Cutaneous larva migrans in the northeastern US

Cutaneous larva migrans (CLM) is a dermo-epidermal parasitic infection with a disproportionate incidence in developing countries, particularly in, and near tropical areas. It is characterized by erythematous, twisting, and linear plaques that can migrate to adjacent skin. Herein, we present an otherwise healthy 45-year-old woman who acquired a pruritic, erythematous, and serpiginous rash localized to her right medial ankle during a trip to New England. Oral ivermectin, the preferred first-line treatment for cutaneous larva migrans, was administered in combination with triamcinolone. This was followed by removal of the papular area via punch biopsy; treatment was successful with a one-week recovery. Although cutaneous larva migrans has traditionally been considered a tropical disease, clinicians should be cognizant of its expanding geographic spread.

Incidence Trends of Primary Cutaneous T-Cell Lymphoma in the US From 2000 to 2018: A SEER Population Data Analysis

Using SEER database data, this cohort study analyzed cutaneous T-cell lymphoma incidence by tumor subtype, sex, age, race and ethnicity, socioeconomic status, and geography.

Disparities in dermatology AI performance on a diverse, curated clinical image set

An estimated 3 billion people lack access to dermatological care globally. Artificial intelligence (AI) may aid in triaging skin diseases and identifying malignancies. However, most AI models have not been assessed on images of diverse skin tones or uncommon diseases. Thus, we created the Diverse Dermatology Images (DDI) dataset-the first publicly available, expertly curated, and pathologically confirmed image dataset with diverse skin tones. We show that state-of-the-art dermatology AI models exhibit substantial limitations on the DDI dataset, particularly on dark skin tones and uncommon diseases. We find that dermatologists, who often label AI datasets, also perform worse on images of dark skin tones and uncommon diseases. Fine-tuning AI models on the DDI images closes the performance gap between light and dark skin tones. These findings identify important weaknesses and biases in dermatology AI that should be addressed for reliable application to diverse patients and diseases.

In Vivo Reflectance Confocal Microscopy of Cutaneous Acute Graft-Versus-Host Disease: Concordance with Histopathology and Interobserver Reproducibility of a Glossary with Representative Images

BACKGROUND

The reliability to noninvasively identify features of inflammatory dermatoses by reflectance confocal microscopy (RCM) remains unknown. Lack of formal training among RCM readers can result in inconsistent assessments, limiting clinical utility. Specific consensus terminology with representative images is necessary to ensure consistent feature-level interpretation among RCM readers.

OBJECTIVES

(1) Develop a glossary with representative images of RCM features of cutaneous acute graft-versus-host disease (aGVHD) for consistent interpretation among observers, (2) assess the interobserver reproducibility among RCM readers using the glossary, and (3) determine the concordance between RCM and histopathology for aGVHD features.

METHODS

Through an iterative process of refinement and discussion among five international RCM experts, we developed a glossary with representative images of RCM features of aGVHD. From April to November 2018, patients suspected of aGVHD were imaged with RCM and subsequently biopsied. 17 lesions from 12 patients had clinically and pathologically confirmed cutaneous aGVHD. For each of these lesions, four dermatopathologists and four RCM readers independently evaluated the presence of aGVHD features in scanned histopathology slides and 1.5x1.5 mm RCM submosaics at 4 depths (blockstacks), respectively. RCM cases were adjudicated by a fifth RCM expert. Interobserver reproducibility was calculated by U statistic. Concordance between modalities was determined by fraction agreement.

RESULTS

We present a glossary with representative images of 18 aGVHD features by RCM. The average interobserver reproducibility among RCM readers (75%, confidence interval, CI: 71%-79%) did not differ significantly from dermatopathologists (80%, 76%-85%). The concordance between RCM and histopathology was 59%.

CONCLUSIONS

By using the glossary, the interobserver reproducibility among RCM readers was similar to the interobserver reproducibility among dermatopathologists. There was good concordance between RCM and histopathology to visualize aGVHD features. The implementation of RCM can now be advanced in a variety of inflammatory conditions with a validated glossary and representative image set.

