Dermoscopic Evaluation of Nodular Melanoma

Abstract

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.

Diagnostic spectrum of nodular melanoma

“…Nodular melanoma is defined as an invasive melanoma lacking a significant component of epidermal tumor cells beyond the dermal invasive component (1). It represents 10 to 30% of all melanomas (second for frequency after superficial spreading melanoma SSM) and about 50% of melanomas with a depth greater than 2 mm (2).…”

Modern non-invasive diagnostic techniques in the detection of early cutaneous melanoma

“…Remnants of pigmemtation in conjunction with listed above vessel types and their distribution are the key to diagnosis of amelanotic and hypomelanotic melanoma. 21 The so-called "desmoplastic melanoma" is devoid of the characteristic dermoscopic features. The unusual clinical and dermoscopic features often lead to a delay in diagnosis.…”

“…Ulceration is present in half the cases of nodular melanoma. 17,21 Acral melanomas are located on palms, soles, fingers, toes and in the nail unit. The dermoscopic features of melanomas located on the palms and soles were described Saida et al 22 The two most prevalent features were irregular diffuse pigmentation and the parallel-ridge pattern with a sweat glands infiltration.…”

Fuzzy Color Clustering for Melanoma Diagnosis in Dermoscopy Images

“…Diagnosis of early-stage melanomas is challenging, especially for melanomas which have an atypical presentation [1][2][3][4]. Dermoscopy is an imaging modality that uses a simple hand-held device that eliminates surface glare and magnifies structures invisible to the naked eye.…”

“…The remaining sections of the paper include: (1) an overview of dermoscopy image acquisition; (2) the fuzzy logic technique for color histogram analysis and color feature determination; (3) an overview of the lesion region analysis; (4) the automated approach for melanoma detection; (5) experiments performed; (6) results and discussion and (7) conclusions.…”