Dermoscopy of uncommon skin tumours

A Review of Non-Invasive Skin Imaging in Merkel Cell Carcinoma: Diagnostic Utility and Clinical Implications

Background/Objectives: Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine malignancy characterized by its propensity for rapid growth and early regional and distant metastasis. Given its potentially lethal nature, accurate and timely diagnosis of MCC is of utmost importance. This review aims to describe non-invasive imaging methods that can serve as additional tools in the examination of MCC. Methods: In this narrative review, we describe the up-to-date spectrum of non-invasive skin-imaging methods that can serve as additional tools in the examination of MCC based on the available literature. Dermoscopy might enhance the clinical diagnosis of MCC, facilitate differentiation from other benign and malignant tumors, and help optimize the treatment plan. New imaging technologies might also provide useful information at a sub-macroscopic level and support clinical diagnosis. These techniques include high-frequency ultrasound (HFUS), reflectance confocal microscopy (RCM) and optical coherence tomography (OCT). Results: Clinically, MCC typically presents as a rapidly growing, red, purple or skin-colored painless and firm nodule. Diagnosis is usually established with histopathological assessment and immunohistochemistry. However, dermoscopy and new imaging technologies might enhance the clinical diagnosis of MCC, facilitate differentiation from other benign and malignant tumors, and help optimize the treatment plan.

Extraocular cutaneous sebaceous carcinoma in a patient with Muir-Torre syndrome: special emphasis on histologic and dermoscopic features

Cutaneous sebaceous carcinoma (CSC) can be classified into periocular and extraocular and can occur as part of Muir-Torre syndrome. It is usually a pink-red or yellow solitary nodule, mainly located in the head and neck region. According to the literature, dermoscopy is characterized in most cases by a yellow color, polymorphic vessels, and ulceration. We performed a review of the literature, and we found 14 papers describing the dermoscopic features of 33 sebaceous carcinomas, to which we added a case that we have recently observed. Compared to the data of the literature and in particular to the latest published reviews, we found that milky-red areas are frequently observed in CSC (47% of the cases) and can be added to the main dermoscopic features for the diagnosis. In our case, histology showed some features that were consistent with a CSC with a secretory pattern, and other features that were instead consistent with a non-secretory pattern. This was probably due to the fact that the lesion we observed was a moderately differentiated and not well-differentiated CSC. The presence of a CSC should always alert the clinician to the possible association with Muir-Torre syndrome, and immunohistochemistry for mismatch repair gene defects can help in the diagnostic pathway.

Minimally Invasive Plasma Device Management of Multiple Benign Skin Cancers Associated with Rare Genodermatoses-Case Series and Review of the Therapeutic Methods

Background: Non-melanocytic benign skin tumours encompass a diverse group of lesions, classified based on their cellular origin, such as epidermal, vascular, fibrous, neural, muscle, and adnexal tumours. Though they often reveal solitary lesions, multiple skin tumours focus on genodermatoses. Each syndrome exhibits distinct clinical characteristics and potential complications, including cutaneous and extra-cutaneous malignancies, some of which are potentially life-threatening. Diagnosing genetic syndromes is complex and requires numerous histopathological and immunohistochemistry tests due to similarities between the adnexal tumours and basal cell carcinoma upon pathology. Methods: To illustrate the clinical practice, we conducted a retrospective case study that included eleven patients with genodermatoses referred to a tertiary dermatology clinic from September 2018 to April 2024. We have also conducted a research study on available treatment modalities in this setting. Results: Five patients with excellent aesthetic results were treated using a recently approved FDA plasma device. After searching SCOPUS and PubMed database records, we assessed 96 original articles to present current knowledge regarding the dermato-surgical approach. Conclusions: Multiple skin tumours, especially on the face, may significantly affect patients' quality of life and have psychological consequences. An appropriate treatment selection tailored to the patient's needs should be provided. There is no standardised treatment for multiple benign tumours in genodermatoses, and selected methods with varying efficacy are employed. We presented the utility of a new plasma device in these settings.

Dermoscopic characteristics of Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive, cutaneous tumour with high mortality and frequently delayed diagnosis. Clinically, it often manifests as a rapidly growing erythematous to purple nodule usually located on the lower extremities or face and scalp of elderly patients. There is limited available data on the dermoscopic findings of MCC, and there are no specific features that can be used to definitively diagnose MCC.