Spitz nevus with EHBP1-ALK fusion and distinctive membranous localization of ALK

ALK rearrangements define a histopathologically distinctive but diverse subset of Spitz tumors characterized by fusiform to epithelioid melanocytes with frequent fascicular growth and ALK overexpression. Molecularly, these tumors are characterized by fusions between ALK and a variety of other genes, most commonly TPM3 and DCTN1. We describe an unusual case of a Spitz nevus occurring in a 13-year-old female that manifested ALK immunopositivity with cell membrane localization. The proliferation was polypoid and composed of elongated nests of epithelioid melanocytes with enlarged nuclei, prominent nucleoli, and abundant cytoplasm without significant atypia and lacking mitotic figures. The nevus exhibited strong and diffuse expression of p16. Targeted next-generation RNA sequencing revealed an in-frame EHBP1-ALK fusion, which has been reported only once in the literature. EHBP1 encodes an adaptor protein with plasma membrane targeting potential. Together, these findings suggest that the 5' ALK fusion partner in Spitz tumors may dictate the subcellular localization of the ALK chimeric oncoprotein. In summary, this case highlights a rare ALK fusion associated with a distinct immunohistochemical staining pattern and further expands the spectrum of ALK-rearranged melanocytic tumors. This article is protected by copyright. All rights reserved.

Immunohistochemical ALK Expression in Granular Cell Atypical Fibroxanthoma: A Diagnostic Pitfall for ALK-Rearranged Non-neural Granular Cell Tumor

ABSTRACT

Atypical fibroxanthoma (AFX) is a neoplasm that most commonly occurs on sun-damaged skin of the head and neck in elderly patients and that usually exhibits indolent clinical behavior with complete excision. The granular cell variant of AFX demonstrates overlapping histopathologic features with dermal non-neural granular cell tumor (NNGCT), which typically arises on the extremities of young to middle aged adults with rare reports of regional metastasis. A subset of NNGCT harbors ALK rearrangements and expresses ALK by immunohistochemistry. Here, we present 2 cases of granular cell AFX occurring on the scalp of males aged 73 and 87 with ALK expression by immunohistochemistry and no evidence of an ALK rearrangement on fluorescence in situ hybridization, representing a diagnostic pitfall for NNGCT.

Next-generation sequencing confirms T-cell clonality in a subset of pediatric pityriasis lichenoides

BACKGROUND

Pityriasis lichenoides (PL) is a papulosquamous disease that affects both adults and children. Previous studies have shown a subset of this entity to have clonal T-cell populations via PCR-based assays. In this study, we sought to implement next-generation sequencing (NGS) as a more sensitive and specific test to examine for T-cell clonality within the pediatric population.

METHODS

We identified 18 biopsy specimens from 12 pediatric patients with clinical and histopathologic findings compatible with PL. Patient demographics, clinical features, management, and histopathologic findings were reviewed. All specimens were analyzed for clonality with NGS of T-cell receptor beta (TRB) and gamma (TRG) genes.

RESULTS

Of the 12 patients, 9 (75%) had complete resolution of lesions at the time of data collection (mean follow-up 31 months). The remaining three patients significantly improved with methotrexate (with or without acitretin). Interestingly, 7 of 12 patients (58%) and 9 of 17 biopsy specimens (53%) showed evidence of T-cell clonality. Two patients showed matching TRB clones from different anatomic sites.

CONCLUSIONS

T-cell clonality is a common finding in PL, probably representing a "reactive clonality" rather than a true lymphoproliferative disorder. Clonality alone cannot be used as a means to distinguish PL from lymphomatoid papulosis or cutaneous lymphoma.

Appropriate use criteria for ancillary diagnostic testing in dermatopathology: New recommendations for 11 tests and 220 clinical scenarios from the American Society of Dermatopathology Appropriate Use Criteria Committee

BACKGROUND

Appropriate use criteria (AUC) provide patient-centered physician guidance in test selection. An initial set of AUC was reported by the American Society of Dermatopathology (ASDP) in 2018. AUC reflect evidence collected at single timepoints and may be affected by evolving evidence and experience. The objective of this study was to update and expand AUC for selected tests.

METHODS

RAND/UCLA (RAND Corporation [Santa Monica, CA]/University of California Los Angeles) methodology used includes the following: (a) literature review; (b) review of previously rated tests and previously employed clinical scenarios; (c) selection of previously rated tests for new ratings; (d) development of new clinical scenarios; (e) selection of additional tests; (f) three rating rounds with feedback and group discussion after rounds 1 and 2.

