Cell Nevus Research Articles

PRAME Immunostaining in BAP-1-Inactivated Melanocytic Tumors: Unraveling Diagnostic Complexity and Exploring Germline Mutation Associations

Background: Cutaneous melanocytic tumors with BAP-1 inactivation (BIMTs), linked to mutations in the BAP-1 gene, present diagnostic challenges due to their morphological similarities with other melanocytic lesions. The search for reliable diagnostic markers, including PRAME, holds potential to significantly improve the accuracy of differential diagnoses. Methods: A retrospective analysis of 32 BIMTs from 25 patients, collected between 2018 and 2022, involved histologic examination and immunostaining for BAP-1 and PRAME. Results: Positive PRAME expression, defined as diffuse staining in at least 75% of nevic cells, was observed in 19% of cases. Variations in PRAME expression patterns were noted, particularly in biphasic lesions and those associated with germline BAP-1 mutations. Conclusions: The diagnostic complexities of BIMTs necessitate a comprehensive diagnostic strategy. While BAP-1 immunostaining remains pivotal, this study explored PRAME as a potential adjunctive diagnostic tool. PRAME antibody shows highly variable expression in BIMTs, limiting its utility as a supportive tool for the differential diagnosis with melanomas, especially in patients with biphasic lesions and germline mutations in BAP-1.

Clinicopathologic features and new factors affecting constitution of eyelid neoplasms: a 10-year multicentre experience in southern coastal China

ObjectiveThis study aims to delineate the key characteristics of eyelid neoplasms in central and southern coastal China and to explore potential factors affecting tumour development. MethodsThis was a retrospective, multicentre observational study. In total, 1302 cases of eyelid neoplasms diagnosed in 2 tertiary hospitals were reviewed from January 2013 to May 2023. Histogenesis, pathologic diagnosis, and potential risk factors were investigated, and the findings were compared with data from various regions and countries. Age- and sex-specific incidence rates, time trends, distributions across age groups, and the relationship with the Sociodemographic Index, latitude, and altitude were calculated. ResultsThere were 1162 benign (89.2%) and 140 malignant (10.8%) cases, representing 63 pathologic types. The median age of benign cases (50 years) was significantly lower than that of malignant cases (72 years) (P < 0.05). The most common benign and malignant lesions were intradermal nevus (28.83%) and basal cell carcinoma (BCC) (74.29%). A relatively younger median age (68 years) for sebaceous gland carcinoma (SGC) was observed, with a male preponderance (sex ratio 2:1). Analyses of the proportions of BCC, SGC, and squamous cell carcinoma in eyelid malignancies revealed significant regression equations (P < 0.05). ConclusionsMost eyelid neoplasms are of epithelial and melanocytic origin, with benign tumours being predominant. The regions with greater Sociodemographic Index exhibit a greater incidence of BCC and a lower incidence of squamous cell carcinoma and SGC. BCC appears to have a greater incidence in regions located at higher latitudes.

EGR3 Inhibits Tumor Progression by Inducing Schwann Cell-Like Differentiation.

The mechanism and function of the expression of Schwann characteristics by nevus cells in the mature zone of the dermis are unknown. Early growth response 3 (EGR3) induces Schwann cell-like differentiation of melanoma cells by simulating the process of nevus maturation, which leads to a strong phenotypic transformation of the cells, including the formation of long protrusions and a decrease in cell motility, proliferation, and melanin production. Meanwhile, EGR3 regulates the levels of myelin protein zero (MPZ) and collagen type I alpha 1 chain (COL1A1) through SRY-box transcription factor 10 (SOX10)-dependent and independent mechanisms, by binding to non-strictly conserved motifs, respectively. Schwann cell-like differentiation demonstrates significant benefits in both in vivo and clinical studies. Finally, a CD86-P2A-EGR3 recombinant mRNA vaccine is developed which leads to tumor control through forced cell differentiation and enhanced immune infiltration. Together, these data support further development of the recombinant mRNA as a treatment for cancer.