AIM OF THE STUDY

Here, we aimed to summarize existing published literature on dermatoscopic and reflectance confocal microscopy (RCM) features of MCC.

MATERIALS AND METHODS

To find relevant studies, we searched the PubMed and Scopus databases from inception to April 12, 2023. Our goal was to identify all pertinent research that had been written in English. The following search strategy was employed: (" dermoscopy" OR " dermatoscopy" OR " videodermoscopy" OR " videodermatoscopy" OR " reflectance confocal microscopy") AND " Merkel cell carcinoma". Two dermatologists, DK and GE, evaluated the titles and abstracts separately for eligibility. For inclusion, only works written in English were taken into account.

RESULTS

In total 16 articles were retrieved (68 cases). The main dermoscopic findings of MCC are a polymorphous vascular pattern including linear irregular, arborizing, glomerular, and dotted vessels on a milky red background, with shiny or non-shiny white areas. Pigmentation was lacking in all cases. The RCM images showed a thin and disarranged epidermis, and small hypo-reflective cells that resembled lymphocytes arranged in solid aggregates outlined by fibrous tissue in the dermis. Additionally, there were larger polymorphic hyper-reflective cells that likely represented highly proliferative cells.

CONCLUSION

Dermoscopic findings of MCC may play a valuable role in evaluating MCC, aiding in the early detection and differentiation from other skin lesions. Further prospective case-control studies are needed to validate these results.

Dermatitis Artefacta: A Retrospective Descriptive Study on 46 Patients

INTRODUCTION

Self-induced dermatoses are self-inflicted skin lesions, whose occurrence patient denies responsibility for.

OBJECTIVES

The aim of this study was to retrospectively investigate all the clinical records of dermatitis artefacta (DA) in order to put special focus on: a) epidemiological aspects; b) location, shape and additional features of the lesions; c) availability of psychiatric details in the records.

METHODS

A retrospective observational descriptive study on 46 patients affected by dermatitis artefacta was conducted from January 2015 to March 2021. The only inclusion criterion was clinical or histological diagnosis of DA in patients for which we had clinical images.

RESULTS

The most frequent type of lesions were erosions/excoriations and ulcers (14/46, 30.4% and 13/46, 28.3% respectively) followed by ecchymoses (9/46, 19.5%), vasculitis-like lesions (5/46, 10.9%), crusted plaques (3/46, 6.5%), scales (1/46, 2.2%) and erythema (1/46, 2.2%). Thirty-three percent of the medical records generically referred to the presence of psychiatric disorder, but none of them included a specific psychiatric diagnosis.

CONCLUSIONS

In our study the main dermatologic lesions observed in DA were represented by excoriations and ulcers and that the shape and location of the lesions are essential for a correct diagnosis.

Sebaceous Neoplasms

Sebaceous neoplasms describe a group of tumors with sebaceous differentiation commonly seen in lesions located primarily in the face and neck. The majority of these lesions are benign, while malignant neoplasms with sebaceous differentiation are uncommon. Sebaceous tumors present a strong association with the Muir-Torre Syndrome. Patients suspected with this syndrome should undergo neoplasm excision, followed by histopathologic and additional immunohistochemistry and genetics examinations. Clinical and dermoscopic features of the sebaceous neoplasms, as well as management procedures collected from the literature analysis regarding sebaceous carcinoma, sebaceoma/sebaceous adenoma, and sebaceous hyperplasia are described in the current review. A special note is made for describing the Muir-Torre Syndrome in patients presenting multiple sebaceous tumors.

Diagnosis and treatment of Merkel cell carcinoma: European consensus-based interdisciplinary guideline - Update 2022

