Untapped saga of paediatric nevo-blaschkoid seborrheic keratosis.

Seborrheic keratosis (SK) has long been known to be an acquired benign tumour of adulthood. Nevo-blaschkoid pattern of SK presenting during infancy is rare and puts a clinician in a quandary regarding final diagnosis. This hypothesis of paediatric SK being a subtype of epidermal nevus (EN) has muddled the understanding of both disorders. There are histopathological pointers that differentiate seborrheic keratosis from SK-like histology of EN. Here, we present a child with blaschkoid SK with onset during infancy. Dermoscopic evaluation showed comedo-like openings suggestive of SK. The benefits of performing shave biopsy were twofold. Diagnostic confirmation of it being SK and not SK-type of EN and therapeutic option of their simultaneous removal ensured prompt management.

Deep learning-assisted multispectral imaging for early screening of skin diseases.

INTRODUCTION: Melanocytic nevi (MN), warts, seborrheic keratoses (SK), and psoriasis are four common types of skin surface lesions that typically require dermatoscopic examination for definitive diagnosis in clinical dermatology settings. This process is labor-intensive and resource-consuming. Traditional methods for diagnosing skin lesions rely heavily on the subjective judgment of dermatologists, leading to issues in diagnostic accuracy and prolonged detection times. OBJECTIVES: This study aims to introduce a multispectral imaging (MSI)-based method for the early screening and detection of skin surface lesions. By capturing image data at multiple wavelengths, MSI can detect subtle spectral variations in tissues, significantly enhancing the differentiation of various skin conditions. METHODS: The proposed method utilizes a pixel-level mosaic imaging spectrometer to capture multispectral images of lesions, followed by reflectance calibration and standardization. Regions of interest were manually extracted, and the spectral data were subsequently exported for analysis. An improved one-dimensional convolutional neural network is then employed to train and classify the data. RESULTS: The new method achieves an accuracy of 96.82 % on the test set, demonstrating its efficacy. CONCLUSION: This multispectral imaging approach provides a non-contact and non-invasive method for early screening, effectively addressing the subjective identification of lesions by dermatologists and the prolonged detection times associated with conventional methods. It offers enhanced diagnostic accuracy for a variety of skin lesions, suggesting new avenues for dermatological diagnostics.

Bowen disease with sebaceous differentiation arising from clonal seborrheic keratosis.

We present a rare case of clonal seborrheic keratosis (SK) with focal Bowen disease (BD) (squamous cell carcinoma in situ) accompanied by sebaceous differentiation. An 89-year-old woman presented with a pale reddish-brown plaque on the left buttock. Histopathological examination of the excisional specimen revealed hyperkeratosis, acanthosis, and intraepidermal epithelioma. In some areas of the tumor, we observed proliferation of basaloid keratinocytes within the intraepidermal nests and pseudohorn cysts. This area was diagnosed as clonal SK. However, in other areas, the tumor cells within the intraepidermal nests showed nuclear pleomorphism, abnormal mitoses, dyskeratotic cells, and clumping cells, consistent with BD with a nested/clonal pattern (clonal BD). The SK and BD areas were contiguous with the transitional zone. Some nests within the BD area contained vacuolated cells with bubbly cytoplasm and scalloped nuclei, suggestive of sebaceous differentiation. Therefore, we made the diagnosis of clonal BD with sebaceous differentiation arising from clonal SK. All areas contained intraepidermal nests, which revealed that the lesions were not the result of accidental collision, but that the neoplastic cells in the intraepidermal nests of the SK transformed into BD and underwent sebaceous differentiation.

Tumor of follicular infundibulum - reappraisal in a series of 28 patients with critical review of the literature.

