Ryanne Brown, MD

View details for Web of Science ID 000629690900270

View details for Web of Science ID 000629690900847

View details for DOI 10.1111/cup.13971

View details for PubMedID 33495995

View details for DOI 10.1111/cup.13963

View details for PubMedID 33458834

Abstract

Alloimmune responses in acute rejection are complex, involving multiple interacting cell types and pathways. Deep profiling of these cell types has been limited by technology that lacks the capacity to resolve this high dimensionality. Single-cell mass cytometry is used to characterize the alloimmune response in early acute rejection, measuring 37 parameters simultaneously, across multiple time points in two models: a murine cardiac and vascularized composite allotransplant (VCA). Semi-supervised hierarchical clustering is used to group related cell types defined by combinatorial expression of surface and intracellular proteins, along with markers of effector function and activation. This expression profile is mapped to visualize changes in antigen composition across cell types, revealing phenotypic signatures in alloimmune Tcells, natural killer (NK) cells, and myeloid subsets that are conserved and that firmly distinguish rejecting from non-rejecting grafts. These data provide a comprehensive, high-dimensional profile of cellular rejection after allograft transplantation.

View details for DOI 10.1016/j.celrep.2021.108806

View details for PubMedID 33657374

Abstract

Atypical fibroxanthoma (AFX) is a neoplasm that most commonly occurs on sun-damaged skin of the head and neck in elderly patients and that usually exhibits indolent clinical behavior with complete excision. The granular cell variant of AFX demonstrates overlapping histopathologic features with dermal non-neural granular cell tumor (NNGCT), which typically arises on the extremities of young to middle aged adults with rare reports of regional metastasis. A subset of NNGCT harbors ALK rearrangements and expresses ALK by immunohistochemistry. Here, we present 2 cases of granular cell AFX occurring on the scalp of males aged 73 and 87 with ALK expression by immunohistochemistry and no evidence of an ALK rearrangement on fluorescence in situ hybridization, representing a diagnostic pitfall for NNGCT.

View details for DOI 10.1097/DAD.0000000000001931

View details for PubMedID 33767072

View details for Web of Science ID 000600556200003

View details for DOI 10.1016/j.jdcr.2020.05.032

View details for PubMedID 33134460

View details for DOI 10.1111/cup.13890

View details for PubMedID 33034114

Abstract

BACKGROUND: Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of extranodal non-Hodgkin lymphomas for which diagnosis can be challenging given the potential for overlap with inflammatory dermatoses. Current diagnostic criteria for CTCL incorporate clinical and histopathologic findings as well as results of T-cell receptor (TCR) gene sequencing. Molecular interrogation of TCR genes, TRG and TRB, has provento be a critical tool for confirming diagnoses of CTCL and for disease tracking after initiation of therapy or after stem cell transplant. Methods for confirming a diagnosis of lymphoma in the absence of TCR gene clonality are lacking. We present two patients with CTCL with pathogenic somatic mutations in the absence of TRG and TRB clonality.CASE PRESENTATIONS: Case 1: A 38-year-old male had a 19-year history of a diffuse skin rash with papulosquamous, granulomatous, and verrucous features and progressive ulcerated plaques and tumors demonstrating an atypical CD4+ T-cell infiltrate with expression of cytotoxic markers CD56, TIA-1, granzyme, and perforin on histopathology. No definitive evidence for T-cell clonality was detected by conventional PCR of 6 biopsies or by next-generation sequencing (NGS) of 14 biopsies. Somatic mutational profiling of a skin biopsy revealed pathogenic mutations in PIKC3D and TERT promoter hotspots, confirming the presence of a clonal process. Case 2: A 69-year-old male with a 13-year history of progressive, diffuse hypertrophic and eroded plaques showed an atypical CD4+ T-cell infiltrate with subset expression of TIA-1 and granzyme on histopathology. No TCR clonality was detected by TCR-NGS of 6 biopsies. Somatic mutational profiling of a skin biopsy detected a pathogenic mutation in TP53, confirming the presence of a clonal process.CONCLUSIONS: These cases highlight how detection of pathogenic somatic mutations can confirma diagnosis of lymphoma in a clinically and histopathologically suspicious cutaneous lymphoid proliferation without detectable TCR clonality.