Merkel cell carcinoma (MCC) is a rare skin cancer, accounting for less than 1% of all cutaneous malignancies. It is found predominantly in white populations and risk factors include advanced age, ultraviolet exposure, male sex, immunosuppression, such as AIDS/HIV infection, haematological malignancies or solid organ transplantation, and Merkel cell polyomavirus infection. MCC is an aggressive tumour with 26% of cases presenting lymph node involvement at diagnosis and 8% with distant metastases. Five-year overall survival rates range between 48% and 63%. Two subsets of MCC have been characterised with distinct molecular pathogenetic pathways: ultraviolet-induced MCC versus virus-positive MCC, which carries a better prognosis. In both subtypes, there are alterations in the retinoblastoma protein and p53 gene structure and function. MCC typically manifests as a red nodule or plaque with fast growth, most commonly on sun exposed areas. Histopathology (small-cell neuroendocrine appearance) and immunohistochemistry (CK20 positivity and TTF-1 negativity) confirm the diagnosis. The current staging systems are the American Joint Committee on Cancer/Union for international Cancer control 8th edition. Baseline whole body imaging is encouraged to rule out regional and distant metastasis. For localised MCC, first-line treatment is surgical excision with postoperative margin assessment followed by adjuvant radiation therapy (RT). Sentinel lymph node biopsy is recommended in all patients with MCC without clinically detectable lymph nodes or distant metastasis. Adjuvant RT alone, eventually combined with complete lymph nodes dissection is proposed in case of micrometastatic nodal involvement. In case of macroscopic nodal involvement, the standard of care is complete lymph nodes dissection potentially followed by post-operative RT. Immunotherapy with anti-PD-(L)1 antibodies should be offered as first-line systemic treatment in advanced MCC. Chemotherapy can be used when patients fail to respond or are intolerant for anti-PD-(L)1 immunotherapy or clinical trials.

Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare and extremely aggressive neuroendocrine carcinoma of the skin, with increasing incidence worldwide. This review intends to propose a comprehensive evaluation of MCC epidemiology, clinical features, pathogenetic mechanisms, diagnosis, and therapies. A section is dedicated to immunological aspects and another to the involvement of angiogenesis and angiogenic growth factors in MCC progression, proposing novel diagnostic and therapeutic approaches. Advanced MCC tumors have been treated with immune checkpoint inhibitors with effective results. Therefore, the state of art of this immunotherapy is also examined, reporting on the most recent clinical trials in the field. We conclude by underlining the achievements in the understanding of MCC pathology and indicating the present needs for effective diagnosis and therapeutic management of the disease.

Primary and secondary cutaneous angiosarcoma: Distinctive clinical, pathological and molecular features

Angiosarcomas are ubiquitous neoplasms involving both cutaneous and soft tissue and visceral locations. Accumulating biomolecular evidences suggest that cutaneous angiosarcomas are distinctive entities with molecular, clinical and pathological peculiarities. Despite several ongoing clinical trials with promising therapeutic agents, the prognosis of cutaneous angiosarcomas is dismal and survival still rely on early diagnosis and surgery. An accurate diagnosis and the knowledge of the underlying molecular landscape are therefore essential to improve the prognosis. We detail the molecular, clinical, dermoscopic, morphological and prognostic features of cutaneous angiosarcoma. Although the molecular landscape of cutaneous angiosarcoma is not completely understood, accumulating evidences suggest that there are characteristic molecular alterations including dysregulation of angiogenesis and several complex molecular pathways. Secondary cutaneous angiosarcomas, arising in correlation with chronic lymphedema and ionizing radiation, have different molecular hallmarks, which are also leading to the first diagnostic applications. The diagnosis of cutaneous angiosarcoma may be challenging, as well-differentiated forms can be hard to distinguish from benign and low-grade vascular neoplasms, while poorly differentiated forms can be easily confounded with other non-vascular high-grade neoplasms. An accurate and early diagnosis, which is mandatory to ensure the best survival for the patients, is mainly based on morphological hallmarks.

Dermoscopy of Melanoma and Non-melanoma Skin Cancers

Dermoscopy is a widely used non-invasive technique for diagnosing skin tumors. In melanocytic tumors, e.g., melanoma and basal cell carcinoma (BCC), the effectiveness of dermoscopic examination has been fully established over the past two decades. Moreover, dermoscopy has been used to diagnose non-melanocytic tumors. Here, we review novel findings from recent reports concerning dermoscopy of melanoma and non-melanoma skin cancers including BCC, sebaceous carcinoma, actinic keratosis, Bowen's disease, squamous cell carcinoma (SCC), Merkel cell carcinoma (MCC), extramammary Paget's disease (EMPD), and angiosarcoma.

