Use of UV mutational signatures to distinguish between cutaneous and pulmonary primary squamous cell carcinoma.

BACKGROUND: Squamous cell carcinoma (SCC) of presumed lung origin (PLO) is now the second most frequent histologic subtype of non-small cell carcinoma after adenocarcinoma. The use of clinic-genomic correlation provided by comprehensive genomic profiling (CGP) can revise clinicopathologic diagnoses of presumed primary lung SCC (PLO-SCC) to diagnoses of metastatic SCC of cutaneous origin (C-SCC). DESIGN: A total of 10 146 samples of clinically advanced PLO-SCC (84% known Stage IV) passed QC metrics and were designated as PLO-SCCs by review of test requisition forms, clinical notes, and pathology reports. One thousand seven hundred sixty-one cases of known primary C-SCC were also included in this study. All samples underwent hybrid capture-based CGP (Foundation Medicine, Inc.) using a targeted gene panel to evaluate all classes of genomic alterations (GA), determine MSI, TMB, and genomic ancestry status. The mutational signature (MS) of each case was called by the decomposition method using reference signatures in the COSMIC database. PD-L1 tumor cell expression was determined by IHC (22C3; Dako). All results were compared using the Fisher exact method with the false discovery rate corrected with a Benjamini-Hochberg adjustment. RESULTS: A total of 253 of 10 146 (2.5%) PLO-SCC cases featured a UV+ MS; 812 of 1761 C-SCC (46.1%) that also featured a UV radiation exposure MS (UV+) were also included in this study. PLO-SCC UV+ cases used for sequencing included tissue samples from the lung (162), lymph node (34), soft tissue (33), liver (8), head and neck (7), brain (5), and skin thought to be metastatic sites from primary lung SCC (4). The PLO-SCC UV+ patients were 78.7% male and had a median age of 72 years, which was younger and more frequently male gender than both the C-SCC UV+ and C-SCC UV- patients (p < 0.0001). Both the PLO-SCC UV+ and C-SCC UV+ featured greater GA per tumor than the PLO-SCC UV- cases (p < 0.0001). In the PLO-SCC UV- cases, tobacco exposure and APOBEC were the most frequent MSs. For the biomarkers associated with immune checkpoint inhibitor efficacy, when compared with the PLO-SCC UV- cases, the PLO-SCC UV+ cases featured more cases with TMB ≥10 mutations/Mb (88.5% vs. 36.5%; p < 0.0001) and ≥20 mutations/Mb (66.8% vs. 6.8%; p < 0.0001) and a trend for less frequent positive PD-L1 (≥50% TPS) IHC staining (30.2% vs. 39.6%; p = 0.062). Compared to PLO-SCC UV- cases, PLO-SCC UV+ and C-SCC UV+ cases were more likely to harbor clinically-actionable GA in PTCH1 and NOTCH1/2 (p < 0.0001) and less likely to harbor clinically-actionable GA in KRAS, PIK3CA, and PTEN (p < 0.0001). The frequency of PTCH1 GA in PLO-SCC UV+ (32% vs. 0.9% in PLO-SCC UV-) suggested that PLO-SCC UV+ may include a mixture of C-SCC and cutaneous basal cell carcinomas (C-BCC) with squamous differentiation. CONCLUSIONS: When cases of PLO-SCC undergo CGP, a small 2.5% subset of cases that featured a UV MS emerge that indicates that these tumors may actually represent metastatic cutaneous SCC or BCC with squamous differentiation. Given the significant treatment and clinical impact associated with the resolution of the true diagnosis of these cases, the use of genomic sequencing in PLO-SCC may be clinically beneficial.

Cladribine Use in Xanthoma Disseminatum: A Rare Case Presentation and Brief Updated Literature Review.

Xanthoma disseminatum (XD) is a rare, non-Langerhans cell histiocytosis. While treatment is notoriously difficult, 2-chlorodeoxyadenosine (cladribine) has recently emerged as a potential effective therapeutic option. Here, we describe the case of a 65-year-old male with XD who experienced significant cutaneous improvement after cladribine treatment. We also provide an updated literature review on cladribine use in patients with XD in light of reported adverse effects (AEs). While the efficacy of cladribine in XD is clear, no consensus exists for treatment duration and AE management. Hence, we strongly encourage interdisciplinary discourse involving dermatology and oncology in these cases.

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.

Stage III Melanoma: A Proposed Staging Model That Outperforms the American Joint Committee on Cancer Eighth Edition Staging System.

