Typical and atypical dermoscopic presentations of dermatofibroma

Dermoscopy of Basal Cell Carcinoma Part 3: Differential Diagnosis, Treatment Monitoring and Novel Technologies

Introduction: Basal cell carcinoma (BCC) is the most frequently diagnosed skin cancer globally. Despite the well-established dermoscopic features of BCC, overlapping characteristics with other benign and malignant skin conditions cause challenges in differential diagnosis. Part III of this review highlights the role of dermoscopy in differential diagnosis, treatment planning, therapy monitoring and the integration of novel technologies including ultraviolet-induced fluorescence dermoscopy (UVFD) and optical super-high magnification dermoscopy (OSHMD). Methods: A search of the PubMed database was conducted for studies reporting on advances in the dermoscopic assessment of BCC, including differential diagnosis, treatment, monitoring and novel diagnostic technologies. Results: Even entities with well-defined dermoscopic features distinguishing them from BCC can sometimes mimic BCC. Additionally, rare lesions such as neurothekeoma, reticulohistiocytoma, solitary circumscribed neuroma, dermal leiomyosarcoma and various adnexal tumors often remain dermoscopically indistinguishable from BCC, which underscores the importance of histopathology as the diagnostic gold standard. Dermoscopy aids in delineating the tumor margins, optimizing Mohs micrographic surgery (MMS) and traditional excision. It may also help to monitor therapeutic effects by detecting the disappearance of BCC patterns, the presence of residual tumor or recurrences. Dermoscopy may aid in the prediction of therapeutic responses to imiquimod, photodynamic therapy or vismodegib. UVFD and OSHMD appear to be valuable complementary diagnostic techniques for detecting BCC. UVFD seems to be particularly valuable for the detection of small tumors (<5 mm), facial lesions and nodular or non-pigmented BCC subtypes, while OSHMD is useful for the assessment of superficial and non-pigmented BCCs. Three-dimensional total-body photography enhances diagnostic precision but, so far, only when used in combination with traditional dermoscopy. Conclusions: Dermoscopy is valuable for margin delineation, therapy monitoring and differential diagnosis but can be inconclusive, which highlights the role of histopathology as the gold standard. Modifications in dermoscopy technique may further enhance its accuracy.

Amelanotic melanoma: Clinical presentation, diagnosis, and management

Amelanotic melanoma (AM) is a subtype of cutaneous melanoma with little or no pigment on visual or histopathologic examination and accounts for approximately 2% of melanoma cases. This uncommon variant is often misdiagnosed or diagnosed in late stages due to its variable clinical presentation and lack of established criteria for clinical diagnosis. AM often presents nonspecifically as a pink to red macule, papule, or dermal nodule; therefore, dermatoscopy and reflectance confocal microscopy are extremely helpful tools in the diagnosis of AM. Histopathologically, there is an attenuation or complete absence of melanin granules, and immunohistochemistry for melanocytic markers, such as S100, Melan-A, and HMB-45, may be necessary for accurate diagnosis. Like other types of melanomas, the Breslow depth, presence or absence of ulceration, and mitotic rate are necessary for diagnosis, staging, and management. The standard of treatment for AM includes surgical excision with margins based on staging with sentinel lymph node biopsy, if indicated. We present the clinical and histopathologic features, special techniques, differential diagnosis, and current management of AM.

Reflectance Confocal Microscopy and Dermoscopy for the Diagnosis of Solitary Hypopigmented Pink Lesions: A Narrative Review

Diagnosing solitary pink skin lesions poses a significant challenge due to the scarcity of specific clinical and dermoscopic criteria. Several benign lesions, such as cherry angioma, clear cell acanthoma, dermal nevus, keloid, hypertrophic scar, and Spitz nevus, often exhibit similar clinical and dermoscopic features. This similarity extends to some malignant lesions, including basal cell carcinoma, actinic keratosis, and amelanotic melanoma, making differentiation difficult. Recent studies highlight the enhanced diagnostic accuracy of reflectance confocal microscopy (RCM), which offers increased sensitivity and specificity compared to dermoscopy alone for diagnosing skin cancer. This study aims to summarize the application of dermoscopy and RCM in distinguishing between benign and malignant pinkish-reddish skin lesions. The integration of RCM with traditional dermoscopic techniques improves the ability to accurately identify and differentiate these lesions. However, it is crucial to note that for any suspicious lesions, a final diagnosis must be confirmed through surgical excision and histopathological evaluation. This comprehensive approach ensures accurate diagnosis and appropriate treatment, highlighting the importance of combining advanced imaging techniques in clinical practice.