RESULTS

For 220 clinical scenarios comprising lymphoproliferative (light chain clonality), melanocytic (comparative genomic hybridization, fluorescence in situ hybridization, reverse transcription polymerase chain reaction, telomerase reverse transcriptase promoter), vascular disorders (MYC), and inflammatory dermatoses (periodic acid-Schiff, Gömöri methenamine silver), consensus by panel raters was reached in 172 of 220 (78%) scenarios, with 103 of 148 (70%) rated "usually appropriate" or "rarely appropriate" and 45 of 148 (30%), "appropriateness uncertain."

LIMITATIONS

The study design only measures appropriateness. Cost, availability, test comparison, and additional clinical considerations are not measured. The possibility that the findings of this study may be influenced by the inherent biases of the dermatopathologists involved in the study cannot be excluded.

CONCLUSIONS

AUC are reported for selected diagnostic tests in clinical scenarios that occur in dermatopathology practice. Adhering to AUC may reduce inappropriate test utilization and improve healthcare delivery.

TrueImage: A Machine Learning Algorithm to Improve the Quality of Telehealth Photos

Telehealth is an increasingly critical component of the health care ecosystem, especially due to the COVID-19 pandemic. Rapid adoption of telehealth has exposed limitations in the existing infrastructure. In this paper, we study and highlight photo quality as a major challenge in the telehealth workflow. We focus on teledermatology, where photo quality is particularly important; the framework proposed here can be generalized to other health domains. For telemedicine, dermatologists request that patients submit images of their lesions for assessment. However, these images are often of insufficient quality to make a clinical diagnosis since patients do not have experience taking clinical photos. A clinician has to manually triage poor quality images and request new images to be submitted, leading to wasted time for both the clinician and the patient. We propose an automated image assessment machine learning pipeline, TrueImage, to detect poor quality dermatology photos and to guide patients in taking better photos. Our experiments indicate that TrueImage can reject ~50% of the sub-par quality images, while retaining ~80% of good quality images patients send in, despite heterogeneity and limitations in the training data. These promising results suggest that our solution is feasible and can improve the quality of teledermatology care.

PRAME expression in melanocytic proliferations with intermediate histopathologic or spitzoid features

BACKGROUND

PRAME (PReferentially expressed Antigen in MElanoma) has shown utility in distinguishing melanoma from benign melanocytic lesions, but knowledge of its expression pattern in intermediate melanocytic and spitzoid proliferations is limited.

METHODS

Immunohistochemical expression of PRAME was examined in 112 melanocytic proliferations with intermediate histopathologic or spitzoid features.

RESULTS

Any intensity of nuclear PRAME staining in at least 60% of lesional melanocytes was determined as the best threshold for diffuse staining in this cohort. Nearly all non-spitzoid melanomas (23/24; 95.8%) demonstrated diffuse PRAME expression. PRAME was completely negative in 95.6% (43/45) of mitotically-active nevi, traumatized nevi, nevi with persistent/recurrent features, and dysplastic nevi. Most Spitz nevi (15/20) and atypical Spitz tumors (10/13) entirely lacked PRAME expression. One Spitz nevus, one atypical Spitz tumor, and one spitzoid melanoma (1/2) demonstrated diffuse PRAME expression.

CONCLUSIONS

Although diffuse PRAME expression is generally limited to malignant melanoma, benign Spitz nevi and atypical Spitz tumors can infrequently express diffuse PRAME. PRAME immunohistochemistry can be useful in the evaluation of atypical melanocytic proliferations with intermediate histopathologic features but should be interpreted with caution in the setting of spitzoid neoplasms.

Concurrent Trypanosoma cruzi and Cytomegalovirus Reactivation in an Immunosuppressed Patient With Limited Cutaneous Systemic Sclerosis

Chagas disease, a multisystem infection caused by the protozoan Trypanosoma cruzi, is primarily found in Latin America. In recent years, prevalence has increased in the United States, where reactivation is the most common clinical scenario. Here, we describe cutaneous reactivation of T. cruzi in a patient with limited cutaneous systemic sclerosis on immunosuppression therapy who simultaneously presented with cytomegalovirus reactivation. Histopathology showed parasitized histiocytes in the superficial and deep dermis. Occasional epidermal keratinocytes were also parasitized, and rare organisms were also seen in the walls of blood vessels. Also noted were viral cytopathic changes within the vascular endothelium, and immunostaining confirmed cytomegalovirus. In this report, we describe the difference in cutaneous findings between reactivated and acute Chagas disease, and we also review the histopathologic features that help distinguish T.cruzi from other intracellular organisms.

