Sokumbi, Olayemi

ABSTRACT We report a case of a 71‐year‐old female with acute myeloid leukemia (AML), treated with chemotherapy and hematopoietic stem cell transplant (HSCT), who developed a clonally related non‐Langerhans cell histiocytosis (NLCH). She presented with pink papules on the mid‐upper cutaneous lip and thighs 3 months following HSCT. Skin biopsies revealed a dermal proliferation of cells with eosinophilic cytoplasm. Immunohistochemistry (IHC) studies demonstrated positivity for CD68, CD163, BRAF, cyclin D1, and Factor XIIIa and negativity for CD1a, S100, MPO, and CD20. Next‐generation sequencing (NGS) with a comprehensive myeloid panel revealed corresponding pathogenic mutations to her AML, including BCOR Q176fs*40, IDH1 R132C, and TP53 Y163N, and an additional BRAF V600E mutation. Additional mutations in DNMT3A and KMT2A associated with her AML were not identified. These findings supported the diagnosis of NLCH sharing a clonal origin with the patient's AML. Work up demonstrated isolated cutaneous involvement without AML relapse; therefore, the skin lesions were treated with shave excision, topical tacrolimus 0.1% ointment, and topical clobetasol 0.05% cream without further systemic treatment. The acquired BRAF V600E mutation illustrates the potential for divergent myeloid differentiation and likely explains the emergence of a clonal NLCH after successful AML treatment. Genetic analysis in NLCH can establish clonality with associated hematologic malignancies, uncover actionable mutations, and guide treatment.

ABSTRACT Part I of our three‐part series outlines the essential technical and operational components required for successful digital pathology implementation including hardware, software, and IT infrastructure. It reviews the rationale for digitization, highlighting improvements in workflow efficiency, diagnostic collaboration, and preparedness for computational applications. Key components of Whole Slide Imaging (WSI) systems are discussed, including practical considerations for scanner selection, scanning modalities, and performance trade‐offs relevant to dermatopathology. The article also examines image compression strategies and pyramid image representation, with attention to balancing image quality and storage efficiency. Finally, we review DICOM standards and storage infrastructure options, including cloud, on‐premises, and hybrid models, and associated network bandwidth requirements.

Dermatofibrosarcoma protuberans (DFSP) is a rare slow-growing skin cancer with a great capacity for local destruction. DFSP can manifest in a myriad of ways. This case report aims to contribute to the literature by increasing awareness of this condition, along with common diagnostic practices and treatment regimens. We present a 52-year-old Filipino woman who was evaluated for dyspnea with an incidental finding of an indeterminate nodule on imaging. A comprehensive diagnostic workup confirmed dermatofibrosarcoma protuberans (DFSP), which was ultimately treated with surgical resection. Clinically, about 52% of patients are misdiagnosed, leading to poor outcomes. Therefore, awareness, early detection, multidisciplinary treatment, and lifelong screening are essential for optimal outcomes.

ABSTRACTBackgroundThere is a known association between common variable immunodeficiency (CVID) and granulomas in multiple organ systems, including the skin, lung, liver, and spleen. Rubella virus has also been detected within cutaneous granulomas in both immunocompetent and immunocompromised hosts. We present a retrospective case series of patients with CVID and granulomatous skin disease and describe the spectrum of clinical and histopathologic features, including the status of rubella virus in the cutaneous granulomas.MethodsWe retrospectively reviewed the clinical and histopathological characteristics of patients diagnosed with CVID at our institution, with cutaneous findings and skin biopsies available for review between 1990 and 2023, demonstrating granulomatous inflammation.ResultsEight patients met the inclusion criteria. The most common histopathologic pattern was palisaded granulomatous inflammation, seen in five of eight cases. Three cases showed strictly sarcoidal granulomas. Background inflammation was peri‐granulomatous (8/8) and the predominant background inflammatory cell type was lymphocytic (6/8). Rubella virus testing was performed for seven of eight cases and found to be positive in one case.ConclusionCutaneous granulomatous disease in CVID can present with a spectrum of clinical morphologies, granulomatous patterns, and variable rubella virus persistence. Dermatopathologists should be aware of the spectrum of findings when considering cutaneous CVID–related granulomatous disease in the differential diagnosis.

AbstractHistiocytoid Sweet syndrome (H‐SS) is a histopathological variant of Sweet syndrome (SS) defined by cutaneous infiltration of immature myeloid cells morphologically resembling histiocytes. The association of H‐SS with underlying malignancy, particularly myelodysplastic syndromes, is well‐established. Myelodysplasia cutis (MDS‐cutis) has been proposed to describe cases historically diagnosed as H‐SS but characterized by shared clonality of the myeloid infiltrate in skin and bone marrow. Therefore, identifying patients who might have MDS‐cutis is critical for the management of the associated hematologic malignancy. VEXAS syndrome, an adult‐onset autoinflammatory disease, should also be included in the histopathologic differential diagnosis of H‐SS, as it shares clinical and pathologic features with MDS‐cutis. Through the presentation of two cases, we aim to highlight the defining features and key clinical implications of MDS‐cutis and VEXAS syndrome.

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.

AbstractAn 11‐year‐old female was referred from an outside institution after a diagnostic biopsy and subsequent excision of a progressively enlarging reddish‐brown nodule demonstrated features concerning for a balloon cell nevus with severe atypia versus a high‐grade melanocytoma. Upon review of the initial biopsy specimen and molecular data, we favored the diagnosis to be consistent with a high‐grade melanocytoma with balloon cell changes while considering the possibility of balloon cell melanoma due to concerning histopathologic and genetic abnormalities. In this case study, we discuss critical diagnostic considerations in this rare pediatric case and highlight important pathologic and clinical features of melanocytomas and balloon cell melanoma.

AbstractBackgroundTechnology has revolutionized not only direct patient care but also diagnostic care processes. This study evaluates the transition from glass‐slide microscopy to digital pathology (DP) at a multisite academic institution, using mixed methods to understand user perceptions of digitization and key productivity metrics of practice change.MethodsParticipants included dermatopathologists, pathology reporting specialists, and clinicians. Electronic surveys and individual or group interviews included questions related to technology comfort, trust in DP, and rationale for DP adoption. Case volumes and turnaround times were abstracted from the electronic health record from Qtr 4 2020 to Qtr 1 2023 (inclusive). Data were analyzed descriptively, while interviews were analyzed using methods of content analysis.ResultsThirty‐four staff completed surveys and 22 participated in an interview. Case volumes and diagnostic turnaround time did not differ across the institution during or after implementation timelines (p = 0.084; p = 0.133, respectively). 82.5% (28/34) of staff agreed that DP improved the sign‐out experience, with accessibility, ergonomics, and annotation features described as key factors. Clinicians reported positive perspectives of DP impact on patient safety and interdisciplinary collaboration.ConclusionsOur study demonstrates that DP has a high acceptance rate, does not adversely impact productivity, and may improve patient safety and care collaboration.