Pediatric dermatofibromas: Truncal predominance in younger children

Pediatric dermatofibromas are considered rare in young children and have not been well characterized, often misdiagnosed clinically. We performed a retrospective case series of children younger than 18 years with histopathologically diagnosed dermatofibromas at our institutions and evaluated age at onset and diagnosis, sex, lesion location, and size, associated symptoms, change over time, and pre-biopsy diagnosis. Overall, dermatofibromas were most common on the back and chest (20/53; 38%), followed by the legs (15/53; 28%) and arms (12/53; 23%) with the most common pre-biopsy diagnosis of "cyst" (23/53; 43%), followed by dermatofibroma (16/53; 30%), and pilomatricoma (12/53; 23%). Our study reinforces previous findings of truncal predominance of pediatric dermatofibromas, different from adults.

Challenging Patterns of Atypical Dermatofibromas and Promising Diagnostic Tools for Differential Diagnosis of Malignant Lesions

Dermatofibroma (DF) or fibrous histiocytoma is one of the most frequent benign cutaneous soft-tissue lesions, characterized by a post-inflammatory tissue reaction associated with fibrosis of the dermis. Clinically DFs have a polymorphous clinical aspect from the solitary, firm, single nodules to multiple papules with a relatively smooth surface. However, multiple atypical clinicopathological variants of DFs have been reported and, therefore, clinical recognition may become challenging, leading to a more burdensome identification and sometimes to misdiagnosis. Dermoscopy is considered an important tool in DFs diagnosis, as it improves diagnostic accuracy for clinically amelanotic nodules. Although typical dermoscopic patterns are most frequently seen in clinical practice, there have also been some atypical variants described, mimicking some underlying recurrent and sometimes harmful skin afflictions. Usually, no treatment is required, although an appropriate work-up may be necessary in specific cases, such as in the presence of atypical variants or a history of recent changes. This narrative review's aim is to summarize current evidence regarding clinical presentation, positive and differential diagnosis of atypical dermatofibromas and also to raise awareness about the importance of specific characteristics of atypical variants to better differentiate them from malignant conditions.

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.

Dermoscopy of dermatofibromas: A new perspective

AIM

In dermoscopic studies on dermatofibromas, some publications divide the appearance of lesions into standardised patterns, and some publications classify the clinical appearance of the lesions by comparing them with existing dermatological lesions. This study aims to re-evaluate the dermoscopic findings and patterns of dermatofibromas from a different perspective.

MATERIALS AND METHODS

In this study, 142 lesions of 72 patients were evaluated dermoscopically and their patterns were schematised.

RESULTS

In our study, a total of 15 patterns consisting of main and sub-patterns were created. The most common patterns we detected were pattern 1 (1a: 13.4%, 1b: 8.5%), pattern 8 (8a: 10.6%, 8b: 4.2%) and pattern 2 (2a: 9.2%, 2b: 4.2%), respectively.

CONCLUSION

Patterns of DFs were reclassified while preserving basic patterns. We think that the new sub-patterns and schematisation with this study can contribute to a better understanding of DFs.

Hemosiderotic dermatofibroma mimicking melanoma: A case report and review of the literature

Hemosiderotic dermatofibroma (HDF) often mimics melanoma clinically. A definite diagnosis relies on histopathological evaluation and immunohistochemistry. As it can progress to aneurysmal dermatofibroma (ADF), complete excision is recommended.

Dermoscopic features of neoplasms in skin of color: A review

BACKGROUND

Dermoscopy is undoubtedly a useful tool to improve diagnostic accuracy and minimize the number of unnecessary biopsies. However, much of the literature on dermoscopy focuses on findings in lighter-skin phototypes, leaving potential gaps of knowledge regarding its use in skin of color (SoC). As the clinical applications of dermoscopy continue to increase, understanding dermoscopic patterns in SoC is imperative.

OBJECTIVE

This review discusses the literature on dermoscopic findings of neoplasms in SoC, highlighting unique and characteristic dermoscopic features.

METHODS

A literature review was performed using the PubMed database. Case reports, case series, case-control studies, and systematic reviews were included.