Desmoplastic trichilemmoma of the scalp: case report and literature review of immunohistochemical staining features

Desmoplastic trichilemmoma (DT) of the scalp is a rare disease. In this report, we describe a 67-year-old man who had a small papule lesion around the hairline of the left scalp for more than 40 years. The lesion had rapidly grown to become a solitary, round, 15-mm neoplasm within 6 months. Histopathological examination showed that the mass was composed of a peripheral layer of columnar cells with nuclear palisading resembling the outer root sheath; the mass was surrounded by a thickened glassy basement membrane. The stroma in the center of the mass displayed solid, hyaline degeneration and an eosinophilic pattern, streaked with epithelial cords or islands. Immunohistochemical evaluation showed diastase-resistant, periodic acid–Schiff-positive desmoplastic stroma at the center, and Ber-EP4-negative tumor cells (CD34-positive focally and Bcl-2-positive at the periphery). The tumor was completely resected, and no recurrence occurred during the follow-up period. In this report, we also summarize immunohistochemical features from previous reports of DT, facilitating differential diagnosis of DT from some invasive skin tumors.

Dermoscopy of Adnexal Tumors

Cutaneous adnexal tumors include lesions with apocrine, eccrine, follicular, sebaceous, and mixed differentiation. Most are benign and sporadic, although malignant forms are occasionally observed and some cases develop in the setting of inherited syndromes. These tumors often cause immense diagnostic difficulty. Dermoscopy is a noninvasive technique that has greatly improved the diagnostic accuracy of different skin lesions, including these tumors. We provide a review of the literature on the dermoscopic structures and patterns associated with adnexal tumors. Most patterns associated with this kind of tumor are nonspecific and are observed in other nonadnexal tumors, especially in basal cell carcinomas.

Dermoscopy in a lymphangiosarcoma of Stewart–Treves syndrome

Stewart–Treves syndrome is a rare invasive lymphangiosarcoma linked with chronic lymphedema after mastectomy for breast cancer. Given the aggressive nature of the tumor, preventative measures and early diagnosis are important. This case is the first dermoscopic description of the lymphangiosarcoma of Stewart–Treves syndrome; it shares similar dermoscopic findings with angiosarcoma of the scalp after irradiation, with findings of a pink-white background, white lines and a combination of red, blue and black structureless areas containing red dots and globules. The lack of conspicuous lacunae make dermoscopy useful for ruling out other differentials such as benign vascular proliferations. Color heterogeneity and vascularization in dermoscopy might inform the clinician of a high percentage of tumor cells on histology.

Dermoscopy features of atypical fibroxanthoma: A multicenter study of the International Dermoscopy Society

BACKGROUND/OBJECTIVES

Little is known about the dermoscopic features of atypical fibroxanthoma.

METHODS

This was a case-control study. Atypical fibroxanthoma lesions were compared with a control group with non-melanoma skin cancer.

RESULTS

Altogether 40 atypical fibroxanthoma were collected. Most developed in men (93%), appearing mainly as nodular (63%), amelanotic (93%) and ulcerated (78%) lesions. Most lesions were located on the scalp (55%) and the ears (13%). Dermoscopically, most atypical fibroxanthoma displayed red (83%) and white (70%) structureless areas and irregular linear vessels (43%). A series of features achieved statistical significance when comparing atypical fibroxanthoma with non-melanoma skin cancer. The presence of red and white structureless areas and white lines, and the absence of yellowish-white opaque scales, hairpin vessels and arborising vessels were predictive of atypical fibroxanthoma in univariate analysis. However, when squamous cell carcinoma was excluded from the analysis, none of the criteria achieved statistical significance. When basal cell carcinoma was excluded, three variables achieved statistical significance in predicting atypical fibroxanthoma: red, structureless areas, the absence of opaque yellowish-white scales and absence of white circles.

CONCLUSIONS

Atypical fibroxanthomas seem to be barely distinguishable from basal cell carcinoma dermoscopically, but they are more easily distinguishable from a well to moderately differentiated squamous cell carcinoma. A histopathological examination is needed for the final diagnosis.