View details for DOI 10.1186/s13000-020-01022-x

View details for PubMedID 32988392

Abstract

Scleroderma is a devastating fibrotic autoimmune disease. Current treatments are partly effective in preventing disease progression but do not remove fibrotic tissue. Here, we evaluated whether scleroderma fibroblasts take advantage of the "don't-eat-me-signal" CD47 and whether blocking CD47 enables the body's immune system to get rid of diseased fibroblasts. To test this approach, we used a Jun-inducible scleroderma model. We first demonstrated in patient samples that scleroderma upregulated transcription factor JUN and increased promoter accessibilities of both JUN and CD47. Next, we established our scleroderma model, demonstrating that Jun mediated skin fibrosis through the hedgehog-dependent expansion of CD26+Sca1- fibroblasts in mice. In a niche-independent adaptive transfer model, JUN steered graft survival and conferred increased self-renewal to fibroblasts. In vivo, JUN enhanced the expression of CD47, and inhibiting CD47 eliminated an ectopic fibroblast graft and increased in vitro phagocytosis. In the syngeneic mouse, depleting macrophages ameliorated skin fibrosis. Therapeutically, combined CD47 and IL-6 blockade reversed skin fibrosis in mice and led to the rapid elimination of ectopically transplanted scleroderma cells. Altogether, our study demonstrates the efficiency of combining different immunotherapies in treating scleroderma and provides a rationale for combining CD47 and IL-6 inhibition in clinical trials.

View details for DOI 10.1172/jci.insight.140458

View details for PubMedID 32814713

Abstract

BACKGROUND: PRAME (PReferentially expressed Antigen in MElanoma) has shown utility in distinguishing melanoma from benign melanocytic lesions, but knowledge of its expression pattern in intermediate melanocytic and spitzoid proliferations is limited.METHODS: Immunohistochemical expression of PRAME was examined in 112 melanocytic proliferations with intermediate histopathologic or spitzoid features.RESULTS: Any intensity of PRAME staining in at least 60% of lesional melanocytes was determined as the best threshold for diffuse staining in this cohort. Nearly all non-spitzoid melanomas (23/24; 95.8%) demonstrated diffuse PRAME expression. PRAME was completely negative in 95.6% (43/45) of mitotically-active nevi, traumatized nevi, nevi with persistent/recurrent features, and dysplastic nevi. Most Spitz nevi (15/20) and atypical Spitz tumors (10/13) entirely lacked PRAME expression. One Spitz nevus, one atypical Spitz tumor, and one case of spitzoid melanoma (1/2) demonstrated diffuse PRAME expression.CONCLUSIONS: Although diffuse PRAME expression is generally limited to malignant melanoma, benign Spitz nevi and atypical Spitz tumors can infrequently express diffuse PRAME. PRAME immunohistochemistry can be useful in the evaluation of atypical melanocytic proliferations with intermediate histopathologic features but should be interpreted with caution in the setting of spitzoid neoplasms. This article is protected by copyright. All rights reserved.