ALK-positive compound Spitz nevus with extensive perineural and intraneural neurotropism

Historically recognized by their characteristic histopathologic features, Spitz neoplasms are now known to be molecularly defined by mutually exclusive recurrent abnormalities that cause activation of the MAPK pathway. Spitz neoplasms with ALK rearrangements frequently demonstrate polypoid growth with a plexiform arrangement of nested, fusiform melanocytes in intersecting fascicles. Although neurotropism has been described in indolent Spitz neoplasms, this feature is not frequently mentioned in publications on histopathologic assessment of this group of melanocytic tumors. Here, we present an unusual case of a 3-year-old female with an ALK-positive compound Spitz nevus with extensive perineural and intraneural neurotropism occurring on the vermilion border of the lower lip.

Cutaneous T-cell lymphomas with pathogenic somatic mutations and absence of detectable clonal T-cell receptor gene rearrangement: two case reports

Background

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of extranodal non-Hodgkin lymphomas for which diagnosis can be challenging given the potential for overlap with inflammatory dermatoses. Current diagnostic criteria for CTCL incorporate clinical and histopathologic findings as well as results of T-cell receptor (TCR) gene sequencing. Molecular interrogation of TCR genes, TRG and TRB, has proven to be a critical tool for confirming diagnoses of CTCL and for disease tracking after initiation of therapy or after stem cell transplant. Methods for confirming a diagnosis of lymphoma in the absence of TCR gene clonality are lacking. We present two patients with CTCL with pathogenic somatic mutations in the absence of TRG and TRB clonality.

Case presentations

Case 1: A 38-year-old male had a 19-year history of a diffuse skin rash with papulosquamous, granulomatous, and verrucous features and progressive ulcerated plaques and tumors demonstrating an atypical CD4+ T-cell infiltrate with expression of cytotoxic markers CD56, TIA-1, granzyme, and perforin on histopathology. No definitive evidence for T-cell clonality was detected by conventional PCR of 6 biopsies or by next-generation sequencing (NGS) of 14 biopsies. Somatic mutational profiling of a skin biopsy revealed pathogenic mutations in PIKC3D and TERT promoter hotspots, confirming the presence of a clonal process. Case 2: A 69-year-old male with a 13-year history of progressive, diffuse hypertrophic and eroded plaques showed an atypical CD4+ T-cell infiltrate with subset expression of TIA-1 and granzyme on histopathology. No TCR clonality was detected by TCR-NGS of 6 biopsies. Somatic mutational profiling of a skin biopsy detected a pathogenic mutation in TP53, confirming the presence of a clonal process.

Conclusions

These cases highlight how detection of pathogenic somatic mutations can confirm a diagnosis of lymphoma in a clinically and histopathologically suspicious cutaneous lymphoid proliferation without detectable TCR clonality.

Differentiation syndrome during ivosidenib treatment with immunohistochemistry showing isocitrate dehydrogenase R132H mutation

We report a case of differentiation syndrome in a patient receiving the IDH1 inhibitor ivosidenib, with skin biopsy showing isocitrate dehydrogenase (IDH) R132H-mutated leukemia cutis. A 72-year-old man with IDH1-mutated acute myeloid leukemia (AML), status-post allogeneic cell transplantation, on ivosidenib for 6 months, was admitted for culture-negative neutropenic fever, pink and purpuric plaques and patches on the legs, abdomen and back, edema, hypotension, and shortness of breath. Skin biopsy revealed an infiltrate of atypical, immature, myeloperoxidase-positive mononuclear cells compatible with leukemia cutis or Sweet syndrome. Although dermal edema and interstitial neutrophilic infiltrate with karyorrhexis characteristic of Sweet syndrome were not seen, the atypical cells lacked expression of CD117 and CD34, which were expressed in the original leukemia. Additional immunohistochemical staining of suspected blasts was strongly positive for IDH1 R132H, suggesting a diagnosis of leukemia cutis. As the immunophenotype of blasts in skin infiltrates can significantly differ from the immunophenotype seen in blood and bone marrow, this case shows that mutation-specific antibodies such as anti-IDH1 R132H may be useful to help distinguish malignant from non-malignant infiltrates in the skin. Furthermore, differentiation syndrome may show histopathologic features of leukemia cutis on skin biopsy.