The limitations of dermoscopy: false-positive and false-negative tumours

Dermoscopy has been documented to increase the diagnostic accuracy of clinicians evaluating skin tumours, improving their ability to detect skin cancer and better recognize benign moles. However, dermoscopically 'false-positive' and 'false-negative' tumours do exist. False-positive diagnosis usually leads to unnecessary excisions. False-negative diagnosis is much more dangerous, as it might result in overlooking a cancer, with severe undesirable consequences for the patient and the physician. Therefore, management strategies should mainly focus on addressing the risk of dermoscopically false-negative tumours. The most frequent benign tumours that might acquire dermatoscopic characteristics suggestive of malignancy are seborrhoeic keratosis (SK), including solar lentigo, melanoacanthoma, irritated, clonal and regressive SK, angioma (mainly thrombosed angioma and angiokeratoma), dermatofibroma, benign adnexal tumours and naevi (Clark, Spitz, recurrent, combined, sclerosing). The most useful clues to recognize these tumours are the following: solar lentigo - broad network; melanoacanthoma - sharp border; irritated SK - regularly distributed white perivascular halos; clonal SK - classic SK criteria; regressive SK - remnants of SK; targetoid haemosiderotic haemangioma - dark centre and reddish periphery; thrombosed angioma - sharp demarcation; angiokeratoma - dark lacunae; atypical dermatofibromas - palpation; follicular tumours - white colour; sebaceous tumours - yellow colour; Clark naevi - clinical context; Spitz/Reed naevi - age; combined naevi - blue central area; recurrent naevi - pigmentation within the scar; sclerosing naevi - age and location on the upper back; blue naevi - history. Malignant tumours that might mimic benign ones and escape detection are melanoma (in situ, nevoid, spitzoid, verrucous, regressive, amelanotic), squamous cell carcinoma (mainly well-differentiated variants) and rarely basal cell carcinoma (non-pigmented variants). The most useful clues to recognize the peculiar melanoma subtypes are as follows: melanoma in situ - irregular hyperpigmented areas; nevoid melanoma - history of growth; spitzoid melanoma - age; verrucous melanoma - blue-black sign; regressive melanoma - peppering or scar-like depigmentation; amelanotic melanoma - pink colour, linear irregular vessels, dotted vessels. In this article, we summarized the most frequent dermoscopic variations of common skin tumours that are often misinterpreted, aiming to assist clinicians to reduce the number of false diagnoses.

Dermoscopic features distinctive for extraocular sebaceous carcinoma

We examined dermoscopic features of three cases of extraocular sebaceous carcinoma and reviewed the literatures. The yellowish structures, polymorphous vessels and ulceration were common findings in our cases and all cases of the previous reports. The appearance of whitish-pink areas has not been described previously. Our results suggested that the combination of four dermoscopic features, whitish-pink areas, yellowish structures, polymorphous vessels and ulceration might be distinctive in extraocular sebaceous carcinoma.

Osseous choristoma of the tongue: A case report with dermoscopic study

Osseous choristomas are rare benign lesions characterized by ectopic bone formation in the soft tissue of the head and neck region. Dermoscopy visualizes the morphological characteristics that are not observable by the naked eye, and may be used for the evaluation of calcification under the skin. The present study reports a case of an osseous choristoma arising in the tongue, and reveals the dermoscopic features of osseous choristoma from a surgical specimen. A 7-year-old boy was referred to the Department of Dentistry and Oral Surgery, with an asymptomatic pedunculated mass in the tongue. The lesion was removed completely with the adjacent normal tissue under general anesthesia. Dermoscopy of the surgical specimen revealed the hypovascular and homogeneous pattern of the lesion with round extruded whitish material. Based on dermoscopic findings, the presence of calcified hard tissue in the submucosa was verified by the dermatologist. Radiographic examination of the surgical specimen revealed the lesion contained a radiopaque trabeculated mass. Histologically, the lesion contained an osseous tissue, and the pathological diagnosis of osseous choristoma was made following consideration of the ectopic bony tissues that were localized away from the maxillo-mandibular bone. The postoperative course was uneventful with no signs of recurrence during the 36 months following surgery. To the best of the author's knowledge, this is the first report of evaluation of osseous choristoma using dermoscopy. The observation indicates the usefulness of dermoscopy for the diagnosis of oral ossified lesion in oral soft tissue.

Accuracy of dermatoscopy for the diagnosis of nonpigmented cancers of the skin

BACKGROUND

Nonpigmented skin cancer is common, and diagnosis with the unaided eye is error prone.

OBJECTIVE

To investigate whether dermatoscopy improves the diagnostic accuracy for nonpigmented (amelanotic) cutaneous neoplasms.

METHODS

We collected a sample of 2072 benign and malignant neoplastic lesions and inflammatory conditions and presented close-up images taken with and without dermatoscopy to 95 examiners with different levels of experience.

