Disease. Mayo Clin Proc. 2018;93:877-883. 69 10.1016/j.mayocp.2018.02.024 70 3. Liao X, Liu X, Fan X, Lai J, Zhang D. Perianal Paget's disease: a clinicopathological 71 and immunohistochemical study of 13 cases. Diagn Pathol. 2020;15:29. 10.1186/s13000-72 020-00952-w 73 4. Payapvipapong K, Nakakes A, Tanaka M. Lava lake structure and cloud-like 74 structureless area: new clues for diagnosing extramammary Paget disease. J Eur Acad 75 Dermatol Venereol. 2017;31(10):e459-e461. doi: 10.1111/jdv.14279. 76 77 78 Figure 1: (A) Round erythematous plaque with slightly raised edges without scaling or 79 ulceration, located on the left axilla (black arrow: biopsy area); (B) Dermoscopy showed 80 milky red structureless areas, reticular white lines (red arrow) and white clods (black 81 arrow). Dotted and linear vessels (asterisk) werethe vascular pattern identified; (C) 82 Epidermis with hyperkeratosis without dyskeratosis, with a component of dysplastic cells 83 distributed singly and in clustered, with the following features (black arrow): large cells 84 with pale cytoplasm and irregular nuclei with visible nucleoli, most of them just above the 85 epidermal basal layer, with others ascending to intermediate epidermal strata (H&E 4x). 86