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Skin Appendage Disorders Sep 2016Melanocytic nevi result from the proliferation of melanocytes at the dermal-epidermal junction and/or in the dermis and very rarely affect the nail matrix and bed....
Melanocytic nevi result from the proliferation of melanocytes at the dermal-epidermal junction and/or in the dermis and very rarely affect the nail matrix and bed. Intradermal nevi are tumors often diagnosed in routine clinical dermatological practice, with typical clinical and histopathologic aspects, and found in a wide variety of skin sites. We report a case of intradermal melanocytic nevus of the proximal nail fold with uncommon intraoperative gross findings and without involvement of the nail bed or matrix, showing intradermal component only, which draws our attention to the possible different presentation of melanocytic lesions. No description of intradermal nevi at this site has been reported in the literature so far.
PubMed: 27843922
DOI: 10.1159/000446246 -
Cancer Research May 2014Monitoring of atypical nevi is an important step in early detection of melanoma, a clinical imperative in preventing the disease progression. Current standard diagnosis...
Monitoring of atypical nevi is an important step in early detection of melanoma, a clinical imperative in preventing the disease progression. Current standard diagnosis is based on biopsy and histopathologic examination, a method that is invasive and highly dependent upon physician experience. In this work, we used a clinical multiphoton microscope to image in vivo and noninvasively melanocytic nevi at three different stages: common nevi without dysplastic changes, dysplastic nevi with structural and architectural atypia, and melanoma. We analyzed multiphoton microscopy (MPM) images corresponding to 15 lesions (five in each group) both qualitatively and quantitatively. For the qualitative analysis, we identified the morphologic features characteristic of each group. MPM images corresponding to dysplastic nevi and melanoma were compared with standard histopathology to determine correlations between tissue constituents and morphology and to evaluate whether standard histopathology criteria can be identified in the MPM images. Prominent qualitative correlations included the morphology of epidermal keratinocytes, the appearance of nests of nevus cells surrounded by collagen fibers, and the structure of the epidermal-dermal junction. For the quantitative analysis, we defined a numerical multiphoton melanoma index (MMI) based on three-dimensional in vivo image analysis that scores signals derived from two-photon excited fluorescence, second harmonic generation, and melanocyte morphology features on a continuous 9-point scale. Indices corresponding to common nevi (0-1), dysplastic nevi (1-4), and melanoma (5-8) were significantly different (P < 0.05), suggesting the potential of the method to distinguish between melanocytic nevi in vivo.
Topics: Diagnosis, Differential; Dysplastic Nevus Syndrome; Humans; Melanoma; Microscopy, Fluorescence, Multiphoton; Nevus, Pigmented
PubMed: 24686168
DOI: 10.1158/0008-5472.CAN-13-2582 -
Dermatology (Basel, Switzerland) 2010The mechanisms for the development of acquired melanocytic nevi remain mostly unclear. Here we report a case of eruptive nevi that developed after localized superficial... (Review)
Review
The mechanisms for the development of acquired melanocytic nevi remain mostly unclear. Here we report a case of eruptive nevi that developed after localized superficial trauma, and review the currently known cellular and triggering factors for acquired melanocytic nevi. A 66-year-old woman presented a linear arrangement of pigmented macules on her left calf that developed after a bloodless skin erosion on the same spot, resulting from friction with the lining of a ski boot. Dermatopathology identified multiple junctional proliferations of single or small nest-forming melanocytes with bridging, pigment incontinence and moderate cellular atypia. The number of a person's nevi correlates with age, race and genetics, but blistering diseases, scarring processes, light exposure and immunosuppression can contribute to nevocellular growth as well. Damaged keratinocytes and inflammatory cells can release growth factors inducing nevus cell proliferation, and immunosuppression could end cellular surveillance keeping preexisting nevus cell nests in check. We conclude that in predisposed patients, the trigger for eruptive nevi can be reduced to a simple localized minor trauma.
Topics: Aged; Female; Friction; Humans; Melanocytes; Nevus, Pigmented; Skin; Skin Neoplasms
PubMed: 20424415
DOI: 10.1159/000276983 -
Romanian Journal of Morphology and... 2017Conjunctival nevi are benign tumors, most often located at the nasal or temporal limbus, and rarely in the fornix or tarsus. The vast majority of caruncular tumors are...
