DERMOSCOPY Melanomas That Failed Dermoscopic Detection: A Combined Clinicodermoscopic Approach for Not Missing Melanoma SUSANA PUIG, MD, Ã GIUSEPPE ARGENZIANO, MD, y IRIS ZALAUDEK, MD, yz GERARDO FERRARA, MD, y JOSE PALOU, MD, y DANIELA MASSI, MD, J RAINER HOFMANN-WELLENHOF , MD, z H. PETER SOYER, MD, z AND JOSEP MALVEHY , MD Ã OBJECTIVE The objective was to describe the clinical and dermoscopic characteristics of difficult-to- diagnose melanomas (DDM). DESIGN This study was a retrospective analysis of clinical data and dermoscopic images in a series of excised melanomas. SETTING Cases were obtained from the database registers of three public hospitals in Barcelona (Spain), Naples (Italy), and Graz (Austria). PATIENTS A total of 97 tumors with a main preoperative diagnosis different from melanoma and with- out sufficient criteria to be diagnosed clinically and dermoscopically as melanoma were studied. We studied clinical data from the patients and lesions, mean reason for excision, and consensus dermoscopic description of the lesions according to pattern analysis performed by a panel of four dermoscopists to obtain clues that allow these melanomas to be recognized. RESULTS Ninety-three DDMs were evaluated. Three main dermoscopic categories of DDM have been identified: (1) DDMs lacking specific features (16/97), (2) DDMs simulating nonmelanocytic lesions (14/ 93), and (3) DDMs simulating benign melanocytic proliferations (67/93). The reasons for excision were (1) the subjective history of change referred by the patient (38% of cases), (2) the presence of clinical and/or dermoscopic ‘‘hints’’ for biopsy (33% of cases), and (3) the objective evidence of changes detected by digital dermoscopic follow-up (29% of cases). CONCLUSIONS A diagnostic algorithm is proposed not to miss melanoma. The authors have indicated no significant interest with commercial supporters. E arly diagnosis and prompt surgical excision are the main goals in the secondary prevention of cutaneous melanoma (CM). 1 The current practice in the diagnosis of CM is based on the ABCD rule, 2 which considers four clinical features commonly seen in this tumor (asymmetry, border irregularity, color variegation, and diameter more than 5 mm). Although most CM will be correctly diagnosed using this rule, a variable proportion of CM lacks these criteria. Moreover, the clinical unassisted diagnosis of CM can be unsatisfactory especially in the case of patients with multiple nevi. Very early CM and nodular CM can sometimes be symmetric, well- demarcated, homogeneously pigmented, and smaller than 5 mm in size. Further diagnostic difficulties may occur when CM mimics other pigmented skin lesions (PSLs) or lacks pigmentation, as is the case of amelanotic melanoma. In an effort to improve the & 2007 by the American Society for Dermatologic Surgery, Inc.  Published by Blackwell Publishing  ISSN: 1076-0512  Dermatol Surg 2007;33:1262–1273  DOI: 10.1111/j.1524-4725.2007.33264.x 1262 Ã Melanoma Unit, Dermatology Department, Hospital Clı´nic i Provincial de Barcelona, IDIBAPS, Barcelona, Spain; y Department of Dermatology, Second University of Naples, Naples, Italy; z Department of Dermatology, Medical University of Graz, Graz, Austria; y Pathologic Anatomy Service, Gaetano Rummo General Hospital, Benevento, Italy; J Department of Human Pathology and Oncology, University of Florence, Florence, Italy