BACKGROUND AND OBJECTIVES: Tumor of follicular infundibulum (TFI) has been described as a neoplasm - isolated and multiple - and in association with other lesions. Its histopathologic definition is controversial. PATIENTS AND METHODS: We present a histopathologically analyzed series of 28 patients with TFI features. This has been supplemented by a search in MEDLINE on the literature on this subject. The corresponding figures given in these articles have been discussed and analyzed. RESULTS: Patients comprised 16 women and twelve men. TFI features were seen in five patients with nevus sebaceous, two trichofolliculomas, one dilated pore Winer, eight viral warts, one dermatofibroma, six seborrheic keratoses, three actinic keratoses, one invasive squamous cell carcinoma, and one basal cell carcinoma in association with a squamous cell carcinoma/actinic keratosis. After study of the literature especially of solitary cases of TFI, we interpret such cases mostly as variants of seborrheic keratoses with variable degree of infundibular, isthmic and/or sebaceous differentiation with or without regression. CONCLUSIONS: We regard TFI as an epithelial growth pattern which may occur in hamartomatous, inflammatory, infectious, reactive, or neoplastic conditions, in most solitary forms likely best classified within the histopathological spectrum of seborrheic keratoses.

Evaluation and management of benign tumors of the eye and eyelid.

Benign tumors of the eye and eyelid are common in children and adults, and they rarely undergo malignant transformation. Their workup and management have evolved over the years with increasing advancements in surgical and laser therapies. This contribution focuses on describing the following benign eye and eyelid tumors and their diagnostic and treatment approaches: congenital and acquired melanocytic nevi; nevus of Ota (Hori nevus); conjunctival papilloma; seborrheic keratosis; epidermoid cyst; dermoid cyst; milium; xanthelasma; hemangioma (cherry angioma and pyogenic granuloma); neurofibroma; neurilemmoma (schwannoma); and fibroepithelial polyp. Surgical removal is the primary treatment approach for many of these benign tumors. With advancements in laser technologies, there are now several laser types that can be used in the treatment of these benign eye and eyelid tumors. Other treatment modalities include cryosurgery, electrosurgery, and topical or intralesional medications. We hope this review will provide a reference to dermatologists and ophthalmologists in their approach to evaluation and management of benign eye and eyelid tumors.

Melanoma clinicopathological groups characterized and compared with dermoscopy and reflectance confocal microscopy.

BACKGROUND: Dermoscopic and reflectance confocal microscopy (RCM) correlations between morphologic groups of melanoma have not yet been described. OBJECTIVE: Describe and compare dermoscopic and RCM features of cutaneous melanomas with histopathological confirmation. METHODS: Single center, retrospective analysis of consecutive melanomas evaluated with RCM (2015-2019). Lesions were clinically classified as typical, nevus-like, amelanotic/nonmelanoma skin cancer (NMSC)-like, seborrheic keratosis (SK)-like and lentigo/lentigo maligna (LM)-like. Presence or absence of common facial and nonfacial melanoma dermoscopic and RCM patterns were recorded. Clusters were compared with typical lesions by multivariate logistic regression. RESULTS: Among 583 melanoma lesions, significant differences between clusters were evident (compared to typical lesions). Observation of dermoscopic features (>50% of lesions) in amelanotic/NMSC-like lesions consistently displayed 3 patterns (atypical network, atypical vascular pattern + regression structures), and nevus-like and SK-like lesions and lentigo/LM-like lesions consistently displayed 2 patterns (atypical network + regression structures, and nonevident follicles + heavy pigmentation intensity). Differences were less evident with RCM, as almost all lesions were consistent with melanoma diagnosis. LIMITATIONS: Small SK-like lesions sample, single RCM analyses (no reproduction of outcome). CONCLUSION: RCM has the potential to augment our ability to consistently and accurately diagnose melanoma independently of clinical and dermoscopic features.

The Leser-Trélat Sign in a Patient with Gastric Adenocarcinoma.