TERT and TERT promoter in melanocytic neoplasms: Current concepts in pathogenesis, diagnosis, and prognosis

BACKGROUND AND OBJECTIVE

Located on chromosome locus 5p15.33, telomerase reverse transcriptase (TERT or hTERT) encodes the catalytic subunit of telomerase which permits lengthening and preservation of telomeres following mitosis. Mutations in TERT promoter (TERT-p) upregulate expression of TERT, allowing survival of malignant cells and tumor progression in wide variety of malignancies including melanoma. The objective of this review is to examine the roles of TERT and TERT-p in the pathogenesis, diagnosis, and prognostication of cutaneous melanoma.

METHODS

All studies of TERT or TERT-p in cutaneous melanocytic neoplasms with the following inclusion criteria were reviewed: publication date between 2010 and 2019, English language, and series of ≥3 cases were reviewed for evidence supporting the role of TERT in pathogenesis, diagnosis, and prognosis. Studies with <3 cases or focused primarily on mucosal or uveal melanocytic tumors were excluded.

RESULTS AND CONCLUSION

TERT-p mutations are frequent in chronic and non-chronic sun damage melanoma and correlate with adverse prognosis, inform pathogenesis, and may provide diagnostic support. While TERT-p mutations are uncommon in acral melanoma, TERT copy number gains and gene amplification predict reduced survival. Among atypical spitzoid neoplasms, TERT-p mutations identify biologically aggressive tumors and support the diagnosis of spitzoid melanoma. TERT-p methylation may have prognostic value in pediatric conventional melanoma and drive tumorigenesis in melanoma arising within congenital nevi. Finally, TERT-p mutations may aid in the differentiation of recurrent nevi from recurrent melanoma.

Simultaneous coccidioidomycosis and phaeohyphomycosis in a kidney transplant recipient: A case report and literature review

Advances in solid organ transplantation have improved the survival of end-stage organ disease at the expense of an increased risk for opportunistic infections. Unusual clinical presentations and the possibility of concurrent infections make diagnosing invasive fungal infection (IFI) more difficult. Here, we present a case of simultaneous vertebral infection caused by Coccidioides immitis-posadasii and subcutaneous phaeohyphomycosis due to Nigrograna mackinnonii in a kidney transplant recipient. The diagnosis of both infections required invasive procedures to obtain tissue and a high index of suspicion that more than one IFI could be present. A multidisciplinary team approach for the management of immunocompromised patients with suspected or diagnosed IFI is warranted.

Disseminated tuberculosis presenting as medium-vessel vasculitis in an immunocompromised host

Cutaneous tuberculosis is an uncommon entity with several clinical forms recognized. Histopathologically, most cases are characterized by granulomatous inflammation and caseating necrosis, although less common findings, including vasculitis, have also been described. We report a 55-year-old male with a history of recently diagnosed dermatomyositis receiving immunosuppression with mycophenolate mofetil and prednisone, who developed multifocal soft tissue abscesses and an indurated erythematous plaque on the back. Skin biopsy of the back revealed a necrotizing medium-vessel vasculitis. Mycobacterium tuberculosis was detected in the skin via acid-fast bacilli stain and confirmed by tissue culture and polymerase chain reaction. Cutaneous findings improved rapidly with antituberculosis therapy. This case illustrates an uncommon clinical and histopathologic presentation of disseminated tuberculosis.

Artificial intelligence and dermatology: opportunities, challenges, and future directions

The application of artificial intelligence (AI) to medicine has considerable potential within dermatology, where the majority of diagnoses are based on visual pattern recognition. Opportunities for AI in dermatology include the potential to automate repetitive tasks; optimize time-consuming tasks; extend limited medical resources; improve interobserver reliability issues; and expand the diagnostic toolbox of dermatologists. To achieve the full potential of AI, however, developers must aim to create algorithms representing diverse patient populations; ensure algorithm output is ultimately interpretable; validate algorithm performance prospectively; preserve human-patient interaction when necessary; and demonstrate validity in the eyes of regulatory bodies.

