Dermoscopy of haemosiderotic/aneurysmal dermatofibroma: A morphological study of 110 cases.

BACKGROUND: Haemosiderotic and aneurysmal dermatofibromas are uncommon and frequently misdiagnosed lesions, which can be considered as different histopathological stages of the same tumour. A dermoscopic diagnosis testing accuracy has not been performed for these tumours to date. OBJECTIVES: To determine the diagnostic significance of dermoscopic structures and patterns associated with haemosiderotic/ aneurysmal dermatofibromas in a large series. METHODS: Dermoscopic images of histopathologically proven cases of 110 haemosiderotic/ aneurysmal dermatofibromas and 501 other tumours were collected. The frequency, sensitivity, specificity, positive predictive value and negative predictive value of the dermoscopic structures and patterns associated with these lesions were calculated. RESULTS: Haemosiderotic/ aneurysmal dermatofibromas are mostly symmetric lesions (86.5%), and a prominent homogeneous area was present in 100% of them. The presence of vascular structures was very common (86.4%), and dotted vessels were predominant (58.2%). Shiny white structures were seen in 85.5% of lesions, while a peripheral delicate pigment network was present in 69.1%. The most significant pattern was the one composed of a prominent homogeneous area and peripheral delicate pigment network, which showed a specificity of 100% with a relatively good sensitivity (69.1%). All the patterns containing a peripheral delicate pigment network showed very good specificities, positive predictive values and negative predictive values. Those patterns without a peripheral delicate pigment network showed the highest sensitivities, but they showed a significant overlap with other tumours, mainly with melanoma. CONCLUSIONS: Dermoscopy is helpful in improving the diagnostic accuracy of haemosiderotic/ aneurysmal dermatofibromas. However, there is a considerable dermoscopic overlap between these tumours and melanoma, specifically when the peripheral delicate pigment network is absent.

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.

Intralesional photodynamic therapy in hidradenitis suppurativa: Getting closer to the target.

BACKGROUND: The successful treatment of hidradenitis suppurativa (HS) with intralesional photodynamic therapy (IL-PDT) has been previously reported in some case series published a few years ago. We present additional data and patient outcome for this form of PDT. METHODS: This is an observational retrospective study including all patients diagnosed with HS and treated with IL-PDT in the Hospital Universitari Son Espases from February 2019 to February 2020. Under local or general anesthesia, 5-aminolevulinic acid (5ALA) in gel 2 % or solution 1 % was introduced in the lesion. After two hours, the lesion was intralesionally irradiated (1.4 W, fluence 168 J/cm2) with the tip of a 0.4-mm thick optical fiber connected to a continuous 630-nm diode laser. The main outcome variable was the result (remission, improvement or no change) for each lesion 3 months after the therapy. The result at 6 months and the side effects were secondary outcomes. A multivariate analysis was carried out in order to obtain adjusted odds ratios for no change vs improvement or remission at 3 months for significant variables. RESULTS: A total of 117 lesions (28 nodules and 89 fistulae) were treated in 42 patients. At 3 months, 26 lesions (22.2 %) had resolved, 73 (62.4 %) had improved in size or symptoms, and 18 (15.4 %) experienced no change. The most frequent side effects were skin burns (53 lesions, 45.3 %), and abscess formation (8 lesions, 6.8 %). In the multivariate analysis, significant variables for no benefit were: a higher International Hidradenitis Suppurativa (IHS4) score, active smoking and gluteal and inguinal location. CONCLUSIONS: Although our results did not present the level of remission of the previous studies, IL-PDT was useful in most of our patients. Early interventions in patients with lower inflammatory burden were the most valuable.

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.

Dermoscopic Visualization of Vellus Hair Involvement in Tinea Corporis: A Criterion for Systemic Antifungal Therapy?

Dermoscopy has been shown to be a valuable tool in the diagnosis and monitoring of several infectious diseases. We report a case of tinea corporis in an infant in whom dermoscopy helped us to determine vellus hair involvement, causing treatment to be switched from topical to systemic antifungal therapy.