View details for DOI 10.1111/cup.13818

View details for PubMedID 32700786

Abstract

Deep penetrating nevi (DPNs) are intermediate grade lesions which have the capacity to recur, metastasize, or progress to melanoma. Differentiating DPN from other melanocytic lesions including blue and cellular blue nevi can be diagnostically challenging, and markers to distinguish these entities can be useful. Mutations of the beta-catenin and mitogen-activated protein kinase pathways have recently been elucidated as distinctive of DPN. This pathway can subsequently activate lymphoid enhancer-binding factor 1 (LEF1), a transcription factor shown to facilitate the epithelial-mesenchymal transition to propagate tumorigenesis. Seventy-two cases in total were examined on hematoxylin and eosin sections and with beta-catenin and LEF1 immunohistochemistry. This included: DPN (14), cellular blue nevi (19), blue nevi (15), congenital melanocytic nevi (12), and melanoma (12). Nuclear expression of LEF1, present throughout the entire depth of the lesion, was noted in 13/14 (93%) of DPN, 0/19 (0%) of cellular blue nevi, 0/15 (0%) of blue nevi, 1/12 (8%) of congenital melanocytic nevi, and 9/12 (75%) of melanoma cases. Nuclear expression of beta-catenin, present throughout the entire depth of the lesion, was noted in 14/14 (100%) of DPN, 0/18 (0%) of cellular blue nevi, 0/15 (0%) of blue nevi, 1/12 (8%) of congenital melanocytic nevi, and 1/12 (8%) of melanoma cases. A majority of congenital melanocytic nevi demonstrated a gradient of LEF1 and beta-catenin expression with more intense staining superficially and loss of staining with increasing depth. Deep, uniform nuclear LEF1 combined with beta-catenin immunohistochemical staining can be useful in distinguishing DPN from histologic mimics.

View details for DOI 10.1097/PAS.0000000000001513

View details for PubMedID 32520758

Abstract

Primary cutaneous signet-ring cell/histiocytoid carcinoma of the eyelid is a rare and aggressive neoplasm. Fewer than 50 cases have been reported in the literature, and the genetic driving mutations are unknown. Herein, we present a case of this rare disease along with the results of molecular profiling via targeted next generation sequencing. The patient is an 85-year-old man who presented with left eyelid swelling initially thought to be a chalazion. After no response to incision and drainage and antibiotics, an incisional biopsy was performed. Histologic sections revealed a proliferation of cells with signet-ring and histiocytoid morphology arranged singly and in cords infiltrating the dermis, subcutaneous tissue, and muscle. The lesional cells strongly expressed cytoplasmic cytokeratin 7 and nuclear androgen receptor. Next generation sequencing revealed a CDH1 mutation, which is known to confer signet-ring morphology in other carcinomas. Pathogenic mutations in NTRK3, CDKN1B and PIK3CA were also detected. To our knowledge, this is the first documented genetic analysis of this rare disease with findings that offer insights into disease pathogenesis and potential therapeutic targets. This article is protected by copyright. All rights reserved.

View details for DOI 10.1111/cup.13733

View details for PubMedID 32358805

Abstract

Pleomorphic fibromas are rare benign cutaneous neoplasms associated with deletion/loss of chromosomes 13q and 17p, where RB1 and TP53 are located, respectively. Herein, we report five cases of pleomorphic fibroma arising in patients with germline TP53 mutations, suggesting a potential link with Li-Fraumeni syndrome. All three patients were female and young (mean age 27) with a strong personal and/or family oncologic history and confirmed pathogenic germline TP53 mutations. In two patients, multiple pleomorphic fibromas were diagnosed. Clinically, the lesions arose at various cutaneous sites and were small (2cm) and raised (4/5). Histologically, the tumors were paucicellular, comprised of atypical spindled to stellate cells with hyperchromatic and variably pleomorphic nuclei. Mitotic activity was exceedingly low, although rare atypical mitotic figures were seen in one case. Immunohistochemically, the tumor cells were diffusely positive for p16 (3/3) and showed loss of Rb expression (5/5). All cases showed aberrant p53 expression (overexpression in 4, complete loss in 1). The tumors have followed a benign clinical course with no evidence of progression or recurrence. In conclusion, the development of multiple pleomorphic fibromas in a young patient may be a clue to an underlying genetic cancer syndrome involving TP53. This article is protected by copyright. All rights reserved.

View details for DOI 10.1111/cup.13686

View details for PubMedID 32187703

Abstract

Cutaneous tuberculosis is an uncommon entity with several clinical forms recognized. Histopathologically, most cases are characterized by granulomatous inflammation and caseating necrosis, though less common findings, including vasculitis, have also been described. We report a 55-year-old male with a history of recently diagnosed dermatomyositis receiving immunosuppression with mycophenolate mofetil and prednisone, who developed multifocal soft tissue abscesses and an indurated erythematous plaque on the back. Skin biopsy of the back revealed a necrotizing medium-vessel vasculitis. M. tuberculosis was detected in the skin via acid-fast bacilli stain and confirmed by tissue culture and polymerase chain reaction. Cutaneous findings improved rapidly with anti-tuberculosis therapy. This case illustrates an uncommon clinical and histopathologic presentation of disseminated tuberculosis. This article is protected by copyright. All rights reserved.