Artificial intelligence and dermatology: opportunities, challenges, and future directions

The application of artificial intelligence (AI) to medicine has considerable potential within dermatology, where the majority of diagnoses are based on visual pattern recognition. Opportunities for AI in dermatology include the potential to automate repetitive tasks; optimize time-consuming tasks; extend limited medical resources; improve interobserver reliability issues; and expand the diagnostic toolbox of dermatologists. To achieve the full potential of AI, however, developers must aim to create algorithms representing diverse patient populations; ensure algorithm output is ultimately interpretable; validate algorithm performance prospectively; preserve human-patient interaction when necessary; and demonstrate validity in the eyes of regulatory bodies.

Paraneoplastic granulomatous dermatitis in a patient with Hodgkin's disease: a diagnostic pitfall

The association of malignant lymphomas with non-necrotic epithelioid granulomas has been reported rarely since 1977. Hodgkin's disease-associated widespread cutaneous granuloma annulare (GA) has been reported in only eight patients. We report the second case of subcutaneous GA associated with Hodgkin's disease. A 73-year-old man with Epstein-Barr virus-associated Hodgkin's lymphoma and paraneoplastic subcutaneous GA, presented 3 months after the diagnosis of malignancy. Examination revealed a large, broad erythematous, indurated, subcutaneous plaque spanning the majority of the left lower back and flank with no associated symptoms. Initial biopsy was suggestive of morphea. Prompted by positron emission tomography (PET) findings of increased fluorodeoxyglucose (FDG) uptake, a second, deeper biopsy was performed, revealing subcutaneous palisaded granulomatous dermatitis. After complete workup, the diagnosis most strongly suggested subcutaneous GA. This case highlights the importance of deep incisional biopsies, the fluorodeoxyglucose - positron emission tomography (FDG-PET) findings in GA and the rare association of GA with Hodgkin's disease which may signal the presence of malignancy.

Appropriate use criteria in dermatopathology: Initial recommendations from the American Society of Dermatopathology

BACKGROUND

Appropriate use criteria (AUC) provide physicians guidance in test selection, and can affect health care delivery, reimbursement policy, and physician decision-making.

OBJECTIVES

The American Society of Dermatopathology, with input from the American Academy of Dermatology and the College of American Pathologists, sought to develop AUC in dermatopathology.

METHODS

The RAND/UCLA appropriateness methodology, which combines evidence-based medicine, clinical experience, and expert judgment, was used to develop AUC in dermatopathology.

RESULTS

With the number of ratings predetermined at 3, AUC were developed for 211 clinical scenarios involving 12 ancillary studies. Consensus was reached for 188 (89%) clinical scenarios, with 93 (44%) considered "usually appropriate" and 52 (25%) "rarely appropriate" and 43 (20%) having "uncertain appropriateness."

LIMITATIONS

The methodology requires a focus on appropriateness without comparison between tests and irrespective of cost.

CONCLUSIONS

The ultimate decision to order specific tests rests with the physician and is one where the expected benefit exceeds the negative consequences. This publication outlines the recommendations of appropriateness-the AUC for 12 tests used in dermatopathology. Importantly, these recommendations may change considering new evidence. Results deemed "uncertain appropriateness" and where consensus was not reached may benefit from further research.

Development of RET mutant cutaneous angiosarcoma during BRAF inhibitor therapy

Treatment with BRAF inhibitors may lead to paradoxical mitogen-activated protein kinase (MAPK) pathway activation and accelerated tumorigenesis in cells with preexisting oncogenic hits. This phenomenon manifests clinically in the development of squamous cell carcinomas (SCCs) and keratoacanthomas (KAs) in patients treated with BRAF inhibitors. Cases of extracutaneous malignancies associated with BRAF inhibitors have also been reported. We present a case of a patient who developed a cutaneous angiosarcoma 6 months after initiation of vemurafenib therapy. Next-generation sequencing (NGS) revealed a mutation in RET, which lies upstream of the MAPK pathway. This case highlights that treatment with BRAF inhibitors may promote the accelerated growth of secondary malignancies. Physician awareness of the spectrum of secondary malignancies associated with BRAF inhibitor treatment will support their early detection and treatment.

Corrigendum: Dermatologist-level classification of skin cancer with deep neural networks

This corrects the article DOI: 10.1038/nature21056.

