Sartori-Valinotti, Julio C.

Introduction: Limited research explores dermoscopy use among physician associates (PAs), outside of one prior study examining dermoscopy in PA student education. This study sought to investigate dermoscopy use among practicing PAs and its impact on their overall diagnostic confidence, including in darker skin tones, when differentiating between benign and malignant skin lesions. Methods: An anonymous survey was developed in 2023 with input from experts in dermoscopy and survey creation to assess PA confidence in skin lesion evaluation as well as PA dermoscopy knowledge and use, perceptions, barriers to use, and prior education. The dermoscopy survey was included as an optional module in the 2024 American Academy of Physician Associates (AAPA) Salary Survey. Results: Of 3,174 invited PAs, 995 (31.4%) responded. Most had never used dermoscopy in practice (81%) but knew or recognized the term (71%). A majority (53%) believed PAs should be trained in dermoscopy during PA school, and 26% reported no interest in future dermoscopy use. Dermatology PAs reported more frequent dermoscopy use and generally greater confidence in evaluating skin lesions, both overall and in darker skin tones, than PAs in other specialties. PAs in surgical (OR=0.2, 95% CI 0.1-0.6) and medical (OR=0.3, 95% CI 0.2-0.5) subspecialties were less likely to use dermoscopy at least annually compared with PAs in primary care. PAs in rural areas were more likely to feel confident in differentiating skin lesions than those in urban areas (OR 2.9, 95% CI 1.7-5.0). Conclusion: Dermoscopy use is associated with higher overall skin lesion assessment confidence. Wider adoption, especially outside dermatology, requires training, increased advocacy, and expanded education.

PURPOSE BRAF and MEK inhibitors are standard treatments in histiocytic disorders, such as Erdheim-Chester disease (ECD). Some patients lack MAPK-pathway alterations, making these treatments less effective. METHODS We describe three patients with histiocytic disorders who have novel non-MAPK pathway alterations. These alterations were studied through genomic and in silico analyses when applicable, then treated with off-label medications rationally selected on the basis of genomic alterations. RESULTS Patient 1 had rapidly progressive ECD involving the CNS. A CSF1R in-frame deletion (p.S560_P566del) was identified, and in silico modeling predicted a gain-of-function mutation. This alteration was targeted with pexidartinib, which led to a clinical complete response (CR) within 2 months, and a partial response (PR) on imaging after 3 months. After 15 months, the disease became resistant to pexidartinib and transformed to histiocytic sarcoma. Patient 2 has skin-only involvement of a xanthogranuloma disorder. A KIF5B-FGFR1 fusion was identified on RNA sequencing and targeted with pemigatinib. At 24 months of follow-up, she remains in a clinical PR. Patient 3 has ECD involving the bone marrow, gastrointestinal tract, and subcutaneous tissues. A MEF2C-FLT3 fusion was identified and targeted with sorafenib. He achieved a clinical CR and radiographic PR within 3 months, which has continued for 30 months. CONCLUSION We report three patients with histiocytic disorders harboring novel alterations who had sustained responses to off-label kinase inhibitors specific to their histiocytic disorder. Pathogenic variants outside of the MAPK pathway, including variants of unknown significant, may be targeted with readily available small molecules.

AbstractBackgroundVEXAS (vacuoles, E1 enzyme, X‐linked, autoinflammatory, somatic) syndrome is an autoinflammatory disease with frequent cutaneous manifestations.MethodsWe conducted a retrospective study of all patients with genetically confirmed VEXAS syndrome seen at our institution. Available clinical photographs and skin biopsy slides were reviewed.ResultsCutaneous manifestations developed in 22/25 (88%) patients with VEXAS syndrome. From this group, 10/22 (45%) developed skin involvement before or at the time of other clinical features of VEXAS. Twenty distinct dermatologic presentations of VEXAS from 14 patients were reviewed, and histopathologic patterns were classified as follows: neutrophilic urticarial dermatosis (n = 5, 25%), leukocytoclastic/urticarial vasculitis (n = 4, 20%), urticarial tissue reaction (n = 4, 20%), neutrophilic dermatosis (n = 3, 15%), neutrophilic panniculitis (n = 2, 10%), and nonspecific chronic septal panniculitis (n = 2, 10%). Common systemic findings included macrocytic anemia (96%), fever (88%), thrombocytopenia (76%), weight loss (76%), ocular inflammation (64%), pulmonary infiltrates (56%), deep venous thrombosis or pulmonary embolism (52%), and inflammatory arthritis (52%).ConclusionsCutaneous involvement is a common feature of VEXAS syndrome, and histopathologic findings exist on a spectrum of neutrophilic inflammatory dermatoses.

