Case of a CIC::DUX4 fusion gene in a vascular neoplasm extends the spectrum of CIC-rearranged sarcomas.

CIC-rearranged sarcomas comprise a group of exceptionally aggressive round-cell sarcomas. These tumors most commonly demonstrate CIC::DUX4 fusion and show similar histopathology to Ewing sarcomas, though lesions mimicking vascular neoplasms have recently been described. Here, we describe a case of a patient with CIC::DUX4 fusion sarcoma identified using RNA-based molecular testing who was initially diagnosed with an endothelial neoplasm. The tumor showed extensive vasoformative growth, complete WT1 negativity, and global positive staining for ERG, CD31, and DUX4 by immunohistochemistry. Methylation testing of the tumor clustered more closely with angiosarcomas than with CIC-rearranged sarcomas. Our findings suggest that CIC::DUX4 fused neoplasms may demonstrate a more diverse phenotypic range than previously appreciated and offer evidence that both molecular and immunohistochemical studies are needed for accurate diagnosis.

EWSR1::NR4A3 gene fusion in a cutaneous atypical myoepithelial neoplasm.

Myoepithelial neoplasms of the skin and soft tissue are rare and share histopathologic features with their salivary gland counterpart. We present a case of an atypical myoepithelial neoplasm from the back of a 72-year-old female. This lesion harbored an EWSR1::NR4A3 gene fusion, a genetic signature characteristically seen in extraskeletal myxoid chondrosarcoma. To our knowledge, this is a unique case of an atypical cutaneous myoepithelial neoplasm harboring EWSR1::NR4A3 fusion.

Application of immunohistochemical studies in diagnosing emerging superficial mesenchymal neoplasms.

Molecular diagnostics, with the subsequent development of novel immunohistochemical markers, continues to advance and expand the field of soft tissue pathology. As such, the ever-evolving molecular diagnostic landscape will continue to shape and refine our understanding and classification of neoplasms. This article reviews the current literature on various tumors of mesenchymal origin, including fibroblastic/fibrohistiocytic, adipocytic, vascular, and tumors of uncertain origin. We aim to give the reader a detailed understanding and pragmatic approach to various new and established immunohistochemical stains in diagnosing these neoplasms and also discuss various pitfalls with significant repercussions.

Clinical and direct immunofluorescence characteristics of cutaneous toxicity associated with enfortumab vedotin.

Enfortumab vedotin (EV), a novel antibody-drug conjugate approved for metastatic urothelial carcinoma, causes a variety of cutaneous adverse reactions. We present two cases of bullous eruptions following treatment with EV, both demonstrating IgG deposition on direct immunofluorescence (DIF) correlating to the location of nectin-4 in the epidermis. This suggests that the IgG component of EV binding to nectin-4 in keratinocytes is likely a primary contributor to the high rates of cutaneous toxicity.

The Role of T Helper Type 2 (Th2) Cytokines in the Pathogenesis of Eosinophilic Granulomatosis with Polyangiitis (eGPA): an Illustrative Case and Discussion.

PURPOSEOF REVIEW: The pathogenesis of eosinophilic granulomatosis with polyangiitis (eGPA) is driven largely by CD4 + type 2 helper T cells (Th2), B cells, and eosinophils. Interleukin (IL)-4 and IL-13 are critical cytokines in Th2 cell-mediated inflammation; however, inhibition of IL-4 and IL-13 does not reduce serum eosinophil counts and has even been associated with hypereosinophilia. This review explores the role of IL-4, IL-5, and IL-13 in Th2-mediated inflammation to consider the potential clinical consequences of inhibiting these individual cytokines in eGPA. RECENT FINDINGS: Treatments for eosinophilic granulomatosis with polyangiitis (eGPA) are rapidly evolving through using biologic therapies to modulate the Th2 inflammatory response via eosinophil inhibition. While IL-4, IL-5, IL-13, and IL-25 can all affect eosinophils, only IL-5 inhibition has demonstrated therapeutic benefit to-date. In this review, we report a clinical vignette of a patient with adult-onset asthma who developed severe manifestations of eGPA after switching from mepolizumab (an IL-5 inhibitor) to dupilumab (an inhibitor of IL-4 and IL-13). By understanding the role of IL-4, IL-5, and IL-13 in Th2-mediated vasculitis, we can start to understand how eGPA might respond differently to focused cytokine inhibition.