Cutaneous melanocytic tumor with CRTC1::TRIM11 fusion: a case report

BackgroundCutaneous Melanocytic Tumor with CRTC1::TRIM11 Fusion (CMTCT) represents a novel and rare entity in the realm of dermatological oncology, characterized by distinct melanocytic differentiation. This particular tumor type has yet to be officially recognized by the World Health Organization (WHO). CMTCT is generally perceived as a tumor with a relatively indolent nature; however, it is not devoid of metastatic potential. Therefore, ensuring complete surgical excision of the tumor, coupled with rigorous long-term follow-up, is paramount for patient management. In this context, we report the case of an 18-year-old female patient who presented with a dull red nodule on her left leg. Initial surgical intervention led to a pathological diagnosis of CMTCT, but it was determined that the tumor had not been fully excised. Consequently, a second surgical procedure was undertaken to achieve complete removal of the tumor. During a follow-up period of six months post-surgery, the patient showed no signs of local recurrence or metastasis, indicating a successful outcome.Case presentationAn 18-year-old female patient noticed a dull red nodule on her left leg three years ago, which exhibited slow growth over time. She underwent a subcutaneous tumor resection. Histological examination under high-power magnification revealed that the neoplasm consisted of epithelioid cells arranged in nests, fascicles, bundles, or sheets. The tumor cells had round or ovoid nuclei with prominent nucleoli and visible mitotic figures. Notably, areas resembling nevus cell clusters were observed. Immunohistochemical analysis confirmed melanocytic differentiation. Next-generation sequencing (NGS) identified a CRTC1::TRIM11 fusion, and fluorescence in situ hybridization (FISH) for CRTC1 confirmed rearrangement. Consequently, a diagnosis of cutaneous melanocytic tumor with CRTC1::TRIM11 fusion was established.ConclusionsCMTCT is a rare tumor characterized by melanocytic differentiation. In this case, the tumor predominantly comprised epithelioid cells with localized nevus cell clusters. The expression of melanocyte markers could easily lead to a misdiagnosis as cutaneous melanoma. However, several distinguishing features were noted: the tumor was not connected to the epidermis, exhibited low cellular heterogeneity and proliferation index, and showed minimal cellular atypia. Additionally, tests for EWSR1 rearrangement (FISH) and BRAF V600E mutation (PCR-ARMS) were negative.This case underscores the importance of a comprehensive diagnostic approach when clinical, microscopic, immunohistochemical, and molecular findings do not align. The presence of nevus cell clusters morphology in the tumor cells enhances our understanding of this disease’s histological spectrum and aids in avoiding misdiagnosis or missed diagnosis.

Paris polyphylla saponins II inhibits invasive, migration and epithelial-mesenchymal transition of melanoma cells through activation of autophagy

Malignant melanoma is a kind of malignant tumor derived from normal epidermal melanocytes or original nevus cells. It has a high degree of malignancy, rapid progress, dangerous condition, and poor prognosis. In recent years, the innovation of traditional Chinese medicine has broadened the scope and effect of tumor treatment. It is a hotspot and breakthrough to find new anti-tumor invasion and migration drugs from natural plants or traditional Chinese medicine. This study explored the role of PPII in promoting autophagy to inhibit EMT of melanoma cells, the role of the PI3K/Akt signaling pathway in the invasion and migration of melanoma cells induced by PPII. We found that PPII effectively inhibited the proliferation, invasion and migration of melanoma B16 and B16F10 in vitro, and induced autophagy. We also established the xenograft tumor and metastatic tumor model of C57BL/6 mice with B16F10 cells. Results showed that PPII effectively inhibited the growth of transplanted tumors, induced autophagy and inhibited the expression level of EMT related protein; Metastasis experiment showed that PPII inhibited the invasion and migration of B16F10, the effect of inhibiting lung metastasis is the most significant. Further mechanism studies showed that the inhibition of PPII on melanoma invasion and migration is related to its induction of autophagy and then inhibition of EMT.