Conjunctival nevi are benign tumors, most often located at the nasal or temporal limbus, and rarely in the fornix or tarsus. The vast majority of caruncular tumors are benign and only few are malignant. Most of the caruncular tumors (either benign or malignant) are nevi. We report a case of a 75-year-old female patient presenting caruncular atypical late-onset junctional nevus that clinically arose malignancy suspicion. Ophthalmologic macroscopic examination and slit lamp examination of the right eye were performed. Further blood tests were performed. Carunclectomy was performed two days after admission to hospital. Microscopy revealed the junctional localization, diffuse proliferation of the nevocytes. Immunoreactions with S100 and human melanoma black 45 (HMB45) antibodies were performed. Differential diagnosis of these lesions represents a great challenge. The greatest challenge represents the differential diagnosis between a benign tumor and a malignant life-threatening one, the malignant melanoma, especially with unusual presentation. The presence of a late-onset caruncular tumor with uncertain evolution requires excision biopsy to determine the diagnosis and to establish the best management.
Topics: Aged; Female; Humans; Nevus, Pigmented
PubMed: 29556641
DOI: No ID Found -
Journal of the American Academy of... Aug 2018A subset of melanomas carrying a B-Raf proto-oncogene, serine/threonine kinase gene (BRAF) V600E mutation, which is the most common targetable mutation in melanoma,...
BACKGROUND
A subset of melanomas carrying a B-Raf proto-oncogene, serine/threonine kinase gene (BRAF) V600E mutation, which is the most common targetable mutation in melanoma, arise in association with a melanocytic nevus that is also harboring a BRAF V600E mutation. The detailed histomorphologic characteristics of nevi positive for BRAF V600E have not been systematically documented.
OBJECTIVE
To identify histomorphologic features correlating with BRAF V600E status in nevi.
METHODS
We retrospectively identified melanocytic nevi from our laboratory reporting system. We performed a histomorphologic analysis and analysis of BRAF V600E expression by immunohistochemistry.
RESULTS
Thirteen nevi (14.8%) were negative and 76 (86.4%) were positive for BRAF V600E. The nevi positive for BRAF V600E were predominantly dermal (predominantly dermal growth in 55.3% of nevi positive for BRAF V600E and 15.4% of nevi negative for BRAF V600E [P = .01]) and showed a congenital growth pattern (congenital growth pattern in 51.3% of nevi positive for BRAF V600E and 15.4% of nevi negative for BRAF V600E [P = .02]). Compared with nevi negative for BRAF V600E, those that were positive for BRAF V600E often exhibited predominantly nested intraepidermal melanocytes, larger junctional nests, abrupt lateral circumscription, and larger cell size. Architectural disorder and inflammatory infiltrates were seen more often in nevi negative for BRAF V600E. BRAF sequencing of a subset of nevi confirmed the immunohistochemical results.
LIMITATIONS
Limitations include the study's retrospective design and the small sample size of nevi negative for BRAF V600E.
CONCLUSIONS
BRAF V600E is associated with distinct histomorphologic features in nevi. These features may contribute to improving the accuracy of classification and diagnosis of melanocytic neoplasms.
Topics: Adult; Cell Size; Diagnosis, Differential; Epidermis; Female; Gene Expression; Humans; Immunohistochemistry; Male; Melanocytes; Middle Aged; Mutation; Nevus; Nevus, Pigmented; Proto-Oncogene Mas; Proto-Oncogene Proteins B-raf; Retrospective Studies; Skin Neoplasms
PubMed: 29653212
DOI: 10.1016/j.jaad.2018.03.052 -
JAAD Case Reports Oct 2023
PubMed: 37766734
DOI: 10.1016/j.jdcr.2023.08.014 -
The British Journal of Dermatology Mar 2016Differentiating Spitz naevi from melanomas can be difficult both clinically and dermoscopically. Previous studies have reported the potential role of in vivo reflectance...