Cutaneous inflammatory myofibroblastic tumor with CARS-ALK fusion: Case report and literature review.

Cutaneous inflammatory myofibroblastic tumors (IMT) constitute a rare entity, generating a diagnostic pitfall when diagnosing spindle cell proliferation within the dermis. Raising awareness of this tumor among dermatopathologists remains vital in differentiating it from common cutaneous tumors such as fibrous histiocytoma, atypical fibroxanthoma, melanoma, poorly differentiated carcinoma, and other more aggressive tumors. Accurate diagnosis of IMT aids in ensuring appropriate management and follow-up for patients while preventing unnecessary harm and overtreatment. Here we report a case of a 38-year-old female with a painless, slow-growing nodule of the left posterior scalp initially diagnosed as a dermatofibroma. The histopathological examination revealed an ill-defined dermal nodule of spindled cells without connection or infiltration of the epidermis. At high power, the cells were arranged in fascicles with a prominent background of lymphocytic infiltrate. Immunohistochemical analysis showed strong diffuse immunoreactivity for anaplastic lymphoma kinase (ALK), and targeted RNA sequencing identified a CARS-ALK fusion ultimately confirming the accurate diagnosis of a cutaneous IMT.

A Case of Congenital Syphilis-Focus on Histopathology and Literature Review.

ABSTRACT: Although a rare disease, the incidence of congenital syphilis is on the rise in the US. We report a case of early congenital syphilis in a 1-day-old premature boy with positive Rapid plasma reagin titer, respiratory insufficiency, disseminated intravascular coagulation, and encephalopathy, born to a mother with known syphilis infection. Skin examination showed diffuse truncal petechiae, desquamation of the distal extremities, and violaceous, retiform plaques on the buttocks and lower extremities. A biopsy was performed to rule out an infectious etiology or vasculitis. Histopathologic examination revealed irregular epidermal acanthosis with orthokeratosis and parakeratosis. There were foci of neutrophilic infiltrate forming rare pustules within the stratum corneum and focal intraepidermal eosinophils, neutrophils, and rare dyskeratotic keratinocytes. In the dermis, there was some minimal endothelial swelling with a perivascular, interstitial, and periadnexal infiltrate of lymphocytes, eosinophils, and rare plasma cells. A Treponema pallidum immunostain highlighted spirochetes present within the epidermis and within the eccrine ducts. Penicillin G therapy was administered for 10 days. The infant's Rapid plasma reagin titer trended downward until it was negative 6 months after birth. Literature review reveals 8 case reports within the last 20 years describing the histopathology of rashes in congenital syphilis. Herein we summarize the reported histopathology of rashes in congenital syphilis and compare it to the histopathology of rashes in secondary syphilis in adults.

Characterization of Sentinel Lymph Node Immune Signatures and Implications for Risk Stratification for Adjuvant Therapy in Melanoma.

BACKGROUND: Although sentinel lymph node (SLN) biopsy is a standard procedure used to identify patients at risk for melanoma recurrence, it fails to risk-stratify certain patients accurately. Because processes in SLNs regulate anti-tumor immune responses, the authors hypothesized that SLN gene expression may be used for risk stratification. METHODS: The Nanostring nCounter PanCancer Immune Profiling Panel was used to quantify expression of 730 immune-related genes in 60 SLN specimens (31 positive [pSLNs], 29 negative [nSLNs]) from a retrospective melanoma cohort. A multivariate prediction model for recurrence-free survival (RFS) was created by applying stepwise variable selection to Cox regression models. Risk scores calculated on the basis of the model were used to stratify patients into low- and high-risk groups. The predictive power of the model was assessed using the Kaplan-Meier and log-rank tests. RESULTS: During a median follow-up period of 6.3 years, 20 patients (33.3%) experienced recurrence (pSLN, 45.2% [14/31] vs nSLN, 20.7% [6/29]; p = 0.0445). A fitted Cox regression model incorporating 12 genes accurately predicted RFS (C-index, 0.9919). Improved RFS was associated with increased expression of TIGIT (p = 0.0326), an immune checkpoint, and decreased expression of CXCL16 (p = 0.0273), a cytokine important in promoting dendritic and T cell interactions. Independent of SLN status, the model in this study was able to stratify patients into cohorts at high and low risk for recurrence (p < 0.001, log-rank). CONCLUSIONS: Expression profiles of the SLN gene are associated with melanoma recurrence and may be able to identify patients as high or low risk regardless of SLN status, potentially enhancing patient selection for adjuvant therapy.