Histopathological characteristics analysis of giant melanocytic naevi in children.

The major diagnostic criterion for the giant congenital melanocytic nevus (GCMN) is a size larger than 20 cm in diameter. However, the histopathological origin, pathogenesis, and GCMN progression are not yet completely clear. Unlike other medium or small superficial lesions, histomorphological evaluation is significant for GCMN pathological classification, malignant transformation assessment, and early detection of prognosis. This study aimed to investigate the pathological features of GCMN, including its satellite lesions. Twenty-three giant naevi and seventeen "satellite lesions" were collected from children aged 1 to 10 in Shanghai Ninth People's Hospital from 2018 to 2020. A histological study was conducted to evaluate their histological appearance. All the data observed and recorded data were statistically analyzed. In 23 cases of GCMN primary nevus, nevus cells were mainly distributed in the dermal region, with melanocyte proliferation and the presence of nevus nests at the dermal-epidermal junction. However, in satellite nevus, a junctional growth pattern was noted. Additionally, other histopathologic features, including epidermal contour, cell morphology, and architecture disorder also showed significant differences between primary nevus and satellite nevus. We demonstrated that the congenital pattern of the main nevus is more obvious than one of the satellite nevus, suggesting that the satellite nevus and the main nevus may occur slightly later than the main nevus. "Satellite nevus" happens as a result of a separate genetic event.

Morphological characterization of nevi on the caruncle conjunctiva under in vivo confocal microscopy.

This study aimed to investigate the microscopic structure and characteristics of nevi on the conjunctiva of the lacrimal caruncle by in vivo confocal microscopy. In total, four patients with nevi growing on the lacrimal caruncle conjunctiva were recruited. The morphological characteristics of the nevi were evaluated by in vivo confocal microscopy before excision surgery; the results were compared with histopathological analyses of the surgical specimens. The nevi of the four patients were all located at the conjunctiva of the lacrimal caruncle, with a slightly nodular surface, mixed black and brown color, and clear boundary. The nevi were round and highly protruded on the surface of the lacrimal caruncle, with an average diameter of 4.5 ± 1.29 mm. Under in vivo confocal microscopy, the pigmented nevus cells on the conjunctiva of the lacrimal caruncle were observed to be clustered in nests with irregular boundaries. The cells were round or irregular, with clear cell boundaries, hyper-reflective at the periphery, with low reflectivity in the center. Vascular crawling was observed in some regions. Histopathological analysis showed that nevus cells were roughly equal in size and distributed in a nodular pattern. Melanin granules were observed in the cytoplasm. No atypia or mitotic figures of the cells were found. This study revealed that the microstructure of nevi growing on the conjunctiva of the lacrimal caruncle can be identified by in vivo confocal microscopy.

The association of BRAF V600E gene mutation with proliferative activity and histopathological characteristics of congenital melanocytic nevi in children

BackgroundA lot of congenital melanocytic nevi (CMN) carry the somatic mutation in the oncogene BRAF V600E. But the detailed histopathologic characteristics and the proliferative activity of CMN with BRAF V600E gene mutation have not been systematically documented. ObjectiveTo identify the proliferative activity and histopathological features correlating them with BRAF V600E gene mutation status in CMN. MethodsCMN were retrospectively identified from the laboratory reporting system. Mutations were determined by Sanger sequencing. The CMN were divided into a mutant group and control group according to whether there was BRAF gene mutation and were strictly matched according to gender, age, nevus size, and location. Histopathological analysis, analysis of Ki67 expression by immunohistochemistry and laser confocal fluorescence microscopy were performed. ResultsThe differences in Ki67 index, the depth of nevus cell involvement and the number of nevus cell nests between the mutant group and the control group was statistically significant, with p-values of 0.041, 0.002 and 0.007, respectively. Compared with BRAF V600E negative nevi, BRAF V600E positive nevi often exhibited predominantly nested intraepidermal melanocytes, and larger junctional nests, but the difference in this data sets were not statistically significant. The number of nests (p = 0.001) was positively correlated with the proportion of Ki67 positive cells. Study limitationsA small sample of patients were included and there was no follow-up. ConclusionsBRAF V600E gene mutations were associated with high proliferative activity and distinct histopathological features in congenital melanocytic nevi.

