Citations

ABSTRACT Primary cutaneous NUT adnexal carcinoma is an emerging provisional tumor entity characterized by NUTM1 rearrangement with fusion partners different from poroid neoplasms. These tumors should be distinguished from NUT carcinomas with a histopathologic appearance of poorly differentiated squamous cell carcinoma, which tend to behave more aggressively and demonstrate a widespread anatomic distribution. Since fewer than 20 cases of NUT adnexal carcinoma have been reported in the literature, we report herein another case to enhance our knowledge of the spectrum of clinical and pathologic features associated with this tumor. This case is characterized by an unusual clinical course. The lesion was present and slowly progressed over the course of 13 years prior to biopsy and excision. The tumor was composed of epithelial and myoepithelial elements with a range of features, including ductal, cribriform, and solid, with papillary, secretory, and keratocystic changes. The patient underwent wide local excision and sentinel lymph node biopsy, which revealed metastatic tumor. Molecular testing identified a BRD3‐NUTM1 fusion, confirming the diagnosis of NUT adnexal carcinoma. The patient remains disease‐free at 1‐year follow‐up without further therapy.

ImportanceDirect immunofluorescence (DIF) testing has been an important ancillary tool for the diagnosis of various inflammatory mucocutaneous conditions for more than 50 years. Current DIF test panels are based on historical clinical descriptions; few studies have rigorously addressed preanalytical, analytical, and/or postanalytical aspects, and even fewer have been replicated or validated. Recent unresolved key issues include whether DIF testing and test panels should be triaged or truncated based on clinical indication or histopathologic findings.ObjectiveTo assess levels of consensus regarding practical aspects of DIF testing among immunodermatology testing specialists in the US.Design, Setting, and ParticipantsUsing modified Delphi methods with a priori characterized criteria, a survey containing 54 statements pertaining to DIF testing was created and distributed to assess consensus. Statements not initially reaching consensus were discussed in 2 live virtual sessions, which were supplemented by relevant literature review and free-text survey comments. These statements were then reassessed in a second survey. Immunodermatology testing specialists in US academic institution–based and independent laboratories were invited based on serving as immunodermatology laboratory medical directors, authoring pertinent literature, or delivering relevant talks at major conferences or by referral. The first survey was conducted from January to February 2024, and the second survey was conducted from March to April 2024.Main Outcomes and MeasuresThe primary measured outcome was degree of consensus for various DIF testing practice, including DIF testing triage by histopathology/dermatopathology findings and DIF testing panel tailored truncations by clinical indication.ResultsA total of 23 respondents to the survey invitation had a mean (SD) of 18.5 (11.1) years and median (range) of 20.0 (1.5-46.0) years in immunodermatology laboratory practice. Consensus was achieved for 46 of 54 statements (85.2%) in the initial survey and for an additional 4 statements in the second survey (50 of 54 [92.6%]). Strong consensus was found against tailored truncation of DIF panel based on the clinical indication in the first survey round. The general acceptability of triaging specimens for DIF testing based on histopathology findings remained without consensus after both surveys.Conclusions and RelevanceOverall, participating US specialists in immunodermatology laboratory testing agreed on many practical aspects of DIF testing, including matters not queried previously. The findings also revealed areas of continued controversy and identified issues for prioritized future study.

AbstractChimeric antigen receptor (CAR) T‐cell therapy has demonstrated remarkable success in treating various B‐cell malignancies, redirecting T‐cell cytotoxicity toward cancer cells. Despite its efficacy, CAR‐T therapy is associated with potential risks, including cytokine release syndrome (CRS) and cytopenia. We present a case of a 69‐year‐old man with diffuse large B‐cell lymphoma treated with axicabtagene‐ciloleucel CAR‐T therapy, who developed a rare and severe cutaneous toxicity resembling toxic epidermal necrolysis (TEN). The patient exhibited persistent fevers, CRS, and subsequent development of a widespread erythematous macular eruption, progressing to vesiculation with bullae. Notably, allopurinol‐induced TEN was considered with the patient's recent exposure to allopurinol, although the onset and minimal mucosal involvement did not align with typical presentations of allopurinol‐induced cases. The cutaneous reaction, distinct from typical SJS/TEN, showed minimal mucosal involvement and coincided with the cytokine release storm, differing from allopurinol‐induced TEN. Despite the absence of guidelines, the patient was managed with systemic steroids, achieving significant improvement. This case expands the spectrum of CAR‐T therapy‐related cutaneous toxicities, highlighting the need for early recognition of histopathology and tailored management by dermatologists. Further understanding of these reactions is crucial for optimizing the safety profile of this groundbreaking immunotherapy.

Importance Scoring systems for Stevens-Johnson syndrome and epidermal necrolysis (EN) only estimate patient prognosis and are weighted toward comorbidities and systemic features; morphologic terminology for EN lesions is inconsistent. Objectives To establish consensus among expert dermatologists on EN terminology, morphologic progression, and most-affected sites, and to build a framework for developing a skin-directed scoring system for EN. Evidence Review A Delphi consensus using the RAND/UCLA appropriateness criteria was initiated with a core group from the Society of Dermatology Hospitalists to establish agreement on the optimal design for an EN cutaneous scoring instrument, terminology, morphologic traits, and sites of involvement. Findings In round 1, the 54 participating dermatology hospitalists reached consensus on all 49 statements (30 appropriate, 3 inappropriate, 16 uncertain). In round 2, they agreed on another 15 statements (8 appropriate, 7 uncertain). There was consistent agreement on the need for a skin-specific instrument; on the most-often affected skin sites (head and neck, chest, upper back, ocular mucosa, oral mucosa); and that blanching erythema, dusky erythema, targetoid erythema, vesicles/bullae, desquamation, and erosions comprise the morphologic traits of EN and can be consistently differentiated. Conclusions and Relevance This consensus exercise confirmed the need for an EN skin-directed scoring system, nomenclature, and differentiation of specific morphologic traits, and identified the sites most affected. It also established a baseline consensus for a standardized EN instrument with consistent terminology.

AbstractBackgroundAppropriate 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.MethodsRAND/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.ResultsFor 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.ConclusionsAUC 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.