Dear Editor, The Leser-Trélat sign is a rare paraneoplastic cutaneous marker of internal malignancy characterized by sudden eruption of multiple seborrheic keratoses (SK). It is mostly associated with gastrointestinal adenocarcinomas (gastric, colon, rectal), and less frequently with breast cancer and lymphoproliferative disorders/lymphoma (1). It can be also associated with lung, kidney, liver, and pancreas malignancy (1). Pruritus occurs in half of the patients. Lesions rarely require any treatment, as they mostly tend to resolve once management of the underlying malignancy has started (2). A 32-year-old female patient with family history of colorectal cancer presented with an acute eruption of SK. She reported that the first symptoms were the loss of appetite and intense pruritus. The brown papules appeared over a period of 2-3 months, first on her back, then on the abdomen, thorax, neck, and lasty on the extremities (Figures 1a and b.). Physical examination showed numerous brown hyperkeratotic papules and plaques on the trunk, neck, and extremities. The patient complained of night sweating, epigastric pain, and heartburn. Over the last three months, she had lost over 15 kg. The patient had experienced an episode of acute gastritis 10 years ago and had been treated for Helicobacter pylori infection 4 years ago. Laboratory results showed elevated sedimentation rate and decreased levels of hemoglobin, erythrocytes, and hematocrit. CA-19-9 and CEA levels were elevated. Gastroscopy with multiple biopsies confirmed gastric adenocarcinoma. An abdominal CT scan revealed enlarged retroperitoneal lymph nodes. SK withdrew after total gastrectomy and commencement of chemotherapy. The Leser-Thrélat sign was named after two surgeons, Edmund Leser and Ulysse Trélat, who described the eruption of cutaneous lesions in patients with cancer (3). However, the correlation between multiple SK and internal malignancy was described by Hollander in 1900 (4). Acute eruption of SK has also been reported in some other cases, such as benign tumors, pregnancy, human immunodeficiency virus infections, use of adalimumab, and others, which indicates that the Leser-Trélat sign is not highly specific (5). It is also somewhat controversial whether a sudden appearance of SK can be considered a marker for internal malignancy, since both SK and malignancies occur more frequently in the elderly population, thus allowing for a higher likelihood of coincidence (6). However, the patient in this case was young and therefore less likely to suddenly develop such a large number of SK, which are more commonly seen after the age of 50 (7). Although the pathogenesis of Leser-Thrélat sign is not fully understood, there are data suggesting an association with tumor-secreting growth factors including epidermal growth factor and transforming growth factor-alpha, both of which can stimulate the epidermal growth factor receptor (8). Sudden appearance of eruptive SK is uncommon in young patients. This specific sign highlights the importance of considering internal malignancy in the differential diagnosis of patients presenting with eruptive SK.

Deep convolutional neural network with fusion strategy for skin cancer recognition: model development and validation.

We aimed to develop an accurate and efficient skin cancer classification system using deep-learning technology with a relatively small dataset of clinical images. We proposed a novel skin cancer classification method, SkinFLNet, which utilizes model fusion and lifelong learning technologies. The SkinFLNet's deep convolutional neural networks were trained using a dataset of 1215 clinical images of skin tumors diagnosed at Taichung and Taipei Veterans General Hospital between 2015 and 2020. The dataset comprised five categories: benign nevus, seborrheic keratosis, basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. The SkinFLNet's performance was evaluated using 463 clinical images between January and December 2021. SkinFLNet achieved an overall classification accuracy of 85%, precision of 85%, recall of 82%, F-score of 82%, sensitivity of 82%, and specificity of 93%, outperforming other deep convolutional neural network models. We also compared SkinFLNet's performance with that of three board-certified dermatologists, and the average overall performance of SkinFLNet was comparable to, or even better than, the dermatologists. Our study presents an efficient skin cancer classification system utilizing model fusion and lifelong learning technologies that can be trained on a relatively small dataset. This system can potentially improve skin cancer screening accuracy in clinical practice.

Malignant Melanoacanthoma.

ABSTRACT: Melanoacanthomas are benign variations of seborrheic keratosis that have been known to mimic other common benign and malignant skin lesions. Therefore, the diagnosis typically requires biopsy and careful histologic examination. Here, we present the case of a 25-year-old woman initially diagnosed clinically with an epidermal inclusion cyst, but, on biopsy and further evaluation, was found to have histological features of an atypical or malignant melanoacanthoma. Contrary to typical cases of melanoacanthoma, histologic evaluation revealed atypical findings consistent with malignancy, such as tumor necrosis, marked cytologic atypia and pleomorphism, and numerous mitoses, including atypical forms, features consistent with malignancy (ie, similar to a squamous cell carcinoma in these areas). This report highlights the importance of histological evaluation in diagnosis and treatment of skin lesions because atypical presentations often occur and can delay correct diagnosis and appropriate treatment.

Umbilical seborrheic keratosis-like lesion developing after diode laser hair removal in an 18-year-old patient.