Comparing Follicular Extension Between Low-Grade and High-Grade Dysplastic Nevi.

Dysplastic nevi are an important subset of melanocytic nevi with atypical clinical, histopathologic, as well as genomic features compared with common acquired nevi. Dysplastic nevi are characterized histologically by both cytologic atypia and architectural disorder. The established criteria for cytologic atypia used to distinguish between low-grade and high-grade dysplastic nevi are often subjective, although there is a dearth of more objective, reproducible features of architectural disorder (eg, pagetoid scatter) that have been validated to differentiate between low-grade and high-grade dysplastic nevi. In this study, we sought to determine whether the presence and degree of follicular extension differ between low-grade and high-grade dysplastic nevi. We retrospectively examined the histopathologic features of 90 dysplastic nevi: 60 cases of low-grade dysplastic nevi (average age of 47.2 ± 18.1 years; 62.7% female) and 30 cases of high-grade dysplastic nevi (average age of 47.4 ± 19.8 years; 60.0% female). After examination, 50% of the cases of dysplastic nevi (n = 45) had hair follicles within the lesion, for which the presence and degree of follicular extension was then determined. Low-grade and high-grade dysplastic nevi do not differ significantly regarding the presence of follicular extension, average depth of follicular extension, and confluence of nevus cells along the follicular epithelium. Both low-grade and high-grade dysplastic nevi in our study demonstrated follicular extension that was superficial, that is, above the level of isthmus of hair follicles (insertion of sebaceous gland into hair follicle). Future studies are warranted to confirm these preliminary findings.

The Gingival Mole – Rare Case Report

Pigmented Nevi are benign tumors of the skin and mucosa characterized by the presence of melanin-producing, neuroectodermal derived nevus cells. Pigmented lesions usually pose an aesthetic concern to the patients and hence a clinical expertise is of utmost requirement for appropriate diagnosis and treatment for improved esthetics and patient satisfaction.

HISTOPATHOLOGICAL EVALUATION OF NEOPLASTIC LESIONS OF SKIN: A STUDY OF 71 CASES AT TERTIARY CARE CENTER

Introduction: The skin is the largest organ of the body. Skin tumors encompass a wide spectrum and belong to a diverse group of neoplasm rendering the classication difcult. The aim of our study was to study hist Aim: opathological types of skin tumors and distribution of skin tumors according to WHO classication The present study was a prospective &amp;ret Materials and methods: rospective study of skin tumours from January 2016 – April2019 at Department of Pathology, Government Medical College,Surat . The study included all histopathologically conrmed cases of skin tumors. Out of 71 skin tumours, 34 were benign,5 were borderline and 32were malignant. T Results: hus benign tumours were more common than malignant tumours with benign to malignant ratio of 2.05:1. Keratinocytic tumours were highest 25 cases (62%) followed by Melanocytic tumours 18 cases (18.18%). Benign tumours were common in younger age group whereas malignant tumors showed an ascending trend in age. Both benign and malignant tumours of skin were common in males than females Hi Conclusion: stopathological evaluation of skin biopsy is an important tool in diagnosis of skin neoplasms. Intradermal nevus and basal cell carcinoma was the most common benign and malignant neoplasm respectively. Malignant neoplasms were more common in older patients.