RESULTS

A total of 8326 studies were identified based on the selected search terms, and 41 were included in this review based on relevance.

CONCLUSION

There are specific dermoscopic characteristics in SoC for benign nevi, acral lentiginous melanoma, ethnic melanonychia, and dermatofibroma; however, there is a lack of published data about specific features of cutaneous melanoma, subungual melanoma, pigmented basal cell carcinoma, and pigmented squamous cell carcinoma in SoC. Because pigmented basal cell carcinoma, pigmented squamous cell carcinoma, ethnic melanonychia, and acral lentiginous melanoma are diagnosed at later stages in this population, it is important to understand their dermoscopic features. Further descriptive studies are needed to better characterize unique dermoscopic features in neoplasms in SoC.

Atrophic dermatofibroma in a young female: A rare entity

Introduction:

Atrophic dermatofibroma is a rare variant of dermatofibroma which is many times underdiagnosed.

Case Report:

We report a case report of a 29-year-old female who came to the dermatology department with black-colored lesions on the lower leg for the past 7 years. Histopathological examination revealed a non-encapsulated dermal tumor involving upper to deep reticular dermis and extending to superficial subcutis. There was epidermal hyperplasia, and at the center of the lesion a slight epidermal atrophy was present.

Discussion:

It is a commonly underdiagnosed variant of dermatofibroma. Histopathologically, this disorder presents as a decrease in at least 50% of the thickness of the dermis relative to the adjacent dermis. The case is rare and hence reported.

Eradication of Benign Skin Lesions of the Face by Voltaic Arc Dermabrasion (Atmospheric Plasma): Postoperative Pain Assessment by Thermal Infrared Imaging

Objectives

The face aging processes are associated with physiologic and biochemical alteration that produces wrinkles, skin pigmentation and benign growths. The aim of this study was to evaluate the clinical efficacy of voltaic arc dermabrasion with plasma to remove benign facial skin lesions.

Study Design

Voltaic arc dermabrasion plasma technique was used to remove the facial benign skin lesions. The study involved 45 patients (26 females;19 males) treated for benign facial skin lesions with voltaic arc dermabrasion also called plasma exeresis technique. The subjects age ranged between 43 and 65 years. The clinical observations and comparison of pretreatment and post-treatment photographs of the treated regions were performed by a joint examiner at each follow-up visit.

Results

During plasma irradiation, the average temperature of the skin was 290.3 ± 21.7 °C, while immediately after it was 90.6 ± 21.8 °C. Overall clinical improvement was 100% in six lesions with complete resolution of all lesions. Three patients observed a transient post-inflammatory pigmentation with a peak at 1 month after VAD treatment, gradually fading spontaneously over 2 to 3 months.

Conclusions

The voltaic arc dermabrasion technique (atmospheric plasma) should be considered for lesions, especially relatively superficial ones, and small lesions that are located on the face.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Dermatoscopic features of thin (≤2 mm Breslow thickness) vs. thick (>2 mm Breslow thickness) nodular melanoma and predictors of nodular melanoma versus nodular non-melanoma tumours: a multicentric collaborative study by the International Dermoscopy Society

BACKGROUND

Thin nodular melanoma (NM) often lacks conspicuous melanoma-specific dermatoscopic criteria and escapes clinical detection until it progresses to a thicker and more advanced tumour.

OBJECTIVE

To investigate the dermatoscopic morphology of thin (≤2 mm Breslow thickness) vs. thick (>2 mm) NM and to identify dermatoscopic predictors of its differential diagnosis from other nodular tumours.

METHODS

Retrospective, morphological case-control study, conducted on behalf of the International Dermoscopy Society. Dermatoscopic images of NM and other nodular tumours from 19 skin cancer centres worldwide were collected and analysed.

RESULTS

Overall, 254 tumours were collected (69 NM of Breslow thickness ≤2 mm, 96 NM >2 mm and 89 non-melanoma nodular lesions). Light brown coloration (50.7%) and irregular brown dots/globules (42.0%) were most frequently observed in ≤2 mm NMs. Multivariate analysis revealed that dotted vessels (3.4-fold), white shiny streaks (2.9-fold) and irregular blue structureless area (2.4-fold) were predictors for thinner NM compared to non-melanoma nodular tumours. Overall, irregular blue structureless area (3.4-fold), dotted vessels (4.6-fold) and serpentine vessels (1.9-fold) were predictors of all NM compared to non-melanoma nodular lesions.

