Monitoring patients at extreme risk with TBP and SDDI assisted with early diagnosis of primary melanoma. Hypervigilance for difficult-to-detect thick melanoma subtypes is crucial.

Importance: Nodular melanoma (NM) is a rapidly progressing potentially lethal skin tumor for which early diagnosis is critical.Objective: To determine the dermoscopy features of NM.Design: Eighty-three cases of NM, 134 of invasive non-NM, 115 of nodular benign melanocytic tumors, and 135 of nodular nonmelanocytic tumors were scored for dermoscopy features using modified and previously described methods. Lesions were separated into amelanotic/ hypomelanotic or pigmented to assess outcomes.Setting: Predominantly hospital-based clinics from 5 continents.Main Outcome Measures: Sensitivity, specificity, and odds ratios for features/models for the diagnosis of melanoma.Results: Nodular melanoma occurred more frequently as amelanotic/hypomelanotic (37.3%) than did invasive non-NM (7.5%). Pigmented NM had a more frequent (compared with invasive non-NM; in descending order of odds ratio) symmetrical pigmentation pattern (5.8% vs 0.8%), large-diameter vessels, areas of homogeneous blue pigmentation, symmetrical shape, predominant peripheral vessels, blue-white veil, pink color, black color, and milky red/pink areas. Pigmented NM less frequently displayed an atypical broadened network, pigment network or pseudonetwork, multiple blue-gray dots, scarlike depigmentation, irregularly distributed and sized brown dots and globules, tan color, irregularly shaped depigmentation, and irregularly distributed and sized dots and globules of any color. The most important positive correlating features of pigmented NM vs nodular nonmelanoma were peripheral black dots/globules, multiple brown dots, irregular black dots/globules, bluewhite veil, homogeneous blue pigmentation, 5 to 6 colors, and black color. A model to classify a lesion as melanocytic gave a high sensitivity (Ͼ98.0%) for both nodular pigmented and nonnodular pigmented melanoma but a lower sensitivity for amelanotic/hypomelanotic NM (84%). A method for diagnosing amelanotic/hypomelanotic malignant lesions (including basal cell carcinoma) gave a 93% sensitivity and 70% specificity for NM.Conclusions and Relevance: When a progressively growing, symmetrically patterned melanocytic nodule is identified, NM needs to be excluded.

IMPORTANCEA previous single-center study observed fewer excisions, lower health care costs, thinner melanomas, and better quality of life when surveillance of high-risk patients was conducted in a melanoma dermatology clinic with a structured surveillance protocol involving full-body examinations every 6 months aided by total-body photography (TBP) and sequential digital dermoscopy imaging (SDDI).OBJECTIVE To examine longer-term sustainability and expansion of the surveillance program to numerous practices, including a primary care skin cancer clinic setting. DESIGN, SETTING, AND PARTICIPANTSThis prospective cohort study recruited 593 participants assessed from 2012 to 2018 as having very high risk of melanoma, with a median of 2.9 years of follow-up (interquartile range, 1.9-3.3 years), from 4 melanoma high-risk clinics (3 dermatology clinics and 1 primary care skin cancer clinic) in New South Wales, Australia. Data analyses were conducted from February to September 2020.EXPOSURES Six-month full-body examination with the aid of TBP and SDDI. For equivocal lesions, the clinician performed SDDI at 3 or 6 months. MAIN OUTCOMES AND MEASURESAll suspect monitored or excised lesions were recorded, and pathology reports obtained. Outcomes included the incidence and characteristics of new lesions and the association of diagnostic aids with rates of new melanoma detection. RESULTS Among 593 participants, 340 (57.3%) were men, and the median age at baseline was 58 years (interquartile range, 47-66 years). There were 1513 lesions excised during follow-up, including 171 primary melanomas. The overall benign to malignant excision ratio, including keratinocyte carcinomas, was 0.8:1.0; the benign melanocytic to melanoma excision ratio was 2.4:1.0; and the melanoma in situ to invasive melanoma ratio was 2.2:1.0. The excision ratios were similar across the 4 centers. The risk of developing a new melanoma was 9.0% annually in the first 2 years and increased with time, particularly for those with multiple primary melanomas. The thicker melanomas (>1-mm Breslow thickness; 7 of 171 melanomas [4.1%]) were mostly desmoplastic or nodular (4 of 7), self-detected (2 of 7), or clinician detected without the aid of TBP (3 of 7). Overall, new melanomas were most likely to be detected by a clinician with the aid of TBP (54 of 171 [31.6%]) followed by digital dermoscopy monitoring (50 of 171 [29.2%]). CONCLUSIONS AND RELEVANCEThe structured surveillance program for high-risk patients may be implemented at a larger scale given the present cohort study findings suggesting the sustainability and replication of results in numerous settings, including a primary care skin cancer clinic.