Differences in the immune microenvironment between improved and non-improved cases of vitiligo after halo nevus excision

BackgroundHalo nevus, also called Sutton’s nevus, is a nevus cell nevus surrounded by vitiligo thought to be caused by a T-cell mediated immune response to the nevus antigen. The immune microenvironment is mysterious, however, as vitiligo often does not improve even when the nevus cells are removed. ObjectivesTo analyze the clinical course and immune microenvironment of patients with halo nevus who had undergone nevus excision. MethodsWe collected 54 halo nevus patients and performed multivariate analysis and immunohistochemical analysis, including multiplexed immune cell phenotyping and spatial single-cell analyses using the PhenoCycler® assay. ResultsMultivariate analysis revealed that only the presence or absence of vitiligo vulgaris at the time of consultation was associated with improvement in the surrounding vitiligo following excision. Expression of programmed death-ligand 1 in nevus cells was significantly higher in non-improved cases compared with improved cases. The PhenoCycler® assay revealed that CD107a-positive and CD21-positive cells were more prevalent in improved cases than in non-improved cases. In the improved cases, active cell-cell interactions, centered on CD21-positive cells, were observed, whereas in the non-improved cases, cell-cell interactions were sparse. Instead, a dense infiltration of CD8-positive cells and CD3 and CD4-positive cells was observed in non-improved cases. ConclusionElucidation of the immune microenvironment of halo nevus is also relevant to melanoma-associated vitiligo and will contribute to our understanding of tumor immunity.

A Rare Case of Giant Congenital Melanocytic Nevi: A Case Report

Background: Giant congenital melanocytic nevi are often characterised as melanocytic lesions present at birth. It is thought that it affects 1 in 20,000 births. The lesion is significant because it may be associated with serious consequences, such as malignant melanoma, and may also result in neurological deficits, such as neurocutaneous melanocytosis. This study aimed to present the case of giant congenital melanocytic nevus as a rare case.&#x0D; Case presentation: This study reported a 14-year-old female reported with large blackish rough spots on the trunk that were neither itchy or painful since birth. The patient had no previous history of convulsions, headaches, or vomiting. Plaque hyperpigmentation, macula hyperpigmentation, and hypertrichosis were found on the trunk. Dermoscopy show reveals brown-black homogeneity. Histopathology examination reveals brown-pigmented nevus cells distributed diffusely, with some nevus cells surrounding adnexa skin.&#x0D; Conclusion: Regular examination is essential to monitor the possibility of neurocutaneous melanosis and malignant melanoma development.

Preparation of Cod Skin Collagen Peptides/Chitosan-Based Temperature-Sensitive Gel and Its Anti-Photoaging Effect in Skin.

Photoaging decreases quality of life and increases the risk of skin cancer, underscoring the urgent need to explore natural, high-efficacy, anti-skin photoaging (SP) active substances. In this study, a gel (CS/CSCPs/β-GP gel) was prepared using chitosan (CS) and sodium β-glycerophosphate (β-GP) through crosslinking with small molecular CSCPs as the carried drug. We evaluated its structural characteristics and properties. The effect of CS/CSCPs/β-GP gel on the degree of ultraviolet (UV)-induced skin aging of mice was investigated through comparative analysis of skin damage, the integrity of collagen tissues and elastic fibers, levels of reactive oxygen species (ROS) and key inflammatory factors (tumor necrosis factor [TNF]-α and interleukin [IL]-1β, IL-6, and IL-10), and tissue expression of matrix metalloproteinase-3 (MMP-3) after repeated UV irradiation in a nude mice SP model. The results showed that CS/CSCPs/β-GP gel was successfully prepared and had the desired characteristics. Compared with CSCPs alone, the CS/CSCPs/β-GP gel more evidently improved typical photoaging characteristics on mouse dorsal skin. It also increased the moisture content, causing the skin to become glossy and elastic. Pathological skin analysis revealed that this peptide-carrying gel can effectively inhibit epidermal thickening, reduce tissue inflammatory infiltration, suppress collagen fiber degradation, increase the collagen content, alleviate structural elastic fiber damage, and significantly inhibit abnormal MMP-3 expression. In addition, biochemical analysis showed that the CS/CSCPs/β-GP gel can effectively inhibit the elevated expressions of ROS and key proinflammatory factors (TNF-α, IL-1β, IL-6) in photoaging skin tissues and promote expression of the anti-inflammatory factor IL-10. SP can cause many clinical skin diseases, such as solar freckle-like nevus, solar keratosis, cutaneous melanoma, and squamous cell carcinoma. CSCPs are a high-efficacy anti-SP natural active substance and CS/CSCPs/β-GP gel can synergistically enhance the CSCPs' anti-SP effect. The mechanism is likely related to the inhibited activation of ROS/nuclear transcription factor-κB signaling and the expression of downstream inflammatory factors.