LIMITATIONS

Absence of a centralized, consensus pathology review and cases selected form tertiary centres maybe not reflecting the broader community.

CONCLUSIONS

Our study sheds light into the dermatoscopic morphology of thin NM in comparison to thicker NM and could provide useful clues for its differential diagnosis from other non-melanoma nodular tumours.

Features of dermatofibroma in reflectance confocal microscopy

BACKGROUND

Dermatofibroma (DF) is a common benign skin lesion in a majority of cases located on the legs or upper limbs. The etiology of DF is still unclear.

OBJECTIVES

Reflectance confocal microscopy features of DF were described.

METHODS

Forty patients with DF diagnosis confirmed by dermoscopy were examined using reflectance confocal microscopy VivaScope 1500 from March 2018 to April 2019.

RESULTS

DF was more common in females (80%) than males (20%). Thirty-six lesions (90%) were located on the limbs while four (10%) were on the trunk. Dermoscopically, 18 lesions (45%) revealed typical features: central white area with a brown network in the periphery. Twenty-two DFs (55%) were found with a central white patch and globular-like structures, surrounded by a thin brown network. In reflectance confocal microscopy, all revealed a typical honeycombed pattern, although in some cases (30%), streaming was observed. In two lesions (5%) in epidermis, few dendritic cells were observed, and one DF revealed roundish pagetoid cells (2.5%). The dermoepidermal junction (DEJ) in all lesions was abounded in dilated vessels. The most common observable feature of DF was bright "rings" composed of monomorphic, regular cells surrounding dark dermal papillae. In five lesions (12.5%), rings were "double" because of exceptionally pigmented DF.

CONCLUSION

Reflectance confocal microscopy enables us to describe microscopic features of DF. There are four confocal microscopic features observable in each DF: in the epidermis, normal honeycombed pattern, sometimes with local streaming, in DEJ, edged papillae, bright rings, and dilated vessels.

Cellular Dermatofibroma: Clinicopathologic Review of 218 Cases of Cellular Dermatofibroma to Determine the Clinical Recurrence Rate

BACKGROUND

Cellular dermatofibromas, a variant of dermatofibroma, are reported to recur at rates of 26% to 50%.

OBJECTIVE

To determine whether there are distinct clinical or histological differences between cellular dermatofibromas that recur versus those that do not. To determine recurrence rates in a real-world clinical setting.

MATERIALS AND METHODS

A retrospective analysis of the medical records and skin biopsies of cellular dermatofibroma in the University of Utah Health system between December 2011 and 2016. Clinical and dermatopathological features were evaluated to find distinct differences between the cellular dermatofibromas that recurred compared with those that did not.

RESULTS

There were no significant differences in histology between the primary lesions in recurrent and nonrecurrent cases. One factor that seemed to be associated with a greater likelihood of recurrence was an initial lesion size greater than 1 cm. The authors' data suggest that if the margins are involved on initial biopsy, there is a 10% chance of recurrence. This percentage is far less than the 26% to 50% reported in the past literature.

CONCLUSION

If a patient presents with a cellular dermatofibroma larger than 1 cm and positive margins at initial biopsy, a careful discussion should be had between the provider and patient about the low risk of local recurrence.

Hemosiderotic Dermatofibroma: A Rare and Atypical Variant Capable of Clinically Resembling Melanoma

A dermatofibroma (DF) is a common, benign tumor composed of fibroblastic and histiocytic cells. DF presents clinically with several different reported variants. One rare variant is hemosiderotic DF (HDF), which is made up of small blood vessels and hemosiderin deposits. HDF can be indistinguishable, clinically, from melanoma, making the use of other pathological tools crucial in the diagnosis. We report the case of a 25-year-old male medical student from the Caribbean who presented to our clinic with a single asymptomatic pigmented cystic lesion on his left posterior calf. The cystic lesion was excised surgically. Histopathology examination of the excised mass revealed a moderately cellular, poorly demarcated, dermal, fibrohistiocytic proliferation. Pathology consultation confirmed a diagnosis of HDF.

Atrophic Dermatofibroma: A Comprehensive Literature Review

INTRODUCTION

An atrophic dermatofibroma is a benign fibrohistiocytic neoplasm. It typically presents as an asymptomatic patch with a depressed central area.

