Clinicopathological, dermoscopic features and circumstances of diagnosis of amelanotic or hypomelanotic melanoma: A prospective multicentric study in the French private medical sector.

BACKGROUND: Amelanotic or hypomelanotic melanomas (AHM) are difficult to diagnose, and are often diagnosed late, with a high Breslow index and a poor prognosis. PATIENTS AND METHODS: A total of 226 volunteer dermatologists consulting in private practice in France completed an online form for each new histologically proven case of melanoma diagnosed at their clinic in 2020. This anonymised survey collected data on the clinical, dermoscopic, and histological features of melanoma, as well as the circumstances of diagnosis and initial management. A group of 145 AHM was single out and compared to the 1503 pigmented melanomas (PM) from the same cohort. RESULTS: 1503 pigmented melanomas (PM) and 145 AHM (8.8% of these melanomas) were identified and included. In the AHM group, the mean age at diagnosis was 65 ±â€¯16 years, with no significant difference from the PM control group. AHM were not predominantly on the face and neck area, and there were no differences based on gender. Warning signs (local progression and bleeding) were significantly more frequent in the AHM group than in the PM group. AHM were more frequently ulcerated and nodular, with a higher median Breslow thickness than in the PM group (1.56 vs. 0.5 mm), and mitoses were more frequent. Dermoscopy was widely used and proved useful for distinguishing benign lesions, and for highlighting the vascular polymorphous pattern of malignant lesions. Patients noticed the suspicious lesion themselves in most cases of AHM (73.2%), as opposed to their general practitioner (17.2%) or entourage (9.5%). A total body skin examination enabled detection of 19.3% of AHM and 21.3% of PM where the patient consulted for another lesion, or for an unrelated reason. CONCLUSION: AHM are difficult to diagnose for the clinician because of the paucity or absence of pigmentary criteria. Knowledge of dermoscopic vascular patterns is critical and could help reduce the median Breslow index of AHM at the time of detection. Self-examination of the skin should be encouraged, and simple algorithms for earlier detection of skin cancers should be promoted among health professionals and the general population.

Sclerodermiform basal cell carcinomas vs. other histotypes: analysis of specific demographic, clinical and dermatoscopic features.

BACKGROUND: Among the various types of basal cell carcinoma, the sclerodermiform variant has a high risk of recurrence and local invasiveness. A systematic description of the dermatoscopic features associated with specific body localization is lacking. OBJECTIVES: To describe the clinical and dermoscopic features of sclerodermiform basal cell carcinoma (BCC) according to localization in the body confronting with superficial and nodular types. METHODS: Clinical and dermoscopic images of sclerodermiform, nodular and superficial BCCs were retrospectively evaluated to study the location in the various body districts, maximum diameter, clinical appearance of the lesion, features of edges and presence or absence of specific dermatoscopic criteria of BCCs. RESULTS: We examined 291 histopathologically proven BCCs showing that in nodular BCCs, classical arborizing vessels were more frequently found in the body macro-area (trunk and limbs; n = 46, 97.9%) than in the head/neck area (n = 43, 82.7%); within sclerodermiform BCCs, short arborizing vessels were found more frequently in the head/neck district (n = 35, 49.3%) than in the body (n = 6, 23.1%; P-value 0.02); within nodular BCCs, multiple blue-grey dots and globules were more frequently found on the trunk (n = 23, 48.9%) than in the head/neck district (n = 12, 23.1%; P-value 0.01). In sclerodermiform BCCs, ulceration was found more frequently in the head/neck district (n = 38, 53.5%) than in the body (n = 4, 15.4%; P-value > 0.01), and in superficial BCCs, ulceration was found more frequently in the head/neck district (n = 5, 38.5%) than in the body (n = 8, 9.8%; P-value 0.02). CONCLUSION: Our study shows that superficial BCC are found frequently in the head/neck district dermoscopically characterized by ulceration and arborizing vessels; nodular BCCs are more frequently found in the body than in the head/neck district, and the dermoscopic pattern is characterized by the combination of three features: (i) classical arborizing vessels, (ii) multiple blue-grey dots and (iii) globules. Instead, sclerodermiform BCC is preferentially located in areas at high-moderate risk of recurrence; if pink-white areas and/or fine arborizing vessels are seen, clinicians should consider this diagnosis. Furthermore, location-specific dermatoscopic criteria have been described.

Dermoscopic clues to differentiate facial lentigo maligna from pigmented actinic keratosis.

