Acta Dermato-Venereologica 99-1CompleteContent | Page 13

33 CLINICAL REPORT Diagnostic Accuracy of Non-melanocytic Pink Flat Skin Lesions on the Legs: Dermoscopic and Reflectance Confocal Microscopy Evaluation Ignacio GÓMEZ-MARTÍN 1 , Sara MORENO 1 , Xavier DURAN 2 , Ramon M. PUJOL 1 and Sonia SEGURA 1 Department of Dermatology, Hospital del Mar-Parc de Salut Mar, Universitat Autònoma de Barcelona, 2 Department of Statistics, Institut Hospital del Mar d’Investigacions Mèdiques (IMIM), Barcelona, Spain 1 Pink flat skin lesions on the legs in elderly people re- present a diagnostic challenge due to the paucity of clinical and dermoscopic evidence. A prospective stu- dy of 114 pink flat lesions on the legs of 85 elderly patients was performed to describe the utility of re- flectance confocal microscopy in this clinical context. Evaluation of clinical, dermoscopic and confocal para- meters and calculation of diagnostic accuracy/sensi- tivity/specificity for non-melanoma skin cancer diag- nosis of each technique were carried out. Thirty-four benign and 80 malignant neoplasms were analysed. A correct clinical diagnosis was establish­ed in 49.1% of cases (sensitivity 68.7%, specificity 73.5%). Der- moscopy achieved 59.6% correct diagnosis (sensiti- vity 85%, specificity 67.6%) and confocal microscopy evaluation after clinical and dermoscopic evaluation rendered a correct diagnosis in 85.1% of cases (sensi- tivity 97.5%, specificity 88.2%). Confocal microscopy may improve diagnostic accuracy, sensitivity and spe- cificity as a secondary evaluation after dermoscopy. A diagnostic confocal algorithm for pink flat lesions on the legs is proposed. Key words: dermoscopy; reflectance confocal microscopy; his- topathology; basal cell carcinoma; Bowen’s disease; venous stasis dermatitis. Accepted Aug 31, 2018; Epub ahead of print Sep 3, 2018 Acta Derm Venereol 2019; 99: 33–40. Corr: Ignacio Gómez-Martín, Department of Dermatology, Hospital del Mar-Parc de Salut Mar. Universitat Autònoma de Barcelona, Passeig Ma- rítim 25–29, ES-08003, Barcelona, Spain. E-mail: [email protected] P ink flat skin lesions on the legs of elderly people exhibit a broad differential diagnosis (1, 2). They represent a diagnostic challenge due to the paucity of clinical and dermoscopic morphological clues, and the existence of varying degrees of associated xerosis, sun damage and venous stasis dermatitis. Pink flat skin le- sions often present with non-specific overlapping clinical and dermoscopic features (3–11). Furthermore, on dermoscopy, pink lesions on the lo- wer limbs usually exhibit prominent, but non-specific, vasculature due to orthostatic blood pressure. Differential diagnosis includes tumoural lesions (Bowen’s disease (BD), actinic keratosis (AK), invasive squamous cell carcinoma (SCC), basal cell carcinoma (BCC), amelanotic/hypomelanotic melanoma, seborr- SIGNIFICANCE Pink flat skin lesions on the legs represent a diagnostic challenge due to the paucity of specific clinical and dermo­ scopic features. A prospective study of a series of 114 pink flat skin lesions on the legs in elderly people was perfor- med  to describe the utility of reflectance confocal micro­ scopy (RCM) in this clinical context. RCM resulted in 85.1% diagnostic accuracy, 97.5% sensitivity and 88.2% specifi- city for non-melanoma skin cancer diagnosis. A diagnostic RCM algorithm for pink flat lesions on the legs is proposed. RCM, as a secondary evaluation after dermoscopy, may im- prove diagnostic accuracy, sensitivity and specificity and may avoid the need for invasive biopsies. hoeic keratosis (SK), clear cell acanthoma, melanocytic naevus, angiomas, dermatofibroma, neurofibroma), inflammatory lesions (venous stasis dermatitis (VSD), lichen planus (LP), lichen planus-like keratosis (LPLK), porokeratosis, psoriasis, lichen aureus, lichen simplex chronicus) or infectious diseases (flat wart). Dermoscopic algorithms used routinely for pigmented lesions are often not very helpful in the diagnosis of pink lesions. Several years ago, Giacomel & Zalaudek (12) suggested an algorithm for hypopigmented lesions based on vessel morphology, vascular architectural ar- rangement and additional criteria, and soon afterwards Zalaudek et al. (13) proposed including an initial clinical assessment and search for specific patterns. Rosendahl et al. (14) also described an algorithm for non-pigmented skin malignancies based on pattern analysis: first, looking for ulceration; secondly, for white clues; and thirdly, ves- sel analysis. However, these algorithms have not been tested in prospective studies for sensitivity, specificity or diagnostic accuracy. In this particular clinical context, in which only scarce dermoscopic criteria are specific, reflectance confocal microscopy (RCM) may offer specific diagnostic criteria. RCM might achieve a confidence close to histopathology (gold standard) and may permit a decrease in the number of required biopsies, reducing costs and potential com- plications (pain, cellulitis and chronic ulcers). The aim of the current study was to describe the utility of RCM in pink flat skin lesions on the legs in photoda- maged skin, to characterize the dermoscopic and RCM criteria of the different skin conditions that present as This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3029 Acta Derm Venereol 2019; 99: 33–40