METHODS

The PubMed database was used to search the following words: atrophic, dermatofibroma, elastic and fibers. The relevant papers and their references generated by the search were reviewed. Images of the clinical and pathological features of two patients with an atrophic dermatofibroma are presented. In addition, a comprehensive review of the characteristics of this unique dermatofibroma is provided.

RESULTS

An atrophic dermatofibroma has been reported in 102 patients: 53 women, 11 men and 38 individuals whose gender was not provided. It typically appeared as an asymptomatic solitary patch with a central umbilication-most commonly on the shoulder or lower extremity or back-of women aged 48 years or older. Dermoscopy typically showed white scar-like patches; a patchy pigment network was also noted in some lesions. The pathology of an atrophic dermatofibroma has the same features that can be observed in a common fibrous dermatofibroma; there is acanthosis, basal layer hyperpigmentation, and induction of basal cell carcinoma-like features, hair follicle formation or sebaceous hyperplasia in the epidermis and a proliferation of spindle-shaped fibroblasts in the dermis. However, atrophic dermatofibromas also demonstrate depression of the central surface and thinning of the dermis; in many cases, the dermal atrophy is at least 50%. Elastic fibers are either decreased or absent. Similar to non-atrophic dermatofibromas, the immunoperoxidase profile of atrophic dermatofibromas is factor XIIIa-positive and cluster of differentiation 34 (CD34)-negative. The pathogenesis of atrophic dermatofibromas remains to be established.

CONCLUSION

An atrophic dermatofibroma is an uncommon benign variant of a dermatofibroma. The diagnosis can be suspected based on clinical features and dermatoscopic findings. A biopsy of the lesion will confirm the diagnosis. Periodic evaluation of the lesion site is a reasonable approach to the management of the residual tumor.

Hemosiderotic dermatofibroma mimicking melanoma in a 12-year-old boy: a case report

We report a case of hemosiderotic dermatofibroma presenting as a brown-black-colored nodule with peripheral extensions, which mimics melanoma. Histopathology showed completely benign features with no atypia or mitosis. Nodular extensions of childhood dermatofibromas may be related to the growth of the child not necessarily pointing to a malignant process.

Beyond classic dermoscopic patterns of dermatofibromas: a prospective research study

BACKGROUND

The usual stereotypical dermoscopic pattern associated with dermatofibromas is a pigment network and central white patch. However, this pattern may be difficult to diagnose in some variant cases. We aimed to describe dermoscopic patterns of dermatofibroma according to its histopathological subtypes, with special emphasis on new and rare dermoscopic features.

METHODS

This prospective study, which was conducted between September 2015 and May 2016 in the Department of Dermatology, University Hospital Hassan II, Fez, Morocco, included 100 cases of dermatofibroma confirmed on clinical and histological grounds. Each lesion was scored for classic, previously reported, or new dermoscopic features.

RESULTS

All our Moroccan patients had a dark skin phototype (Fitzpatrick scale types IV and V). A total of 14 morphological dermoscopic structures were distinguished, and 17 dermoscopic patterns were observed, with the most common pattern being the central white patch and peripheral pigment network (21%). New patterns observed in our study were a white ring around an ulceration (6%), a pigment network with a pigmented ring around follicular openings (2%), and a discreet peripheral network and starlike white patch (3%). A patchy network with white patches was significantly noted in atrophic dermatofibroma (p = 0.01); vascularization was described in both aneurysmal and hemosiderotic dermatofibromas (p = 0.002); and a white ring around an ulceration was noted in aneurysmal dermatofibroma (p < 0.001).

CONCLUSIONS

We provide a description of dermoscopic patterns of dermatofibroma according to its histological subtypes in a dark skin phototype, along with a new report of a white ring around an ulceration as a significant pattern in aneurysmal dermatofibroma.

Collision skin lesions-results of a multicenter study of the International Dermoscopy Society (IDS)

Background

Collision lesions as two independent and unrelated skin tumors often manifest an atypical morphology.

Objective

To determine the combinations of collision skin lesions (CSLs).

Methods

Twenty-one pigmented lesion clinics in nine countries included 77 histopathologically proven CSLs in this retrospective observational study.