RESULTS

The area under the curve was significantly higher with than without dermatoscopy (0.68 vs 0.64, P < .001). Among 51 possible diagnoses, the correct diagnosis was selected in 33.1% of cases with and 26.4% of cases without dermatoscopy (P < .001). For experts, the frequencies of correct specific diagnoses of a malignant lesion improved from 40.2% without to 51.3% with dermatoscopy. For all malignant neoplasms combined, the frequencies of appropriate management strategies increased from 78.1% without to 82.5% with dermatoscopy.

LIMITATIONS

The study deviated from a real-life clinical setting and was potentially affected by verification and selection bias.

CONCLUSIONS

Dermatoscopy improves the diagnosis and management of nonpigmented skin cancer and should be used as an adjunct to examination with the unaided eye.

Dermoscopic assessment of vascular structures in solitary small pink lesions-differentiating between good and evil

The diagnosis of a single small pink papule poses a real challenge to the clinician, as the differential diagnosis of such lesions includes benign entities such as a neurofibroma or hemangioma, as well as aggressive and potentially fatal skin malignancies such as amelanotic melanoma or Merkel cell carcinoma (MCC). The absence of a benign vascular pattern and the presence of atypical vascular features under dermoscopy direct the clinician to proceed to histologic evaluation in order to rule out a malignant process in such lesions. The diagnosis of MCC is particularly problematic, given that this tumor usually lacks specific clinical diagnostic features. Low clinical suspicion for MCC may result in delayed diagnosis and poor outcomes. The dermoscopic features of MCC are also non-specific, most commonly including milky-red areas and linear irregular vessels. We report a patient who presented with two discrete pink papules on different digits that appeared three years apart. Dermoscopy helped to diagnose a harmless hemangioma in the first lesion, and a MCC in the latter. The malignant tumor was diagnosed and excised expeditiously, with no evidence of metastatic spread.

Dermoscopy of Malignant Skin Tumours: What's New?

Dermoscopy represents a new and effective tool that assists dermatologists in improving the accuracy of clinical diagnosis in onco-dermatology. The aim of this article is to provide an overview of the latest and important dermoscopic progress and observations in this ever-evolving field of dermatology.

Usefulness of Dermoscopy in the Differential Diagnosis of Ruptured and Unruptured Epidermal Cysts

BACKGROUND

An epidermal cyst is a common keratin-filled epithelial-lined cyst. The treatment of choice for epidermal cysts is surgical excision. If the cyst becomes ruptured, incision and drainage with oral antibiotic therapy or intralesional steroid injection are required.

OBJECTIVE

To analyze the dermoscopic features that can differentiate between ruptured and unruptured epidermal cysts.

METHODS

The clinical and dermoscopic features of the pathologically confirmed epidermal cysts of two subgroups of 38 patients, 20 with unruptured cysts and 18 with ruptured cysts, were reviewed.

RESULTS

With regard to the dermoscopic features, an ivory- white background color and punctum were commonly found in both groups (p>0.05). The unruptured-cyst group showed higher frequencies of pore sign (p<0.05), blue-white veil (p>0.05), no vascular structure, and arborizing telangiectasia (p<0.05), but the ruptured-cyst group usually had red lacunae (p>0.05) and peripheral linear branched vessels (with an erythematous rim) (p<0.05).

CONCLUSION

Dermoscopy is helpful in differentiating between ruptured and unruptured epidermal cysts.

The use of dermatoscopy in diagnosis and therapy of nonmelanocytic skin cancer

Today, dermatoscopy is an integral part of every clinical skin examination, as it markedly enhances the early detection of melanocytic and nonmelanocytic skin cancer (NMSC) compared to naked-eye inspection. Besides its diagnostic use, this noninvasive method is increasingly important in the selection of as well as the response assessment to various therapies used for NMSC, including basal cell carcinoma, actinic keratoses, squamous cell carcinoma, and also rare tumors such as Merkel cell carcinoma, angiosarcoma, or dermatofibrosarcoma protuberans. Thus, dermatoscopy is a valid tool for the preoperative assessment of tumor margins in basal cell carcinoma, but also for follow-up of actinic keratoses after topical treatment. The present article presents an overview on the use of dermatoscopy in the diagnosis and therapy of various types of NMSC.

