The Usefulness of Dermoscopy for the Recognition of Malignant Collision Tumors.

BACKGROUND: Preoperative diagnosis of malignant collision tumors (MCT) is extremely difficult. The value of dermoscopy to improve the correct detection of these tumors has not been previously studied. This study aims to evaluate the diagnostic accuracy of MCT with and without dermoscopy and to describe the dermoscopic features of a large series of MCT. METHODS: Dermoscopic images of 161 MCT were evaluated. Clinical and dermoscopic images of histopathologically proven MCT intermingled with other tumors were randomly presented to clinicians with different levels of experience, blinded to the diagnosis and objective of the study. The clinical and dermoscopic diagnostic accuracies were measured separately. RESULTS: A total of 161 histopathologically proven cases of MCT were collected. The most frequent MCT was basal cell carcinoma-seborrheic keratosis collision tumor (CT; 37.9%), followed by basal cell carcinoma-melanocytic nevus CT (19.9%), and melanoma-seborrheic keratosis CT (6.8%). Diagnostic accuracy among experts on dermoscopy was 71.4%. The study included 119 participants. The percentage of correct diagnoses was 8% by naked eye examination and 36.4% by dermoscopy (p < 0.001). The presence of the malignant component in the cases of MCT was not recognizable in 19.1% of cases by naked eye examination and in 11.8% of cases by dermoscopy (p < 0.001). CONCLUSIONS: The diagnosis of MCT can be assisted and clarified by dermoscopy. However, many of these lesions manifest complex morphologies and continue to be challenging, even for experts on dermoscopy. Atypical, uncertain, or non-classifiable lesions still need a complete excision for the final diagnosis.

Dermoscopy of lymphangioma circumscriptum: A morphological study of 45 cases.

BACKGROUND/OBJECTIVES: The dermoscopy of lymphangioma circumscriptum, also known as superficial lymphatic malformation, remains to be clarified. METHODS: Digital dermoscopic images of 45 histopathologically confirmed cases of lymphangioma circumscriptum collected from nine hospitals in Spain, Italy and Turkey were evaluated for the presence of dermoscopic structures and patterns. RESULTS: Our study shows that the most common structure found in lymphangioma circumscriptum was the presence of lacunae (89% of cases). The latter were red or dark-coloured in 18 cases (45%), yellowish or whitish in 14 cases (35%) and multicoloured in eight cases (20%). The second most common dermoscopic structure was the presence of vascular structures, which were found in 82% of cases, followed by white lines (47%), the hypopyon sign or two-tone lacunae (42%) and scales (7%). CONCLUSIONS: Dermoscopy is useful in improving the diagnosis of lymphangioma circumscriptum with characteristic structures and patterns and could assist in elucidating the presence of blood in lymphatic channels.

Dermoscopy of Nodular Hidradenoma, a Great Masquerader: A Morphological Study of 28 Cases.

BACKGROUND: Nodular hidradenoma is an uncommon, benign, adnexal neoplasm of apocrine origin which is a clinical simulator of other tumours. OBJECTIVE: The aim of this study was to evaluate the morphological findings of a large series of nodular hidradenomas under dermoscopic observation. METHODS: Dermoscopic examination of 28 cases of nodular hidradenomas was performed to evaluate specific dermoscopic criteria and patterns. RESULTS: The most frequently occurring dermoscopic features were: (1) in 96.4% of cases, a homogeneous area that covered the lesion partially or totally, the colour of which was pinkish in 46.4% of cases, bluish in 28.6%, red-blue in 14.3%, and brownish in 10.7%; (2) white structures were found in 89.3% of cases; (3) in 82.1% of cases, vascular structures were also observed, especially arborising telangiectasias (39.3%) and polymorphous atypical vessels (28.6%). CONCLUSION: Nodular hidradenomas represent a dermoscopic pitfall, being difficult to differentiate clinically and dermoscopically from basal cell carcinomas and melanomas.

Dermoscopy of Targetoid Hemosiderotic Hemangioma: A Morphological Study of 35 Cases.

BACKGROUND: Targetoid hemosiderotic hemangioma is an uncommon, vascular, benign solitary lesion of lymphatic origin that can be misdiagnosed as other tumors including melanomas. OBJECTIVES: To evaluate the dermoscopic features of a large series of targetoid hemosiderotic hemangiomas. METHODS: Digital dermoscopic images of 35 histopathologically confirmed cases of targetoid hemosiderotic hemangiomas collected from 7 hospitals in Spain and Italy were evaluated for the presence of dermoscopic structures and patterns. RESULTS: The results of our study reveal that the presence of central red and dark lacunae and a peripheral circular reddish-violaceous homogeneous area is the most common dermoscopic pattern in targetoid hemosiderotic hemangioma (71.4%). The targetoid hemosiderotic hemangiomas of our study were correctly diagnosed in 77% of cases. CONCLUSION: Dermoscopy is helpful in improving the diagnosis of targetoid hemosiderotic hemangioma. However, attention must be paid to those cases that dermoscopically may show nontargetoid patterns, which often mimic other lesions, including melanoma.

When basal cell carcinomas became giant: an Italian multicenter study.

BACKGROUND: Giant basal cell carcinoma (GBCC) is a basal cell carcinoma (BCC) enlarged in a diameter more than 5 cm. Since GBCCs are a highly infrequent entity and the occurrence rate is approximately 0.5-1% out of all BCC types, only anecdotal cases are reported, and causes and characteristics inducing development of this tumor are not defined. OBJECTIVES: Evaluate causative factors and clinico-histological characteristics of GBCCs. METHODS: The study is a 6-month, hospital-based case series study performed in 12 Italian dermatologic centers. RESULTS: A total of 59 cases and 458 control BCCs were collected. No significant differences existed between the two groups if we take into account social or cultural factors. The average duration of GBCCs is considerably longer than controls. GBCCs are located on unexposed areas while BCCs are on areas not usually covered by clothes. Superficial histological subtype was more frequent in the BCCs group, while infiltrative in GBCCs. GBCCs showed significantly higher local invasiveness, and greater metastatic capacity. More than half of GBCCs had been previously treated with one or more treatments. CONCLUSIONS: Patients with GBCCs appear to belong to two categories: (i) those who present with GBCC due to delay in accessing medical attention, and (ii) those who have BCCs previously treated with inappropriate strategies. Only very few cases can be carried out with intrinsic biological features of tumor aggressiveness. Social and cultural conditions do not appear to be involved in the development of GBCCS. These observations may help clinicians in selecting correct therapeutic strategies in the treatment of BCCs, which give rise to GBCC.

Dermoscopic evaluation of nodular melanoma.

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.