Results

Seventy-seven CSLs from 75 patients (median age 59.8 years) were analyzed; 24.7% of CSLs were located on the head and neck area, 5.2% on the upper extremities, 48.1% on the trunk, and 11.7% on the lower extremities; 40.3% revealed a melanocytic component (median age 54.7 years), followed by 45.5% with a basal cell carcinoma (BCC) (median age 62.4 years) and 11.7% with a seborrheic keratosis (median age 64.7 years). CSLs with a BCC component were more often found on the head and neck area compared to tumors with a melanocytic component (34.3% versus 16.1%). Lesions with a melanocytic component were more often detected on the trunk compared to lesions with a BCC (64.5% versus 37.1%). Patients with CSLs with epidermal-epidermal cell combination were older than patients with epidermal-dermal cell combination (63 versus 55.2 years), were more often male than female (63% versus 43.3%), more often had the lesion on the head and neck area (32.6% versus 13.3%), and less often on the upper (2.2 % versus 10%) or lower extremities (8.7% versus 16.6%).

Conclusions

CSLs consist of a heterogeneous group of lesions of varying cell types. They are associated with advancing age and cumulative UV-exposure. CSLs manifest a complex morphology making it challenging to diagnose correctly.

Dermoscopic features of livedoid vasculopathy

Livedoid vasculopathy (atrophie blanche) is a form of thrombotic vasculopathy. It is characterized by small ulcers that become crusted, and heal after several months to produce white atrophic scars. The most commonly affected sites are the lower legs, in particular the dorsum of the feet and ankles. To date, the dermoscopic features of livedoid vasculopathy have not been clearly described in the literature. In this observational study, we sought to evaluate the dermoscopic patterns of livedoid vasculopathy and determine whether the dermoscopic features are associated with certain histopathological characteristics. We evaluated 9 patients with livedoid vasculopathy by dermoscopy. Skin biopsy specimens were stained with hematoxylin and eosin for histopathologic examination, and dermoscopic features were correlated with histopathological characteristics. In the majority of patients with livedoid vasculopathy, examination with dermoscopy revealed central crusted ulcers or ivory white areas associated with peripheral pigmentation in a reticular pattern. In addition, increased vascular structures including linear and glomerular vessels were found. On histopathological examination, the central ivory white areas correlated with dermal fibrosis, the reticular pigmentation corresponded to epidermal basal layer hyperpigmentation or melanin within melanophages in the dermal papillae, and the vascular structures correlated with dilatation and proliferation of capillaries in the upper dermis. In summary, the most common dermoscopic features of livedoid vasculopathy identified in this study were central crusted ulcers or ivory white scar-like areas associated with peripheral reticular pigmentation and increased vascular structures. The characterization of dermoscopic criteria for livedoid vasculopathy may improve the accuracy in the clinical diagnosis and follow-up of this disease.

An Atrophic Plaque with Arborizing Vessels

Dermatofibromas are a common finding in the daily clinical practice. Most lesions are found incidentally or because patients seek medical attention due to the aspect of the lesion. Rare variants of dermatofibroma such as aneurismatic or atrophic dermatofibroma can be encountered simultaneously; thus, these combined features may raise the possibility of other diagnoses to be considered. By providing diverse clinical and dermoscopic examples of dermatofibromas, we may prevent misdiagnosing these lesions. This case illustrates how two rare variants of dermatofibroma can coexist. Clinical presentation of dermatofibromas may vary greatly, and it is essential for dermatologists to recognize them clinically and dermoscopically before obtaining histopathological diagnosis.

Dermoscopic findings in a collision tumor composed of a dermatofibroma and a melanocytic nevus mimicking melanoma

Collision tumors consist of two different neoplasms occurring concurrently in the same lesion. This association has been described for both benign and malignant neoplasms that may be difficult to identify. Therefore, dermoscopy is a valuable tool to make a correct diagnosis. We report a very unusual collision tumor composed of both a dermatofibroma and a melanocytic nevus mimicking melanoma.

Hemosiderotic dermatofibroma: clinical and dermoscopic presentation mimicking melanoma

BACKGROUND

Dermatofibromas are common benign skin neoplasms.

MAIN OBSERVATIONS

The authors report the clinical, dermoscopic and histopathological features of a hemosiderotic dermatofibroma mimicking melanoma in an 85-year-old woman.

CONCLUSIONS

Atypical dermoscopic patterns may prove difficult to differentiate from melanocytic lesions, and because of its polymorphic, melanoma-like presentation, definite diagnosis of hemosiderotic dermatofibroma can be reached by histopathological examination.