OBJECTIVE: to report a possibly novel complication of laser hair removal. CASE REPORT: a white-skinned 18-year-old patient discovered an umbilical, brown, and raised lesion while shaving before his second diode laser hair removal session. He sought consultation before his fourth laser session since the lesion further thickened and darkened. Dermoscopy showed no pigmented network, but a few comedo-like openings within an erythematous-light brown scaly and fissured papule, "moth-eaten" borders, and a central crust due to manipulation, suggesting the diagnosis of seborrheic keratosis. We noted that the laser fluence was increased on the umbilical region where hair seemed resistant to treatment. The patient denied a recent history of local sun tanning, sunburns, inflammation, drainage, or manipulation. The lesion cleared, with no short-term relapse, after one session of cryotherapy. CONCLUSION: the development of a seborrheic keratosis-like lesion on a densely haired non-sun-exposed umbilicus of a young patient, following pre-laser shaving and high-fluence hair removal diode laser sessions, could have implicated triggering irritation and/or keratinocyte stimulation by red light-engendered reactive oxygen species (ROS) in the skin with silent epidermal mosaicism.

Seborrheic keratosis.

Seborrheic keratosis (SK) is the most common benign epidermal tumor in clinical dermatological practice. This review summarizes current knowledge about the clinical and histological appearance, epidemiology, pathogenesis, and treatment of SK. There are different subtypes of SK based on clinical presentation and histologic findings. Several factors, including age, genetic predisposition, and possibly also exposure to ultraviolet radiation, are thought to contribute to the development of SK. The lesions can occur on all areas of the body except for the palms and soles, but the most common sites are the face and upper trunk. The diagnosis is usually made clinically, and in some cases by dermatoscopy or histology. Many patients prefer to have the lesions removed for cosmetic reasons although there is no medical indication. Treatment options include surgical therapy, laser therapy, electrocautery, cryotherapy, and topical drug therapy, which is currently in development. Treatment should be individualized depending on the clinical picture and patient preference.

Pigmented Inflamed Seborrheic Keratosis of the Bulbar Conjunctiva.

A 57-year-old Black man presented with the recent onset of a pigmented temporal epibulbar lesion. As pigmentation of conjunctival epithelial lesions is correlated with complexion pigmentation, the lesion was presumed to represent a pigmented ocular surface squamous neoplasia (OSSN). Excisional biopsy, however, revealed a pigmented conjunctival seborrheic keratosis, a rare occurrence. The lesion lacked cytologic atypia. Intralesional processes of dendritic melanocytes were demonstrated by hematoxylin-eosin and Melan-A stains. Melanophages also contributed to clinical pigmentation. Subepithelial lymphocytic infiltration, elevated Ki67 proliferative rate, prominent mitotic activity, and subtle spongiosis afforded evidence of inflammation rather than malignancy in a lesion devoid of cytologic atypia.

Update of pathophysiology and treatment options of seborrheic keratosis.

Seborrheic keratosis (SK) is a common, benign tumor that can occur on everybody site and can be conservatively managed. Cosmetic concerns, especially when a lesion involves the facial area, are the most common reason for excision. SK shows male gender preponderance and increasing age is an independent association with the condition. Even though more prevalent in the elderly, it has also been reported in younger age groups like adolescents and young adults. Precise pathogenesis is still obscure, but ultra-violet exposure represents a predisposing factor to SK by altering the biochemical concentration and expression of factors like Glutamine deaminases, endothelin, and stem cell factor. Moreover, the accumulation of amyloid-associated protein has also been postulated. Involvement of genitalia has been associated with human papillomavirus infection. Recently, Merkel cell polyomavirus nucleic acid was also detected in SK. Several oncogenic mutations involving FGFR-3 and FOXN1 have been identified. SKs are usually classified clinically and histologically. Dermatoscopy is a noninvasive alternative diagnostic technique widely used in differentiating SK from other benign and malignant tumors. In terms of treatment, topical agents, shave dissection, cryosurgery, electrodesiccation, laser application and curettage under local anesthesia are safe methods for eradication of SKs, mostly for cosmetic purposes. Though generally safe, the latter techniques may occasionally cause post-procedure depigmentation, scarring, and recurrence. Nanosecond-pulsed electric field technology is a promising new technique with fewer side-effects.