Dermatologist-level classification of skin cancer with deep neural networks

Skin cancer, the most common human malignancy, is primarily diagnosed visually, beginning with an initial clinical screening and followed potentially by dermoscopic analysis, a biopsy and histopathological examination. Automated classification of skin lesions using images is a challenging task owing to the fine-grained variability in the appearance of skin lesions. Deep convolutional neural networks (CNNs) show potential for general and highly variable tasks across many fine-grained object categories. Here we demonstrate classification of skin lesions using a single CNN, trained end-to-end from images directly, using only pixels and disease labels as inputs. We train a CNN using a dataset of 129,450 clinical images-two orders of magnitude larger than previous datasets-consisting of 2,032 different diseases. We test its performance against 21 board-certified dermatologists on biopsy-proven clinical images with two critical binary classification use cases: keratinocyte carcinomas versus benign seborrheic keratoses; and malignant melanomas versus benign nevi. The first case represents the identification of the most common cancers, the second represents the identification of the deadliest skin cancer. The CNN achieves performance on par with all tested experts across both tasks, demonstrating an artificial intelligence capable of classifying skin cancer with a level of competence comparable to dermatologists. Outfitted with deep neural networks, mobile devices can potentially extend the reach of dermatologists outside of the clinic. It is projected that 6.3 billion smartphone subscriptions will exist by the year 2021 (ref. 13) and can therefore potentially provide low-cost universal access to vital diagnostic care.

Gain of CD26 expression on the malignant T-cells in relapsed erythrodermic leukemic mycosis fungoides

Loss of CD26 surface expression on the circulating malignant T-cell is the most widely accepted diagnostic marker in patients with leukemic cutaneous T-cell lymphoma (CTCL). CTCL cases with reemergence of CD7 and/or CD26 surface expression are unusual and of uncertain prognosis. We report the case of an erythrodermic leukemic mycosis fungoides patient who had achieved temporary remission after several months on multimodality immunotherapy and extracorporeal photopheresis, but who relapsed with aggressive disease phenotypically characterized by CD4+ T-cells with high CD26 expression. Polymerase chain reaction studies and high-throughput sequencing analyses from peripheral blood mononuclear cells at presentation and relapse consistently showed an identical clonal T-cell receptor suggesting evolution of her original malignant clone which lacked CD26 expression. Interestingly, quantitative expression of the sialomucin, CD164, mirrored her clinical picture, thus favoring its reliability as a novel biomarker in CTCL.

Invasive Melanoma in a Patient with Congenital Ichthyosiform Erythroderma

We describe the case of a 26-year-old woman with a history of congenital ichthyosiform erythroderma (CIE) who initially presented with a stage IIA amelanotic melanoma on her forearm that was surgically excised. We also review the literature on CIE-associated skin cancers and discuss the possible contribution of ichthyosis to the risk of cutaneous malignancies. Our findings emphasize the importance of close lifelong skin cancer screening in individuals with CIE and highlight the unique malignancy risk of these individuals.

Sarcoidosis and squamous cell carcinoma: a connection documented in a case series of 3 patients

Sarcoidosis is a chronic multisystem disease characterized by the formation of noncaseating granulomas in multiple organs, including the skin. An association between multisystem sarcoidosis and an increased risk for malignancy has been established. Dermatologists should be aware of the increased risk for nonmelanoma skin cancers in patients with sarcoidosis. We report a series of 3 patients with primarily cutaneous sarcoidosis who presented with new-onset cutaneous squamous cell carcinoma (SCC). Two patients were black women and 1 patient presented with lesions of cutaneous sarcoidosis arising concurrently with SCCs in the same location, distinguishable only by biopsy. These cases highlight the association between sarcoidosis and an increased risk for SCC. Because dermatologists may be the primary clinicians caring for these patients, it is important that they remain aware of the increased risk for cutaneous malignancies and that they have a low threshold for biopsy of new and unusual skin lesions. Furthermore, 2 patients were black women, a population not commonly affected by skin cancer, which further exemplifies the need for comprehensive skin examinations in black patients. Although the precise mechanism for an increased risk for malignancy in these patients requires further investigation, chronic inflammation and immune dysregulation may play a role.