Cutaneous involvement by T-cell prolymphocytic leukemia presenting as livedoid vasculopathy.

T-cell prolymphocytic leukemia (T-PLL) is a rare, aggressive neoplasm derived from post-thymic T-cells. Patients are typically middle aged with a slight male predominance who present with a high white blood cell count, hepatosplenomegaly, lymphadenopathy, and other symptoms typically associated with leukemia. Although cutaneous involvement has been reported in up to 30% of cases of T-PLL, to our knowledge, none have presented with a presentation resembling livedoid vasculopathy. In the correct clinical context, an underlying hematolymphoid neoplasm should be included in the differential diagnosis of a patient presenting with livedoid vasculopathy.

Diagnosis of melanoma by imaging mass spectrometry: Development and validation of a melanoma prediction model.

BACKGROUND: The definitive diagnosis of melanocytic neoplasia using solely histopathologic evaluation can be challenging. Novel techniques that objectively confirm diagnoses are needed. This study details the development and validation of a melanoma prediction model from spatially resolved multivariate protein expression profiles generated by imaging mass spectrometry (IMS). METHODS: Three board-certified dermatopathologists blindly evaluated 333 samples. Samples with triply concordant diagnoses were included in this study, divided into a training set (n = 241) and a test set (n = 92). Both the training and test sets included various representative subclasses of unambiguous nevi and melanomas. A prediction model was developed from the training set using a linear support vector machine classification model. RESULTS: We validated the prediction model on the independent test set of 92 specimens (75 classified correctly, 2 misclassified, and 15 indeterminate). IMS detects melanoma with a sensitivity of 97.6% and a specificity of 96.4% when evaluating each unique spot. IMS predicts melanoma at the sample level with a sensitivity of 97.3% and a specificity of 97.5%. Indeterminate results were excluded from sensitivity and specificity calculations. CONCLUSION: This study provides evidence that IMS-based proteomics results are highly concordant to diagnostic results obtained by careful histopathologic evaluation from a panel of expert dermatopathologists.

Cutaneous metastasis of SMARCA4-deficient thoracic sarcoma: A diagnostic dilemma with therapeutic implications.

SMARCA4-deficient thoracic sarcoma (SMARCA4-DTS) is a recently recognized entity with undifferentiated rhabdoid morphology and mutations in the switch/sucrose nonfermenting BRG1-associated factors complex. Patients are typically males in their fifth decade with a history of smoking who present with rapidly progressive intrathoracic disease and follow an aggressive clinical course. Metastatic disease is reported in up to 77% of cases; however, to our knowledge, cutaneous metastasis has not been reported nor has it been reported as the initial manifestation of the disease. Recognizing SMARCA4-DTS from other types of epithelioid tumors that involve the skin is clinically relevant, as targeted therapies for SMARC-deficient tumors are currently being investigated and early clinical trial data show therapeutic benefit.

Trichoblastic carcinosarcoma: A case report and literature review.

Trichoblastic carcinosarcoma is a rare biphasic adnexal neoplasm. This case report chronicals the eighth occurrence of this tumor published in the English literature and provides a review of the prior publications. Clinically, this tumor presents as an isolated, rapidly growing lesion in elderly patients and is usually cured by complete surgical excision, with no evidence of recurrence or metastasis at follow-up (7/8 cases). Histopathologically, trichoblastic carcinosarcoma is dermal-based, with an epithelial component of basal cells and a mesenchymal component of spindle cells, both of which display malignant features. In addition to a morphologic description of trichoblastic carcinosarcoma, a discussion of the differential diagnoses, including other biphasic neoplasms, is also included. The small number of cases of trichoblastic carcinosarcoma is most likely secondary to under-recognition and underreporting and a larger case volume is needed to more accurately assess the clinical course and treatment strategies.