View details for DOI 10.1111/cup.13678

View details for PubMedID 32133689

Abstract

Artificial intelligence (AI) algorithms continue to rival human performance on a variety of clinical tasks, while their actual impact on human diagnosticians, when incorporated into clinical workflows, remains relatively unexplored. In this study, we developed a deep learning-based assistant to help pathologists differentiate between two subtypes of primary liver cancer, hepatocellular carcinoma and cholangiocarcinoma, on hematoxylin and eosin-stained whole-slide images (WSI), and evaluated its effect on the diagnostic performance of 11 pathologists with varying levels of expertise. Our model achieved accuracies of 0.885 on a validation set of 26 WSI, and 0.842 on an independent test set of 80 WSI. Although use of the assistant did not change the mean accuracy of the 11 pathologists (p=0.184, OR=1.281), it significantly improved the accuracy (p=0.045, OR=1.499) of a subset of nine pathologists who fell within well-defined experience levels (GI subspecialists, non-GI subspecialists, and trainees). In the assisted state, model accuracy significantly impacted the diagnostic decisions of all 11 pathologists. As expected, when the model's prediction was correct, assistance significantly improved accuracy (p=0.000, OR=4.289), whereas when the model's prediction was incorrect, assistance significantly decreased accuracy (p=0.000, OR=0.253), with both effects holding across all pathologist experience levels and case difficulty levels. Our results highlight the challenges of translating AI models into the clinical setting, and emphasize the importance of taking into account potential unintended negative consequences of model assistance when designing and testing medical AI-assistance tools.

View details for DOI 10.1038/s41746-020-0232-8

View details for PubMedID 32140566

View details for PubMedCentralID PMC7044422

Abstract

Artificial intelligence (AI) algorithms continue to rival human performance on a variety of clinical tasks, while their actual impact on human diagnosticians, when incorporated into clinical workflows, remains relatively unexplored. In this study, we developed a deep learning-based assistant to help pathologists differentiate between two subtypes of primary liver cancer, hepatocellular carcinoma and cholangiocarcinoma, on hematoxylin and eosin-stained whole-slide images (WSI), and evaluated its effect on the diagnostic performance of 11 pathologists with varying levels of expertise. Our model achieved accuracies of 0.885 on a validation set of 26 WSI, and 0.842 on an independent test set of 80 WSI. Although use of the assistant did not change the mean accuracy of the 11 pathologists (p=0.184, OR=1.281), it significantly improved the accuracy (p=0.045, OR=1.499) of a subset of nine pathologists who fell within well-defined experience levels (GI subspecialists, non-GI subspecialists, and trainees). In the assisted state, model accuracy significantly impacted the diagnostic decisions of all 11 pathologists. As expected, when the model's prediction was correct, assistance significantly improved accuracy (p=0.000, OR=4.289), whereas when the model's prediction was incorrect, assistance significantly decreased accuracy (p=0.000, OR=0.253), with both effects holding across all pathologist experience levels and case difficulty levels. Our results highlight the challenges of translating AI models into the clinical setting, and emphasize the importance of taking into account potential unintended negative consequences of model assistance when designing and testing medical AI-assistance tools.