Low-dose radiotherapy for primary cutaneous anaplastic large-cell lymphoma while on low-dose methotrexate

Primary cutaneous anaplastic large-cell lymphoma (pcALCL) is part of a spectrum of CD30+ primary cutaneous lymphoproliferative disorders (pcLPDs) that also includes lymphomatoid papulosis (LyP). Localized radiotherapy at doses of 34 to 44 Gy is first-line treatment of pcALCL, but the use of low-dose radiotherapy for pcALCL has not been reported. We present the case of a patient with a history of pcALCL/LyP who was treated with low-dose radiotherapy while on oral low-dose methotrexate (MTX) once weekly. This report suggests that low-dose radiotherapy can be an effective palliative treatment of pcALCL. Low-dose radiotherapy may offer certain advantages over traditional radiotherapy, such as a more economical and efficient treatment for patients, potentially fewer short-term and long-term side effects, and the potential for concomitant use with low-dose MTX.

Epidermotropic metastasis of primary lung adenocarcinoma

Cutaneous metastasis of lung cancer is a rare event and usually portends a grim prognosis. Several cases of lung cancer with cutaneous metastasis have been reported, but these have been largely limited to the dermis. Here we describe a unique case of cutaneous metastatic lung adenocarcinoma largely limited to the epidermis, mimicking Paget's disease or a cutaneous adnexal tumor.

Immunohistochemical analysis of lichenoid reactions in patients treated with anti-PD-L1 and anti-PD-1 therapy

BACKGROUND

Recent advances in the immunotherapeutic treatment of cancer have led to the development of multiple new directed therapies including monoclonal antibodies that block the immune checkpoint T-cell receptor programmed death 1 (PD-1) and the PD-1 ligand, programmed death ligand 1 (PD-L1). Various immune-related toxicities have been associated with these drugs including, most commonly, skin rashes.

METHODS

Five cases of lichenoid dermatitis, including one case of lichenoid mucositis and one case of lichen sclerosus, associated with anti-PD-L1 and anti-PD1 therapy were compared with three biopsies of non-drug-related lichen planus (LP) and three lichen planus-like keratoses (LPLK) used as controls.

RESULTS

Histopathologic and immunophenotypic analysis of these lichenoid lesions demonstrated significantly greater histiocytic infiltrates than observed in control lichenoid reactions (p = 0.0134). We also observed increased spongiosis and epidermal necrosis. No significant differences were seen in expression of CD3, CD4:CD8, CD20, PD-1, CD25, Foxp3, CXCL13 and PD-L1 expression.

CONCLUSIONS

These findings expand the literature of immune-related toxicities of PD-L1 and PD-1 blockade to include lichenoid dermatitis and lichenoid mucositis. Of note, these cutaneous side effects were amenable to topical treatment, without the need for medication dose reduction or discontinuation.

Acquired port-wine stain with superimposed eczema following penetrating abdominal trauma

Port-wine stains (PWSs), or capillary malformations, are common congenital lesions, but acquired lesions rarely present in the setting of trauma. We present the case of an 18-year-old man who developed a PWS and associated localized eczema following penetrating trauma to the left abdomen. The diagnoses were confirmed on biopsy. The patient's eczema improved with topical steroids. Magnetic resonance imaging of PWSs is recommended in order to rule out deeper arteriovenous malformations. More research is needed to elucidate the connection between PWS pathophysiology and the development of eczema.

Presentation of Acute Megakaryoblastic Leukemia Associated with a GATA-1 Mutation Mimicking the Eruption of Transient Myeloproliferative Disorder

Children with trisomy 21 are prone to developing hematologic disorders, including transient myeloproliferative disorder (TMD) and acute megakaryoblastic leukemia (AMKL). The papulovesicular eruption of TMD provides an important clue to the diagnosis. In contrast, AMKL rarely has associated cutaneous findings. We report the case of a 22-month-old child with trisomy 21 who presented with the acute onset of diffusely scattered and crusted papules, plaques, and vesicles. A thorough infectious evaluation was negative and the patient was unresponsive to empiric antibiotic and antiinflammatory therapies. Complete blood count (CBC) was notable for mild pancytopenia, with a normal peripheral smear. Two weeks later he was reassessed and found to have a population of blasts on repeat CBC. Subsequent evaluation ultimately led to a diagnosis of AMKL. This is the first reported case of a cutaneous eruption in a young child with Down syndrome and transformed AMKL. When children with trisomy 21 present with the acute onset of crusted papules and vesicles that cannot be accounted for by an infectious etiology, a diagnosis of AMKL should be considered even in the absence of a history of TMD.