BACKGROUND
Differentiating Spitz naevi from melanomas can be difficult both clinically and dermoscopically. Previous studies have reported the potential role of in vivo reflectance confocal microscopy (RCM) in increasing diagnostic accuracy.
OBJECTIVES
To define RCM criteria that can differentiate 'false twins', namely Spitz naevi and melanomas sharing similar dermoscopic appearance.
METHODS
Lesions histopathologically diagnosed as Spitz naevi or melanomas were retrospectively retrieved. They were selected to cover all dermoscopic types and were put into couples sharing similar aspects. Lesions were classified into three main dermoscopic categories: globular and starburst pattern, spitzoid with dotted vessels, and multicomponent or aspecific pattern.
RESULTS
RCM findings revealed that striking cell pleomorphism within the epidermis, widespread atypical cells at the dermoepidermal junction and marked pleomorphism within nests were significantly associated with the diagnosis of melanoma, while spindled cells and peripheral clefting were found exclusively with and pathognomonic of Spitz naevi. Furthermore, the analysis of a dermoscopic subgroup highlights the importance of striking pleomorphism and spindled cells as clues to differentiate 'false twins' with globular or starburst patterns.
CONCLUSIONS
The current study highlights the role of RCM in discriminating 'false twins' of Spitz naevi and melanomas for lesions showing starburst and globular patterns on dermoscopy, whereas RCM is not useful in the other dermoscopic subgroups.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Dermoscopy; Diagnosis, Differential; Female; Humans; Male; Melanoma; Microscopy, Confocal; Middle Aged; Nevus, Epithelioid and Spindle Cell; Retrospective Studies; Skin Neoplasms; Young Adult
PubMed: 26554394
DOI: 10.1111/bjd.14286 -
Ocular Oncology and Pathology Dec 2017Retinal pigment epithelium (RPE) adenocarcinoma is a very rare malignant intraocular tumor. Herein we describe the histopathological features of RPE adenocarcinoma.
PURPOSE
Retinal pigment epithelium (RPE) adenocarcinoma is a very rare malignant intraocular tumor. Herein we describe the histopathological features of RPE adenocarcinoma.
CASE
A 36-year-old male was referred to our clinic because of floaters in his left eye. The initial diagnosis was malignant melanoma of the choroid. We resected the tumor and studied it histopathologically. The tumor tissue was investigated by light microscopy including immunohistochemistry using antibodies against S-100, HMB-45, EMA, and AE-1. Electron microscopic examination was also performed.
RESULTS
The tumor arose from the RPE and contained intracytoplasmic vacuoles and abundant melanin pigment. There were no nevoid cells in the choroid. A small part of the tumor cells showed tubular or lobular proliferation and choroidal invasion. Immunohistochemistry revealed positive staining in tumor cells with 4 antibodies. Tight cellular junctions specific to the RPE were confirmed by electron microscopy. The final diagnosis was RPE adenocarcinoma.
CONCLUSIONS
Most pigmented intraocular tumors are nevus and malignant melanomas of the choroid. It is easy to misdiagnose a RPE adenocarcinoma as a malignant melanoma of the choroid. An exact differential diagnosis should be determined by immunohistopathological and electron microscopic examination.
PubMed: 29344497
DOI: 10.1159/000477735 -
JAMA Dermatology Oct 2015Reflectance confocal microscopy (RCM) studies have been performed to identify criteria for diagnosis of skin neoplasms. However, RCM-based diagnosis is operator...
IMPORTANCE
Reflectance confocal microscopy (RCM) studies have been performed to identify criteria for diagnosis of skin neoplasms. However, RCM-based diagnosis is operator dependent. Hence, reproducibility of RCM criteria needs to be tested.
OBJECTIVE
To test interobserver reproducibility of recognition of previously published RCM descriptors and accuracy of RCM-based skin cancer diagnosis.
DESIGN, SETTING, AND PARTICIPANTS
Observational retrospective web-based study of a set of RCM images collected at a tertiary academic medical center. Nine dermatologists (6 of whom had ≥3 years of RCM experience) from 6 countries evaluated an RCM study set from 100 biopsy-proven lesions, including 55 melanocytic nevi, 20 melanomas, 15 basal cell carcinomas, 7 solar lentigines or seborrheic keratoses, and 3 actinic keratoses. Between June 15, 2010, and October 21, 2010, participanting dermatologists, blinded to histopathological diagnosis, evaluated 3 RCM mosaic images per lesion for the presence of predefined RCM descriptors.