View details for DOI 10.1038/s41746-020-0232-8

View details for PubMedID 33594170

Abstract

Rash is one of the most common adverse events observed with mogamulizumab, an anti-C-C chemokine receptor 4 monoclonal antibody approved for previously treated mycosis fungoides (MF) and Sezary syndrome (SS). Given the nonspecific clinical presentations of this rash, histopathologic distinction from MF/SS is critical for informing clinical management. We performed a comprehensive characterization of the histopathologic findings in mogamulizumab-associated rash (MAR) with the integration of high-throughput sequencing of T-cell receptor (TCR) genes. Fifty-two biopsy specimens from 19 patients were evaluated retrospectively. Three major histologic reaction patterns were identified: spongiotic/psoriasiform dermatitis (33/52), interface dermatitis (11/52), and granulomatous dermatitis (8/52). Almost half of the specimens (21/52) showed at least 2 of these reaction patterns concurrently. Dermal eosinophils were not a consistent feature, being present in only half (27/52) of specimens and prominent in only 3. Features mimicking MF/SS, including lymphocyte exocytosis, lamellar fibroplasia, and adnexal involvement, were commonly seen but tended to be focal and mild. In 38/43 specimens with available immunohistochemistry, intraepidermal lymphocytes demonstrated a CD4:CD8 ratio 1:1. Low background levels of the patient's previously identified MF/SS-associated TCR sequence(s) were demonstrated in 20/46 specimens analyzed by high-throughput sequencing of TCR. We conclude that MAR may demonstrate diverse histologic features. Findings that may distinguish MAR from MF/SS include the inverted or normalized CD4:CD8 ratio within intraepidermal lymphocytes and demonstration of absent or nondominant levels of disease-associated TCR sequences. Correlation with the clinical findings and immunohistochemical and molecular characterization of the patient's MF/SS before mogamulizumab, when possible, may facilitate recognition of MAR.

View details for DOI 10.1097/PAS.0000000000001587

View details for PubMedID 32976123

View details for DOI 10.1007/s00259-020-05026-z

View details for PubMedID 32918110

View details for DOI 10.1111/cup.13812

View details for PubMedID 32681554

View details for DOI 10.1097/RHU.0000000000001408

View details for PubMedID 32496359

View details for DOI 10.1111/cup.13727

View details for PubMedID 32342514

Abstract

Dupilumab targets IL-4Ralpha and is used for moderate-to-severe atopic dermatitis (AD). Prior reports have described new alopecia areata (AA),1 flaring of prior AA,2 as well as improvement or resolution of AA3 in patients treated with dupilumab. We conducted a retrospective cohort study to describe the natural history of prior or new inflammatory alopecia in patients on dupilumab.

View details for DOI 10.1111/jdv.16094

View details for PubMedID 31737955

Abstract

Immunotherapies that block inhibitory checkpoint receptors on T cells have transformed the clinical care of patients with cancer1. However, whether the T cell response to checkpoint blockade relies on reinvigoration of pre-existing tumor-infiltrating lymphocytes or on recruitment of novel T cells remains unclear2-4. Here we performed paired single-cell RNA and T cell receptor sequencing on 79,046 cells from site-matched tumors from patients with basal or squamous cell carcinoma before and after anti-PD-1 therapy. Tracking T cell receptor clones and transcriptional phenotypes revealed coupling of tumor recognition, clonal expansion and T cell dysfunction marked by clonal expansion of CD8+CD39+ T cells, which co-expressed markers of chronic T cell activation and exhaustion. However, the expansion of T cell clones did not derive from pre-existing tumor-infiltrating T lymphocytes; instead, the expanded clones consisted of novel clonotypes that had not previously been observed in the same tumor. Clonal replacement of T cells was preferentially observed in exhausted CD8+ T cells and evident in patients with basal or squamous cell carcinoma. These results demonstrate that pre-existing tumor-specific T cells may have limited reinvigoration capacity, and that the T cell response to checkpoint blockade derives from a distinct repertoire of T cell clones that may have just recently entered the tumor.

