ABSTRACT
BACKGROUND: Eccrine poroma is a benign neoplasm that can mimick a malignant neoplasm dermoscopically. The characteristic vascular pattern of this tumor has not been established. OBJECTIVE: To evaluate dermoscopic features of non-pigmented eccrine poroma in Mexican patients. METHOD: We retrospectively studied histologically proven cases of eccrine poroma from three Mexican hospitals analyzed by four dermoscopists. RESULTS: Thirteen cases were studied. A polymorphous vascular pattern was found in most cases. Four presented with irregular linear and branched vessels with semi-elliptical, or semicircular endings ("chalice-form" and "cherry-blossoms" vessels). Structureless pink-white areas were the most common other dermoscopic finding. CONCLUSIONS: "Chalice-form" and "cherry-blossom" vessels have not been reported in other benign or malignant neoplasms and can be a useful clue to the diagnosis of non-pigmented eccrine poroma. Due to the variability of dermoscopic patterns of eccrine poroma further studies are required to establish the specificity of our findings.
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, blue-white veil, homogeneous blue pigmentation, 5 to 6 colors, and black color. A model to classify a lesion as melanocytic gave a high sensitivity (>98.0%) 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.