Successful Treatment of Painful Cutaneous Vasculopathy With Rivaroxaban in a Patient With Systemic Lupus Erythematosus.

Novel oral anticoagulant (NOAC) medications have revolutionized hematology and cardiology. Recently, NOACs have demonstrated additional promise in dermatology. Specifically, rivaroxaban, a direct factor Xa inhibitor NOAC, has been shown to be successful in the treatment of livedoid vasculopathy. Herein, we describe a patient with systemic lupus erythematosus who presented with painful cutaneous vasculopathy, demonstrated on biopsy with occlusive microvascular fibrin thrombi without evidence of concurrent vasculitis. Interestingly, imaging and laboratory studies did not show evidence of hypercoagulability, arterial disease, or embolic disease. The patient’s vasculopathy and pain progressed despite antiplatelet therapy, often considered first-line in cases of microvascular occlusive disease. However, with rivaroxaban therapy, the patient experienced complete regression of her painful lesions, thereby supporting a further role for NOACs in cutaneous vasculopathy treatment. J Drugs Dermatol. 2020;19(5) doi:10.36849/JDD.2020.4684.

Low-grade fibromyxoid sarcoma of acral sites: Case report and literature review.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue sarcoma that usually presents as a deep-seated tumor in young adults; however, they can occur on superficial sites, mostly documented in pediatric age groups. LGFMS presenting on acral sites is not highly emphasized in the general pathology or dermatopathology literature. The case presented is that of a 30-year-old man with a foot mass that was removed 15 years earlier and subsequently recurred as two masses, the first occurring between the third and fourth toes/metatarsal region and the second over the lateral tarsal region. An excisional biopsy showed a relatively circumscribed, bland spindle cell proliferation with hypocellular and hypercellular zones. The cells showed minimal pleomorphism and lacked mitotic activity. Immunohistochemical analysis showed immunoreactivity for MUC4 and break-apart fluorescence in situ hybridization was positive for FUS rearrangement, confirming the diagnosis of LGFMS. There are multiple spindle cell tumors that occur on acral sites which usually generates a list of differential diagnoses; however, LGFMS is not usually discussed in that anatomic location. Awareness of the occurrence of LGFMS on acral sites is important to avoid misdiagnosis of this deceptively benign-appearing tumor.

Dermal xanthomatous infiltrates after brentuximab vedotin therapy in mycosis fungoides with large-cell transformation: A novel histologic finding.

Mycosis fungoides (MF) is the most common variant of cutaneous T-cell lymphomas. Large-cell transformation of MF has been associated with disease progression and overall poor outcome. The expression of CD30, which defines anaplastic large cell lymphoma (ALCL) and lymphomatoid papulosis, might also occur in a subset of patients with MF, with or without large-cell transformation. Brentuximab vedotin is an anti-CD30 monoclonal antibody which has been proven to be a safe and effective therapeutic agent in the treatment of CD30-positive lymphomas, such as Hodgkin lymphoma and ALCL. Recently, brentuximab vedotin has been shown to have a significant clinical activity in treatment-refractory or advanced MF or Sezary syndrome with a wide-range of CD30 expression levels. We report a patient with MF tumor stage with large-cell transformation and low CD30 expression with good response to brentuximab vedotin and unusual extensive xanthomatous changes in the follow-up biopsy.

Cutaneous Angiosarcoma of the Eyelid Mimicking Morbihan Disease.