View details for DOI 10.1038/s41591-019-0522-3

View details for PubMedID 31359002

Abstract

Survival in mycosis fungoides (MF) is varied and may be poor. The PROCLIPI (PROspective Cutaneous Lymphoma International Prognostic Index) study is a web-based data collection system for early-stage MF with legal data-sharing agreements permitting international collaboration in a rare cancer with complex pathology. Clinicopathological data must be 100% complete and in-built intelligence in the database system ensures accurate staging.To develop a prognostic index for MF.Predefined datasets for clinical, haematological, radiological, immunohistochemical, genotypic, treatment and quality of life are collected at first diagnosis of MF and annually to test against survival. Biobanked tissue samples are recorded within a Federated Biobank for translational studies.In total, 430 patients were enrolled from 29 centres in 15 countries spanning five continents. Altogether, 348 were confirmed as having early-stage MF at central review. The majority had classical MF (816%) with a CD4 phenotype (882%). Folliculotropic MF was diagnosed in 178%. Most presented with stage I (IA: 494%; IB: 428%), but 78% presented with enlarged lymph nodes (stage IIA). A diagnostic delay between first symptom development and initial diagnosis was frequent [856%; median delay 36 months (interquartile range 12-90)]. This highlights the difficulties in accurate diagnosis, which includes lack of a singular diagnostic test for MF.This confirmed early-stage MF cohort is being followed-up to identify prognostic factors, which may allow better management and improve survival by identifying patients at risk of disease progression. This study design is a useful model for collaboration in other rare diseases, especially where pathological diagnosis can be complex.

View details for DOI 10.1111/bjd.17258

View details for PubMedID 30267549

View details for DOI 10.1097/PCR.0000000000000284

View details for Web of Science ID 000457629000012

Abstract

Purpose: We report a patient with severe multi-organ dysfunction of unknown origin who presented with bilateral orbital and chorioretinal manifestations that led to the diagnosis of Erdheim-Chester Disease (ECD).Observations: ECD is a rare, histiocytic, proliferative disorder characterized by multi-systemic organ involvement that has historically lacked effective therapy. Our patient underwent genetic testing that was positive for the BRAF V600E mutation; therefore, the patient was treated with vemurafenib.Conclusions and importance: This case demonstrates the rare orbital and intraocular manifestations of ECD and the unfortunate impact of a delayed diagnosis, the importance of early gene therapy testing for management decisions, and the utilization of targeted directed therapy to improve visual outcomes and quality of life.

View details for PubMedID 30094395

View details for Web of Science ID 000429308603037

Abstract

Distinguishing classical dendritic cells from other myeloid cell types is complicated by the shared expression of cell surface markers. ZBTB46 is a zinc finger and BTB domain-containing transcription factor, which is expressed by dendritic cells and committed dendritic cell precursors, but not by plasmacytoid dendritic cells, monocytes, macrophages, or other immune cell populations. In this study, we demonstrate that expression of ZBTB46 identifies human dendritic cell neoplasms. We examined ZBTB46 expression in a range of benign and malignant histiocytic disorders and found that ZBTB46 is able to clearly define the dendritic cell identity of many previously unclassified histiocytic disease subtypes. In particular, all examined cases of Langerhans cell histiocytosis and histiocytic sarcoma expressed ZBTB46, while all cases of blastic plasmacytoid dendritic cell neoplasm, chronic myelomonocytic leukemia, juvenile xanthogranuloma, Rosai-Dorfman disease, and Erdheim-Chester disease failed to demonstrate expression of ZBTB46. Moreover, ZBTB46 expression clarified the identity of diagnostically challenging neoplasms, such as cases of indeterminate cell histiocytosis, classifying a fraction of these entities as dendritic cell malignancies. These findings clarify the lineage origins of human histiocytic disorders and distinguish dendritic cell disorders from all other myeloid neoplasms.

View details for PubMedID 29743654

Abstract

Primary cutaneous anaplastic large cell lymphoma (PC-ALCL) is a CD30+ lymphoproliferative disorder (LPD) of the skin with a relatively good prognosis in the absence of high-stage disease. CD30+ LPDs comprise approximately 25%-30% of primary cutaneous lymphomas and as a group represent the second most common clonal T-cell neoplasm of the skin behind mycosis fungoides. Diagnosis of PC-ALCL relies strongly on clinicopathologic correlation given the potential morphologic, clinical and molecular overlap with the other cutaneous CD30+ LPD, lymphomatoid papulosis, and more aggressive hematolymphoid neoplasms.

View details for DOI 10.1111/cup.12937

View details for PubMedID 28342276

View details for PubMedID 26438513