National Comprehensive Cancer Network guidelines state that clinical stage III melanoma patients may undergo ultrasound surveillance of the nodal basin in lieu of complete lymph node dissection (CLND). This has led to an inability to accurately classify patients according to the American Joint Committee on Cancer (AJCC) eighth edition staging system because it uses the total number of positive lymph nodes from the CLND to assign a pathologic N stage. We propose a new model for clinical stage III melanoma patients that does not rely on the total number of positive lymph nodes. Instead, it uses Breslow depth, ulceration status, sentinel lymph node metastasis size, and extracapsular extension to stratify patients into groups 1 to 4. We compared our model's ability to predict melanoma-specific survival (MSS), distant metastasis-free survival (DMFS) and locoregional recurrence, and distant metastasis-free survival (DMFS-LRFS) to the current AJCC system with and without CLND-data using a Cox proportional hazards model and Akaike Information Criteria weights. Although not reaching our predetermined level of statistical significance of 95%, our model was 5 times more likely to better predict MSS compared with the AJCC model with CLND. In addition, our model was significantly better than the AJCC model without CLND in predicting MSS. Our model performed significantly better than the AJCC model in predicting DMFS and DMFS-LRFS regardless of whether data from CLND were included.

Clinicopathologic correlation of dermatologic diseases in patients with darker pigmentation.

OBJECTIVES: Cutaneous diseases that disproportionately affect patients with darker pigmentation and their histologic features are historically understudied and undertreated. This review article aims to highlight the key clinical features, histopathology, and diagnostic pearls of several cutaneous diseases that commonly present in patients with darker pigmentation. METHODS: A literature search was conducted, and a list of cutaneous diseases that frequently affect patients with darker pigmentation was compiled. A group of experts expounded upon those that were most common or misdiagnosed according to scientific evidence and clinical practice. RESULTS: The diseases were divided into hypopigmented disorders, hyperpigmented disorders, scarring disorders, and alopecic disorders. Within each category, the etiology, clinical features, histopathology, and key histologic differential diagnoses are described and discussed. CONCLUSIONS: As many clinicians are taught that there are no effective treatment options or that these diseases are considered "cosmetic" in nature, patients often do not get a thorough medical workup or skin biopsy. This article aims to decrease the knowledge gap and serve as a resource for anyone involved in the care of patients with these cutaneous conditions.

Pediatric Atypical Melanocytic Proliferations: Single-Site Retrospective Cohort Assessment of Treatment and Long-Term Follow-Up.

Atypical and malignant cutaneous tumors are understudied in the pediatric population, with limited data on long-term follow-up. This study examines pediatric (0-18 years) atypical melanocytic proliferations over a twenty-year period (January 2002-December2022) using the EPIC SlicerDicer at our institution. Over a twenty-year period, there were 55 cases of pediatric melanoma (53 patients). The median follow-up time was 8 years, 11 months. A proportion of 96% were treated with wide local excision (WLE), and 47% had a sentinel lymph node biopsy (SLNB) (35% positive rate). There were 101 atypical Spitz tumor cases (85% atypical Spitz tumors, 15% Spitz melanoma), with a median follow-up duration of 9 years. A proportion of 77% were treated with WLE (with one patient dying of metastatic disease). There were 10 cases of atypical melanocytic proliferations not otherwise specified, including 5 pigmented epithelioid melanocytomas (PEM), 4 deep-penetrating nevi, and 1 atypical cellular blue nevus. This study adds to the growing body of knowledge on pediatric atypical cutaneous melanocytic proliferations, aligning with many described characteristics such as disease location and overall survival rates, with distinct exceptions (higher melanoma positive SLNB rate, lower atypical Spitz tumor WLE rate, and a case of fatal metastatic atypical Spitz tumor).

Giant cell tumor of bone in the pediatric population: a retrospective study highlighting cases of metaphyseal only location and increased local recurrence rates in skeletally immature patients.