Lesion presenting with a “blue amber” pattern

Atypical fibroxanthoma (AFX) is a spindle cell neoplasm with low metastatic potential but high tendency to recur after surgery. Because of the rarity of this lesion and its aspecific clinical features, AFX could be easily misdiagnosed and undertreated by many clinicians who encounter them. Dermoscopy represents a valuable tool for easily assessing skin lesions, even though histological examination is required for final diagnosis. We report a case of a cheek lesion with dermoscopic “blue amber pattern”, easily recognisable and not observed in others skin tumours, which could represent an additional feature useful in differentiating this tumour from other skin neoplasms.

Pale halo surrounding a homogeneous bluish-purplish central area: dermoscopic clue for eccrine hidrocystoma

Eccrine hidrocystomas are benign tumors of the sweat glands that arise from cystic dilatation of the excretory sweat duct. Exact diagnosis requires biopsy and histopathologic examination, from which arises risk of scarring. Dermoscopy could be a useful tool in diagnosing eccrine hidrocystomas. Herein we aim to present dermoscopic features in three female patients with multiple lesions on the face consistent with eccrine hidrocystomas.

Dermoscopy in the diagnosis and management of basal cell carcinoma

The dermoscopic findings of basal cell carcinoma (BCC) were first described more than a decade ago and the list of BCC-related criteria has been several times updated and enriched. Today, the dermatoscope is considered the key tool for the diagnosis of BCC, since it allows its early detection and enables its discrimination from other pigmented and nonpigmented skin tumors. The dermoscopic pattern of BCC results from several combinations of well-known BCC criteria, depending on several factors, including histopathologic subtype, location, gender, age and pigmentary trait. In addition, recent evidence highlighted that dermoscopy is also useful in the management of BCC, since it provides information on the tumor subtype, the presence of pigmentation or ulceration and the response to nonablative treatments.

Trichilemmoma in continuity with pigmented basal cell carcinoma; with dermatoscopy and dermatopathology

A case of trichilemmoma in continuity with a pigmented basal cell carcinoma is presented with dermatoscopy and dermatopathology. The distinction between the two lesions was evident dermatoscopically and was confirmed dermatopathologically. While trichilemmoma has been reported in association with basal cell carcinoma and dermatoscopy images of four previous cases of trichilemmoma have been published, no previous dermatoscopy image has been published of trichilemmoma associated with basal cell carcinoma.

The clinical and dermoscopic features of invasive cutaneous squamous cell carcinoma depend on the histopathological grade of differentiation

BACKGROUND

Little is known about the variability of the dermoscopic criteria of squamous cell carcinoma (SCC) according to the histopathological differentiation grade.

OBJECTIVES

To evaluate whether specific dermoscopic criteria can predict the diagnosis of poorly differentiated SCC compared with well- and moderately differentiated SCC.

METHODS

Clinical and dermoscopic images of SCCs were retrospectively evaluated for the presence of predefined criteria. Univariate and adjusted odds ratios were calculated. Discriminant functions were used to plot receiver-operator characteristic curves.

RESULTS

Of 143 SCCs included, 48 (33·5%) were well differentiated, 45 (31·5%) were moderately differentiated and 50 (35·0%) were poorly differentiated. Flat tumours had a fourfold increased probability of being poorly differentiated. Dermoscopically, the presence of a predominantly red colour posed a 13-fold possibility of poor differentiation, whereas a predominantly white and white-yellow colour decreased the odds of poorly differentiated SCC by 97% each. The presence of vessels in more than 50% of the tumour's surface, a diffuse distribution of vessels and bleeding were significantly associated with poor differentiation, while scale/keratin was a potent predictor of well- or moderately differentiated tumours.

CONCLUSIONS

Dermoscopy may be regarded as a reliable preoperative tool to distinguish poorly from well- and moderately differentiated SCC. Given that poor differentiation of SCC represents an independent risk factor for recurrence, metastasis and disease-specific death, identifying poorly differentiated tumours in vivo may enhance their appropriate management.

Photoletter to the editor: Collision tumor of melanoma and atypical fibroxanthoma of the scalp

Several combinations of different skin tumors occuring one adjacent to the other or even in a single lesion have been described up to date. Collision tumors involving atypical fibroxanthoma and melanoma are extremely uncommon. Herein we present a case of melanoma associated with AFX and discuss on the usefulness of dermoscopy in the clinical diagnosis of collision tumors.