Expression of pH-Sensitive TRPC4 in Common Skin Tumors.

TRPCs (transient receptor potential classical or cation channels) play a crucial role in tumor biology, especially in the Ca2+ homeostasis in cancer cells. TRPC4 is a pH-sensitive member of this family of proteins. As solid tumors exhibit an inversed pH-gradient with lowered extracellular and increased intracellular pH, both contributing to tumor progression, TRPC4 might be a signaling molecule in the altered tumor microenvironment. This is the first study to investigate the expression profiles of TRPC4 in common skin cancers such as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), malignant melanoma (MM) and nevus cell nevi (NCN). We found that all SCCs, NCNs, and MMs show positive TRPC4-expression, while BCCs do only in about half of the analyzed samples. These data render TRPC4 an immunohistochemical marker to distinguish SCC and BCC, and this also gives rise to future studies investigating the role of TRPC4 in tumor progression, and especially metastasis as BCCs very rarely spread and are mostly negative for TRPC4.

A curious swelling of the lingual gingiva: case report

Introduction: Melanocytic nevi are benign tumors composed of nevus cell, thought to be derived from the neural crest. While they are unusual in the oral mucosa, they contrastingly represent the most diagnosed pigmented lesion on the skin. Observations: A 68-year-old woman presented with an asymptomatic ”epulis-like”, pale pink swelling of the lingual gingiva and slowly growing in the last 6 months. Excisional biospy was performed with a hypothesis of fibroma but the histopathologic examination revealed surprisingly an achromic intramucosal nevus. Conclusion: The unusual appearance in these cases suggests that oral melanocytic nevi should be included as a rare possibility in the differential diagnosis of swellings in the gingiva, regardless of their clinical pigmentation.

Ocular Melanocytoma

Abstract Melanocytoma, also known as magnocellular nevus, most commonly occurs on the optic disk, sometimes involving the adjacent retina or choroid. It may be confused with malignant melanoma both clinically and histopathologically. Histopathologically, melanocytoma is composed of deeply pigmented, round to oval nevus cells without malignant features. Typically, melanocytoma is benign1 and shows a stationary course, although minor enlargement occurs in 10%–15% of cases. In rare cases, severe visual loss can result from tumor necrosis, compressive optic neuropathy, or malignant transformation, which occurs in 1%–2% of cases. Therefore, it is generally a benign lesion requiring minimal intervention but warrants lifetime follow-up.

An Improved Transfer Learning Approach for Classification of Types of Cancer

Melanoma mortality rate is very high and is one kind of skin cancer. So, it is essential to identify skin cancer at an initial phase hence we can minimize the mortality rate, but sometimes recognition of the skin lesion type is very difficult due to its similarity leads to wrong treatment. Hence it is required to classify the skin lesion accurately at an initial phase for medicating a patient accurately and to save their lives. Here we proposed a framework for a very precise skin lesions classification. This uses transfer learning along with a pre-trained model and MobileNet. By using our proposed system, we can categorize the different skin lesion types accurately. Lesions are divided into eight types including melanoma, benign keratosis, basal cell carcinoma, actinic keratosis, melanocytic nevus, vascular lesion, dermatofibroma, and squamous cell carcinoma. The dataset used is ISIC 2019 challenge dataset to perform experiment on types of skin lesions. If the input image is not classified in any one of the eight types, then that image is classified as an unknown image. Hence, according to experiment our proposed system able to find the lesion type very accurately and will help to dermatologist to do accurate treatment.