OBJECTIVE: To describe the presentation of giant cell tumors (GCT) of the bone in the pediatric population to (1) improve the differential diagnosis of pediatric bone tumors and (2) identify the origin of GCT. Understanding the origin of bone tumors assists in establishing appropriate diagnoses and recommending treatment options. This is particularly important in children, where evaluating the need for invasive procedures is balanced with the desire to avoid overtreatment. GCT have historically been considered epiphyseal lesions with potential metaphyseal extension. Therefore, GCT may be inappropriately excluded from the differential diagnosis of metaphyseal lesions in the skeletally immature. MATERIALS AND METHODS: We identified 14 patients from 1981 to 2021 at a single institution who had histologic confirmation of GCT and were less than 18 years old at diagnosis. Patient characteristics, tumor location, surgical treatment, and local recurrence rates were collected. RESULTS AND CONCLUSIONS: Ten (71%) patients were female. Eleven (78.6%) were epiphysiometaphyseal (1 epiphyseal, 4 metaphyseal, 6 epiphysiometaphyseal). Five patients had an open adjacent physis, of which three (60%) had tumors confined solely to the metaphysis. Of the five patients with open physis, four (80%) developed local recurrence while only one patient (11%) with a closed physis had local recurrence (p value = 0.0023). Our results illustrate that for the skeletally immature, GCT can (and in our results more commonly did) occur in the metaphyseal location. These findings suggest that GCT should be included in the differential diagnosis of primary metaphyseal-only lesions in the skeletally immature.

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.

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.

A Case of Multiple Hemorrhagic Friable Nodules.

A man in his 50s with a history of mycosis fungoides presents with bleeding wounds and nodules on the bilateral hips and forearms. What is your diagnosis?

Tumor-intrinsic NLRP3-HSP70-TLR4 axis drives premetastatic niche development and hyperprogression during anti-PD-1 immunotherapy.

The tumor-intrinsic NOD-, LRR- and pyrin domain-containing protein-3 (NLRP3) inflammasome-heat shock protein 70 (HSP70) signaling axis is triggered by CD8+ T cell cytotoxicity and contributes to the development of adaptive resistance to anti-programmed cell death protein 1 (PD-1) immunotherapy by recruiting granulocytic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) into the tumor microenvironment. Here, we demonstrate that the tumor NLRP3-HSP70 axis also drives the accumulation of PMN-MDSCs into distant lung tissues in a manner that depends on lung epithelial cell Toll-like receptor 4 (TLR4) signaling, establishing a premetastatic niche that supports disease hyperprogression in response to anti-PD-1 immunotherapy. Lung epithelial HSP70-TLR4 signaling induces the downstream Wnt5a-dependent release of granulocyte colony-stimulating factor (G-CSF) and C-X-C motif chemokine ligand 5 (CXCL5), thus promoting myeloid granulopoiesis and recruitment of PMN-MDSCs into pulmonary tissues. Treatment with anti-PD-1 immunotherapy enhanced the activation of this pathway through immunologic pressure and drove disease progression in the setting of Nlrp3 amplification. Genetic and pharmacologic inhibition of NLRP3 and HSP70 blocked PMN-MDSC accumulation in the lung in response to anti-PD-1 therapy and suppressed metastatic progression in preclinical models of melanoma and breast cancer. Elevated baseline concentrations of plasma HSP70 and evidence of NLRP3 signaling activity in tumor tissue specimens correlated with the development of disease hyperprogression and inferior survival in patients with stage IV melanoma undergoing anti-PD-1 immunotherapy. Together, this work describes a pathogenic mechanism underlying the phenomenon of disease hyperprogression in melanoma and offers candidate targets and markers capable of improving the management of patients with melanoma.

Multimodality analysis confers a prognostic benefit of a T-cell infiltrated tumor microenvironment and peripheral immune status in patients with melanoma.

BACKGROUND: We previously reported results from a phase 1 study testing intratumoral recombinant poliovirus, lerapolturev, in 12 melanoma patients. All 12 patients received anti-PD-1 systemic therapy before lerapolturev, and 11 of these 12 patients also received anti-PD-1 after lerapolturev. In preclinical models lerapolturev induces intratumoral innate inflammation that engages antitumor T cells. In the current study, prelerapolturev and postlerapolturev tumor biopsies and blood were evaluated for biomarkers of response. METHODS: The following analyses were performed on tumor tissue (n=11): (1) flow cytometric assessment of immune cell density, (2) NanoString Digital Spatial profiling of protein and the transcriptome, and (3) bulk RNA sequencing. Immune cell phenotypes and responsiveness to in vitro stimulation, including in vitro lerapolturev challenge, were measured in peripheral blood (n=12). RESULTS: Three patients who received anti-PD-1 therapy within 30 days of lerapolturev have a current median progression-free survival (PFS) of 2.3 years and had higher CD8+T cell infiltrates in prelerapolturev tumor biopsies relative to that of 7 patients with median PFS of 1.6 months and lower CD8+T cell infiltrates in prelerapolturev tumor biopsies. In peripheral blood, four patients with PFS 2.3 years (including three that received anti-PD-1 therapy within 30 days before lerapolturev and had higher pretreatment tumor CD8+T cell infiltrates) had significantly higher effector memory (CD8+, CCR7-, CD45RA-) but lower CD8+PD-1+ and CD4+PD-1+ cells compared with eight patients with median PFS 1.6 months. In addition, pretreatment blood from the four patients with median PFS 2.3 years had more potent antiviral responses to in vitro lerapolturev challenge compared with eight patients with median PFS 1.6 months. CONCLUSION: An inflamed pretreatment tumor microenvironment, possibly induced by prior anti-PD-1 therapy and a proficient peripheral blood pretreatment innate immune response (antiviral/interferon signaling) to lerapolturev was associated with long term PFS after intratumoral lerapolturev in a small cohort of patients. These findings imply a link between intratumoral T cell inflammation and peripheral immune function. TRIAL REGISTRATION NUMBER: NCT03712358.