BACKGROUND: Dermoscopy is limited in differentiating accurately between pigmented lentigo maligna (LM) and pigmented actinic keratosis (PAK). This might be related to the fact that most studies have focused on pigmented criteria only, without considering additional recognizable features. OBJECTIVES: To investigate the diagnostic accuracy of established dermoscopic criteria for pigmented LM and PAK, but including in the evaluation features previously associated with nonpigmented facial actinic keratosis. METHODS: Retrospectively enrolled cases of histopathologically diagnosed LM, PAK and solar lentigo/early seborrhoeic keratosis (SL/SK) were dermoscopically evaluated for the presence of predefined criteria. Univariate and multivariate regression analyses were performed and receiver operating characteristic curves were used. RESULTS: The study sample consisted of 70 LMs, 56 PAKs and 18 SL/SKs. In a multivariate analysis, the most potent predictors of LM were grey rhomboids (sixfold increased probability of LM), nonevident follicles (fourfold) and intense pigmentation (twofold). In contrast, white circles, scales and red colour were significantly correlated with PAK, posing a 14-fold, eightfold and fourfold probability for PAK, respectively. The absence of evident follicles also represented a frequent LM criterion, characterizing 71% of LMs. CONCLUSIONS: White and evident follicles, scales and red colour represent significant diagnostic clues for PAK. Conversely, intense pigmentation and grey rhomboidal lines appear highly suggestive of LM.

Dermoscopic patterns of common facial inflammatory skin diseases.

BACKGROUND: Several common inflammatory dermatoses, such as rosacea, seborrheic dermatitis (SD), discoid lupus erythematosus (DLE) and granulomatous skin diseases manifest as erythematous macules or plaques on the facial skin. Although clinical examination represents the cornerstone of diagnosis, the broad variety of clinical features and uncommon presentations of these diseases may cause at times diagnostic and therapeutic uncertainty. Dermoscopy, in addition to its well-documented value in evaluation of skin tumours, is continuously gaining appreciation also in the field of general dermatology. OBJECTIVE: To describe and compare the dermoscopic patterns of common facial inflammatory skin diseases including SD, erythematotelangiectatic rosacea (ER), sarcoidosis, lupus vulgaris (LV), DLE and granuloma faciale (GF). METHODS: Dermoscopic images of lesions from patients with histopathologically confirmed diagnosis of SD, ER, sarcoidosis, LV, DLE or GF were retrospectively evaluated for the presence of several criteria. Selection of the dermoscopic variables included in the evaluation process was based on the data available in the literature and on our preliminary observations. RESULTS: One hundred and fifteen dermoscopic images were included in the study. SD was dermoscopically characterized by dotted vessels and yellow scales, whereas ER was typified by a characteristic pattern of vascular polygons. Sarcoidosis and LV very commonly exhibited orange-yellowish areas and linear branching vessels. Features related to follicle abnormalities and linear branching vessels were the most common dermoscopic criteria of DLE and GF. CONCLUSIONS: This study provides new insights into the dermoscopic variability in common facial inflammatory dermatoses.

Dermoscopy of scalp tumours: a multi-centre study conducted by the international dermoscopy society.

BACKGROUND: Little is known about the dermoscopic features of scalp tumours. Objective To determine the dermoscopic features of scalp tumours. METHODS: Retrospective analysis of dermoscopic images of histopathologically diagnosed scalp tumours from International Dermoscopy Society members. RESULTS: A total of 323 tumours of the scalp from 315 patients (mean age: 52 years; range 3-88 years) were analysed. Scalp nevi were significantly associated with young age (<30 years) and exhibited a globular or network pattern with central or perifollicular hypopigmentation. Melanoma and non-melanoma skin cancer were associated with male gender, androgenetic alopecia, age >65 years and sun damage. Atypical network and regression were predictive for thin (≤1 mm) melanomas, whereas advanced melanomas (tumour thickness > 1 mm) revealed blue white veil, unspecific patterns and irregular black blotches or dots. CONCLUSIONS: The data collected provide a new knowledge regarding the clinical and dermoscopy features of pigmented scalp tumours.

Blue-black rule: a simple dermoscopic clue to recognize pigmented nodular melanoma.

BACKGROUND: Dermoscopy improves melanoma recognition, but most criteria were described in the context of superficial spreading melanoma. OBJECTIVES: To test whether pigmented nodular melanoma could be recognized dermoscopically by the presence of a combination of blue and black colour within the lesion. METHODS: Dermoscopic images of histopathologically diagnosed pigmented nodular tumours with no (or only minimal) flat component were evaluated for the presence of standard melanoma criteria and for the presence of a new feature named blue-black (BB) colour. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for standard criteria and BB feature in relation to the diagnosis of melanoma and to diagnosis of malignancy. RESULTS: Of 283 lesions, 160 were malignant, including 78 (27·6%) melanomas, and 123 were benign. The BB feature and the standard criteria had 78·2% and 43·6% sensitivity for melanoma, respectively, whereas a combined method based on the presence of either the BB feature or one (or more) of the standard criteria reached 84·6% sensitivity, with 80·5% specificity and 93·2% negative predictive value. Sensitivity values for malignant lesions were only 24·4%, 56·9% and 60% for standard criteria, BB feature and the combined method, respectively. However, the combined method gave 91·9% specificity and 90·6% positive predictive value for malignancy. CONCLUSIONS: Using a method based on the BB feature or one of the standard melanoma criteria, only 9·4% of positive pigmented nodular lesions were found to be benign and only 6·8% of negative lesions were found to be melanoma histopathologically.