Abstract Introduction Histiocytic disorders pose significant diagnostic and management challenges for the clinicians due to diverse clinical manifestations and often non-specific histopathologic findings. Herein, we report the tumor board experience from the first-of-its-kind Histiocytosis Working Group (HWG). Materials and Methods The HWG was established in June 2017 and consists of experts from 10 subspecialties that discuss cases in a multidisciplinary format. We present the outcome of tumor board case discussions during the first 2 years since its inception (June 2017-June 2019). Results Forty cases with a suspected histiocytic disorder were reviewed at HWG during this time period. Average number of subspecialties involved in HWG case discussion was 5 (range, 2-9). Histiocytosis Working Group tumor board recommendations led to significant changes in the care of 24 (60%) patients. These included change in diagnosis (n = 11, 27%) and change in treatment (n = 13, 33%). Conclusion Our report highlights the feasibility of a multidisciplinary tumor board and its impact on outcomes of patients with histiocytic disorders.

Introduction Dermatologic complaints are a common reason for emergency department visits. Methods Retrospective chart review from 1 January 2015 to 31 December 2019. Patients in the Mayo Clinic Emergency Department receiving dermatology consultation were included. Results Dermatitis (24.7%, n = 113), infection (20.4%, n = 93), and drug reaction (10.3%, n = 47) accounted for the majority of diagnoses. Emergency department providers often provide no diagnosis (38%) or a differential diagnosis (22%), and dermatology consultation frequently alters diagnosis (46%) and treatment (83%). Patients receiving in-person consultations are admitted more frequently than those receiving teledermatology consultations (40% vs. 16%, p < 0.001). Primary diagnostic concordance with subsequent dermatology evaluation is high for in-person (94%) and teledermatology (88%) consultations. Discussion This is the largest study of emergency department dermatology consultations in the United States and the first to compare in-person and teledermatology emergency department consultation utilization in clinical practice. These modalities are utilized in a complementary fashion at our institution, with severe dermatologic diagnoses seen in-person. The valuable role of emergency department dermatologists is highlighted by frequent changes to diagnosis and treatment plans that result from dermatology consultation. Furthermore, our data suggest that teledermatology is an effective modality with the potential to expand access to dermatologic expertise in the emergency department setting.

AbstractBackgroundHospitalized patients with hematologic malignancies are medically complex and commonly affected by dermatologic conditions.MethodsRetrospective chart review from January 1, 2014, to December 31, 2018, at Rochester Methodist Hospital (Rochester, Minnesota, USA). Patients hospitalized on hematology and BMT services receiving dermatology consultation were included.ResultsIn all, 578 consultations (63% male, median age 61 years) were reviewed. Drug reactions (22%), infection (17%), and malignant neoplasm (10%) accounted for nearly half of diagnoses. Exanthematous drug reaction (10%), graft‐versus‐host disease (7%), and lymphoma or leukemia cutis (6%) were the commonest individual diagnoses. There were significantly more drug reactions in severe neutropenia (33.2% vs. 15.0%), neutrophilic dermatoses in myeloid neoplasm (5.2% vs. 0.3%), and viral infection in lymphoid neoplasm (8.3% vs. 1.2%). Consultation frequently altered treatment (68%), diagnostic workup (63%), and the primary service’s initial diagnostic impression (53%). Biopsies were performed in 52% of consultations and helped secure a diagnosis 73% of the time. A total of 16.4% of consultations did not receive a definitive final diagnosis, and 18.5% were resolved in one visit.ConclusionThis is the largest study to date of hospital dermatology consultation in hematology patients. Biopsies are utilized frequently and are diagnostically useful. The complexity of this patient population is evidenced by the fact that a final diagnosis remains elusive in a number of cases despite the multiple visits required for the vast majority of consultations. Nevertheless, dermatology consultation alters diagnosis and treatment in the majority of patients, highlighting the critical role dermatologists have in the care of these patients.

AbstractBackgroundAngioimmunoblastic T‐cell lymphoma (AITL) is a systemic peripheral T‐cell lymphoma with a follicular helper T‐cell (TFH) immunophenotype that frequently involves the skin. However, the histopathology of cutaneous involvement by AITL has not been fully established.MethodsWe reviewed the clinicopathological features of 19 patients seen at our institution with AITL involving the skin. Pan‐T‐cell and TFH marker expression was evaluated by immunohistochemistry. Epstein‐Barr virus (EBV) was detected using in situ hybridization (ISH) for Epstein‐Barr virus‐encoded small RNA (EBER). T‐cell receptor (TCR) gene rearrangement was evaluated by PCR.ResultsAITL affected both trunk and extremities in 15/19 cases (79%). Perivascular infiltration by small and/or medium‐sized lymphocytes was seen in 18/19 (95%). Granulomatous inflammation was identified in 4/19 (21%). Aberrant loss of CD2, CD5, or CD7 was identified in 1/18 (6%), 2/18 (11%), or 7/19 (37%) cases, respectively. Seventeen of eighteen evaluable cases (95%) expressed 2 to 3 TFH markers: PD‐1 in 19/19 (100%), BCL6 in 94% (17/18), and CD10 in 37% (7/19). EBV‐positive cells were detected in 3/18 (17%) with varying density. Clonal TCR gene rearrangement was identified in 9/11 (82%).ConclusionsCutaneous involvement by AITL shows relatively non‐specific histopathological features. However, an immunohistochemical panel including TFH markers and EBER ISH is useful in differential diagnosis.