Spatial biology analysis reveals B cell follicles in secondary lymphoid structures may regulate anti-tumor responses at initial melanoma diagnosis.

Introduction: B cells are key regulators of immune responses in melanoma. We aimed to explore differences in the histologic location and activation status of B cell follicles in sentinel lymph nodes (SLN) of melanoma patients. Methods: Flow cytometry was performed on fresh tumor draining lymph nodes (LN). Paraffin slides from a separate cohort underwent NanoString Digital Spatial Profiling (DSP)®. After staining with fluorescent markers for CD20 (B cells), CD3 (T cells), CD11c (antigen presenting cells) and a nuclear marker (tumor) was performed, regions of interest (ROI) were selected based on the location of B cell regions (B cell follicles). A panel of 68 proteins was then analyzed from the ROIs. Results: B cell percentage trended higher in patients with tumor in LN (n=3) compared to patients with nSLN (n=10) by flow cytometry. B cell regions from a separate cohort of patients with tumor in the (pSLN) (n=8) vs. no tumor (nSLN) (n=16) were examined with DSP. Within B cell regions of the SLN, patients with pSLN had significantly higher expression of multiple activation markers including Ki-67 compared to nSLN patients. Among 4 patients with pSLN, we noted variability in arrangement of B cell follicles which were either surrounding the tumor deposit or appeared to be infiltrating the tumor. The B cell follicle infiltrative pattern was associated with prolonged recurrence free survival. Conclusion: These data suggest a role for B cell follicles in coordinating effective adaptive immune responses in melanoma when low volume metastatic disease is present in tumor draining LN.

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.

Identification of a Germline Pyrin Variant in a Metastatic Melanoma Patient With Multiple Spontaneous Regressions and Immune-related Adverse Events.

The mechanisms underlying tumor immunosurveillance and their association with the immune-related adverse events (irAEs) associated with checkpoint inhibitor immunotherapies remain poorly understood. We describe a metastatic melanoma patient exhibiting multiple episodes of spontaneous disease regression followed by the development of several irAEs during the course of anti-programmed cell death protein 1 antibody immunotherapy. Whole-exome next-generation sequencing studies revealed this patient to harbor a pyrin inflammasome variant previously described to be associated with an atypical presentation of familial Mediterranean fever. This work highlights a potential role for inflammasomes in the regulation of tumor immunosurveillance and the pathogenesis of irAEs.

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.

An Atypical Myelomonocytic Cell Infiltrate: Use of Next-Generation Sequencing to Diagnose Indeterminate Cell Histiocytosis.

ABSTRACT: Indeterminant cell histiocytosis (ICH) is a rare lymphoproliferative disorder that demonstrates features of Langerhans and non-Langerhans cell histiocytoses and diagnosis can be challenging. We present a case of a 62 year old woman with a generalized eruption of erythematous papules on the face, trunk and extremities. Skin biopsies demonstrated a dermal mononuclear cell infiltrate with monocytic (CD4, CD33), histiocytic (CD68, CD163), and dendritic cell (CD1a) immunophenotype but negative for Langerhans' cell marker (CD207). The differential diagnosis included leukemia cutis and ICH, and further workup revealed a normal bone marrow biopsy. To confirm the diagnosis of ICH, next generation sequencing with ETV3-NCOA2 gene fusion was performed and was positive. The patient's condition improved with methotrexate and narrow band UVB phototherapy. Our case adds to the existing literature supporting the use of next-generation sequencing to test for ETV3-NCOA2 gene fusion in suspected cases of ICH.