BACKGROUND: Cutaneous angiosarcoma presents clinically in numerous ways, and can be mistaken for a different clinical entity, particularly when arising at unusual anatomic locations such as the eyelid. CASE PRESENTATION: A 57-year-old woman presented with a 1-year history of eyelid swelling. Concurrent imaging was also suggestive of an edematous process. Multiple superficial biopsies showed nonspecific dermal inflammation and interstitial edema. A diagnosis of Morbihan disease (chronic and idiopathic lymphedema of the eyelid) was rendered, and the patient was treated with compression and local therapy without clinical improvement. Three years after initial presentation, a diagnostic blepharoplasty was performed revealing a deep dermal vascular proliferation composed of anastomosing vascular channels with an atypical endothelial lining. A diagnosis of cutaneous angiosarcoma was ultimately made. CONCLUSIONS: This case illustrates a unique presentation of cutaneous angiosarcoma and the implications of different biopsy techniques in acquiring the correct diagnosis.

Cutaneous polyarteritis nodosa localized to a region of lymphedema secondary to Streptococcus viridans cellulitis and multiple surgeries.

Cutaneous polyarteritis nodosa (CPAN) is a chronic, indolent, single organ arteritis that generally presents with lower extremity nodules and/or livedo racemosa, accompanied by malaise and arthralgias. CPAN is often triggered by infection, commonly Group A streptococcal species, and is considered an autoimmune reaction. Scarring from surgery and obliterative lymphangiitis from bacterial cellulitis are the causes of lymphedema. Lymphedematous skin is predisposed to autoimmune disorders. Herein we report a 53-year-old woman who developed CPAN restricted to a localized area of the right upper arm-shoulder that had undergone multiple surgeries, complicated by episodes of Streptococcus viridans cellulitis. Clinically, a 15 cm diameter plaque exhibited violaceous, reticulate margins, subtle papules and nodules and central livedo racemosa. Biopsy showed numerous foci of arteritis in active, subacute and reparative stages. In addition, a broad zone of fibrosis replaced the deep dermis-subcutis zone and harbored numerous dilated lymphatic vessels scar lymphedema. Treatment consisted of high potency topical corticosteroids under occlusion; remission after 3 months therapy and follow-up. CPAN primarily affects the lower legs, a region of frequently affected by phlebolymphedema. This report of CPAN localized to an area of scar lymphedema underscores the importance of lymphatic function in the pathogenesis of CPAN.

Evaluation of 122 advanced-stage cutaneous squamous cell carcinomas by comprehensive genomic profiling opens the door for new routes to targeted therapies.

BACKGROUND: The authors hypothesized that comprehensive genomic profiling of advanced-stage cutaneous squamous cell carcinoma (cSCC) could identify genomic-derived drug targets of therapy for patients with conventional therapy-resistant disease. METHODS: Comprehensive genomic profiling of 315 cancer genes was applied to 50 ng of DNA from 122 cSCC cases for the evaluation of all classes of genomic alterations (GAs). Clinically relevant genomic alterations (CRGAs) were defined as those identifying anticancer drugs on the market or in registered clinical trials. RESULTS: There were 21 women (17%) and 101 men (83%) with a median age of 64.9 years (range, 21-87 years). Eleven cSCC cases (9%) were histologic AJCC grade 1, 69 (57%) were grade 2, and 42 (34%) were grade 3. The primary cSCC was used for sequencing in 77 cases (63%). Metastatic lesions were sequenced in 37% of cases. There were 1120 total GAs identified (average of 9.2 GAs per tumor), with 100% of cases harboring at least 1 alteration. Of the 122 cSCCs, 107 (88%) harbored at least 1 CRGA (2.5 CRGAs per cSCC) includingNOTCH1 (43%); patched 1 (PTCH1) (11%); BRCA2 (10%); HRAS (8%); ataxia telangiectasia mutated (ATM) (7%); erb-B2 receptor tyrosine kinase 4 (ERBB4) (7%); neurofibromatosis type 1 (NF1) (7%); erb-B2 receptor tyrosine kinase 2 (ERBB2) (6%); phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) (6%); cyclin D1 (CCND1) (6%); epidermal growth factor receptor (EGFR) (5%); and F-box and WD repeat domain containing 7, E3 ubiquitin protein ligase (FBXW7) (5%). CONCLUSIONS: In the current study, approximately 88% of patients with cSCC were found to harbor clinically relevant GAs that have the potential to guide the treatment of patients with advanced-stage tumors with targeted therapeutic agents. Cancer 2016;122:249-257. © 2015 American Cancer Society.