Role of dermoscopy in diagnosing and differentiating seborrheic keratoses

Background Seborrheic keratosis is one of the most common benign epidermal tumors seen in elderly individuals. It has slow growth and presents with a varied degree of pigmentation in skin color closely resembling many other pigmented dermatoses. Dermoscopy, a noninvasive technique, could increase the accuracy of diagnosis and can differentiate it from various closest mimickers and malignancies. Aim This study aims to describe the various dermoscopic features of seborrheic keratosis in a series of cases. Patients and methods A hospital-based, descriptive study was conducted over 12 months from January 2018 to December 2018 in the Department of Dermatology, a tertiary-care center. A total of 100 patients were selected and evaluated in a prestructured proforma concerning age, sex, site of lesion, number and duration, and associated comorbidities. The lesion is observed on dermoscopy, and the dermoscopic patterns were then documented and analyzed. Result Among a total of 100 (32%) cases, the most common age group was between 41 and 50 years with females (52%) outnumbering males (48%). The most common site was the face (38%), and the common morphology was plaque (60%). Sign of Leser-Trélat was observed in five patients of which three were associated with malignancy that includes two lymphomas and one breast carcinoma. The color on dermoscopy was predominant dark brown (43%) and brownish-black (32%). The common element was clod (39%) and combined clod and dots (18%). More than three colors and more than two elements in a single lesion were observed in 15 and 11% of cases, respectively. The dermoscopic clues of seborrheic keratosis with highest to lowest prevalence were cerebriform pattern (76%), sharp demarcation (64%), comedone-like opening (56%), milia-like cyst (54%), mica-like scales (52%), moth-eaten border (46%), jelly sign (40%), fingerprint-like pattern (40%), fat fingers (36%), peripheral globules/network (34%), coral-like structure (26%), papillary structures (26%), irregular globules (12%), irregular opaque brown pigmentation (12%), and yellow-orange areas (3%). The flat seborrheic keratosis predominantly showed an irregular network-like structure, fat fingers, milia-like cyst, and accentuation of two adjacent perifollicular pigmentations forming a double ring-like structure (16%). The raised lesions predominantly showed fissures/ridges (cerebriform pattern), exophytic papillary structures, opaque pigmentation, and a mica-like pattern. Ten lesions were misinterpreted as seborrheic keratosis clinically and on dermoscopy were verruca vulgaris (2/10, 20%), melanocytic nevus (3/10, 30%), and basal cell carcinoma (5/10, 50%), which were confirmed on histopathology. Conclusion The study emphasizes the use of dermoscopy in seborrheic keratosis to improve the clinical accuracy of diagnosis and also to differentiate from its common mimickers.

ORAL PIGMENTED LESION: A CASE REPORT

A 67-year-old female patient presented in intraoral examination a darkened spot in the maxilla region above the central incisors, near the bottom of the vestibule, which extended to the hard palate. She reported that, 52 years ago, she had suffered a trauma that resulted in fracture of tooth 21, and a paraendodontic surgery was performed with apicectomy and insertion of metallic material, but there was no success, and the tooth was extracted. Diagnostic hypotheses considered were as follows: extrinsic pigmentation, melanoma, and melanosis by nevus cells. Periapical radiography was performed, but no metallic fragment was found. Then, an incisional biopsy was performed with a final diagnosis of amalgam tattoo. There was no recurrence in 6 months follow-up. It is concluded that, regardless of the extension, location, and nonidentification of a radiopaque fragment on radiographs, the previous clinical history is important for appropriate diagnosis and management.