MAIN OUTCOMES AND MEASURES
The main outcome was identification of RCM descriptors with fair to good interrater agreement (κ statistic, ≥0.3) and independent correlation with malignant vs benign diagnosis on discriminant analysis. Additional measures included sensitivity and specificity for diagnosis of malignant vs benign for each evaluator, for majority diagnosis (rendered by ≥5 of 9 evaluators), and for experienced vs recent RCM users.
RESULTS
Eight RCM descriptors showed fair to good reproducibility and were independently associated with a specific diagnosis. Of these, the presence of pagetoid cells, atypical cells at the dermal-epidermal junction, and irregular epidermal architecture were associated with melanoma. Aspecific junctional pattern, basaloid cords, and ulceration were associated with basal cell carcinomas. Ringed junctional pattern and dermal nests were associated with nevi. The mean sensitivity for the group of evaluators was 88.9% (range, 82.9%-100%), and the mean specificity was 79.3% (range, 69.2%-90.8%). Majority diagnosis showed sensitivity of 100% and specificity of 80.0%. Sensitivity was higher for experienced vs recent RCM users (91.0% vs. 84.8%), but specificity was similar (80.0% vs. 77.9%).
CONCLUSIONS AND RELEVANCE
The study highlights key RCM diagnostic criteria for melanoma and basal cell carcinoma that are reproducibly recognized among RCM users. Diagnostic accuracy increases with experience. The higher accuracy of majority diagnosis suggests that there is intrinsically more diagnostic information in RCM images than is currently used by individual evaluators.
Topics: Academic Medical Centers; Carcinoma, Basal Cell; Dermatology; Humans; Keratosis, Actinic; Melanoma; Microscopy, Confocal; Nevus, Pigmented; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Skin Neoplasms
PubMed: 25993262
DOI: 10.1001/jamadermatol.2015.0810 -
Human Pathology Feb 1995We report seven cases of a distinctive type of malignant melanoma characterized by a deceptively benign histological appearance with an architecture resembling that of...
We report seven cases of a distinctive type of malignant melanoma characterized by a deceptively benign histological appearance with an architecture resembling that of benign melanocytic nevi on scanning magnification. Two predominant architectural patterns were observed: a dome-shaped pattern (two specimens) and a verrucoid pattern (five specimens). The specimens with a dome-shaped pattern of growth were characterized by a smooth epidermal surface and a proliferation of epithelioid melanoma cells with an inconspicuous intraepidermal component resembling spindle and epithelioid cell nevi (Spitz nevi). Gradual diminution in the size of dermal nests toward the bases of the lesions simulating the maturation phenomenon of benign nevi was observed; however, the dermal organization in cords and strands of melanoma cells and the persistence of cellular atypia extending to the bases of the tumors allowed their recognition as malignant melanomas. On the other hand, the specimens with a verrucoid growth pattern consisted of broad, exophytic tumors with a verrucous epidermal surface resembling that of papillomatous dermal nevi but distinguished from them by the presence of a continuous proliferation of melanocytes along the dermal-epidermal junction and by confluent sheets of melanoma cells in the dermis without evidence of true maturation. Clinical follow-up showed local recurrence in three patients after intervals ranging from 5 months to 5 years and regional metastasis in one patient after 2 years. The lesions described here may constitute a serious pitfall for diagnosis because of their innocent silhouette on scanning magnification and their superficial resemblance to spindle and/or epithelioid cell nevi and benign verrucous melanocytic nevi. Proper attention to cytological detail and subtle architectural features will aid in recognizing this unusual variant of malignant melanoma.
Topics: Adult; Diagnosis, Differential; Female; Hamartoma; Humans; Male; Melanoma; Middle Aged; Nevus, Epithelioid and Spindle Cell; Nevus, Intradermal; Nevus, Pigmented; Skin Diseases; Skin Neoplasms
PubMed: 7860047
DOI: 10.1016/0046-8177(95)90034-9