Malignant Dendritic Cell Sarcomas in the Skin: 2 Cases of Rare Sarcoma Subtypes With Literature Review.

ABSTRACT: Interdigitating dendritic cell sarcoma is a rare, aggressive hematological malignancy primarily originating in lymph nodes, with only 10 reported cases presenting in the skin (primary cutaneous interdigitating dendritic cell sarcoma). Past presentations showed erythematous nodules on the proximal extremities, back, or face. Morphologically, these neoplasms are similar to melanomas and other dendritic cell (DC) tumors, making their diagnosis difficult. Here, we present 1 case of primary cutaneous interdigitating dendritic cell sarcomas and another 1 of malignant indeterminate dendritic cell tumor (indeterminate DC sarcoma). The first case is an 83-year-old man who presented with recent ulceration and bleeding of an asymptomatic, slow growing lesion on his right thigh with biopsy revealing a large, well-circumscribed polypoid spindle cell tumor in the dermis with atypical cells with vesicular nuclei in a lymphoplasmacytic background and immunohistochemistry positivity for CD45, CD68, S100, and Cyclin D1. The second case is a 74-year-old man who presented with a progressively darkening and enlarging abdominal skin lesion with biopsy revealing a diffuse infiltrate of atypical poorly differentiated pleomorphic nuclear cells and immunohistochemistry positivity for S100, CD1a, CD56, CD43, cyclin D1, CD31, CD4, and BRAF V600E. Our findings contribute to expand the reported literature on primary cutaneous DC sarcomas.

Artificial Intelligence Models Are Limited in Predicting Clinical Outcomes Following Hip Arthroscopy: A Systematic Review.

BACKGROUND: Hip arthroscopy has seen a significant surge in utilization, but complications remain, and optimal functional outcomes are not guaranteed. Artificial intelligence (AI) has emerged as an effective supportive decision-making tool for surgeons. The purpose of this systematic review was to characterize the outcomes, performance, and validity (generalizability) of AI-based prediction models for hip arthroscopy in current literature. METHODS: Two reviewers independently completed structured searches using PubMed/MEDLINE and Embase databases on August 10, 2022. The search query used the terms as follows: (artificial intelligence OR machine learning OR deep learning) AND (hip arthroscopy). Studies that investigated AI-based risk prediction models in hip arthroscopy were included. The primary outcomes of interest were the variable(s) predicted by the models, best model performance achieved (primarily based on area under the curve, but also accuracy, etc), and whether the model(s) had been externally validated (generalizable). RESULTS: Seventy-seven studies were identified from the primary search. Thirteen studies were included in the final analysis. Six studies (n = 6,568) applied AI for predicting the achievement of minimal clinically important difference for various patient-reported outcome measures such as the visual analog scale and the International Hip Outcome Tool 12-Item Questionnaire, with area under a receiver-operating characteristic curve (AUC) values ranging from 0.572 to 0.94. Three studies used AI for predicting repeat hip surgery with AUC values between 0.67 and 0.848. Four studies focused on predicting other risks, such as prolonged postoperative opioid use, with AUC values ranging from 0.71 to 0.76. None of the 13 studies assessed the generalizability of their models through external validation. CONCLUSION: AI is being investigated for predicting clinical outcomes after hip arthroscopy. However, the performance of AI models varies widely, with AUC values ranging from 0.572 to 0.94. Critically, none of the models have undergone external validation, limiting their clinical applicability. Further research is needed to improve model performance and ensure generalizability before these tools can be reliably integrated into patient care. LEVEL OF EVIDENCE: Level IV. See Instructions for Authors for a complete description of levels of evidence.

Extranodal Marginal Zone Mucosa-Associated Lymphoid Tissue Lymphoma of the Gallbladder: A Case Report and Literature Review.

We describe the case of a patient with extranodal marginal zone mucosa-associated lymphoid tissue (MALT) lymphoma of the gallbladder discovered incidentally after elective cholecystectomy. A 76-year-old female with a history of non-Hodgkin's lymphoma of the right breast and rectal cancer stage Tis requiring trans-anal excision presented with chronic intermittent abdominal pain. Computed tomography (CT) scan showed multiple calcified gallstones impacted in the gallbladder, with no evidence of enlarging lymphadenopathy indicating an elective cholecystectomy. The intra- and post-operative courses were unremarkable, but pathology review revealed immunohistochemistry positive for CD20 and BCL-2 with a Ki67 proliferation index of 5%, which was diagnostic of extranodal marginal zone MALT lymphoma of the gallbladder. The patient was followed up by a medical oncologist, and after extensive discussion, the decision was made to continue observation with close monitoring without systemic chemotherapy given the asymptomatic presentation. We also examined the pertinent literature to MALT lymphoma of the gallbladder and discussed theories suggested for its pathophysiology.

Broad and potently neutralizing monoclonal antibodies isolated from human survivors of New World hantavirus infection.

New World hantaviruses (NWHs) are endemic in North and South America and cause hantavirus cardiopulmonary syndrome (HCPS), with a case fatality rate of up to 40%. Knowledge of the natural humoral immune response to NWH infection is limited. Here, we describe human monoclonal antibodies (mAbs) isolated from individuals previously infected with Sin Nombre virus (SNV) or Andes virus (ANDV). Most SNV-reactive antibodies show broad recognition and cross-neutralization of both New and Old World hantaviruses, while many ANDV-reactive antibodies show activity for ANDV only. mAbs ANDV-44 and SNV-53 compete for binding to a distinct site on the ANDV surface glycoprotein and show potently neutralizing activity to New and Old World hantaviruses. Four mAbs show therapeutic efficacy at clinically relevant doses in hamsters. These studies reveal a convergent and potently neutralizing human antibody response to NWHs and suggest therapeutic potential for human mAbs against HCPS.

Nanoceria: Metabolic interactions and delivery through PLGA-encapsulation.

Cerium oxide nanoparticles (nanoceria) have recyclable antioxidative activity. It has numerous potential applications in biomedical engineering, such as mitigating damage from burns, radiation, and bacterial infection. This mitigating activity is analogous to that property of metabolic enzymes such as superoxide dismutase (SOD) and catalase - scavengers of reactive oxygen species (ROS). Therefore, nanoceria can protect cells from environmental oxidative stress. This therapeutic effect prompted studies of nanoceria and metabolic enzymes as a combination therapy. The activity and structure of SOD, catalase, and lysozyme were examined in the presence of nanoceria. A complementary relationship between SOD and nanoceria motivated the present work, in which we explored a method for simultaneous delivery of SOD and nanoceria. The biocompatibility and tunable degradation of poly(lactic-co-glycolic acid) (PLGA) made it a candidate material for encapsulating both nanoceria and SOD. Cellular uptake studies were conducted along with a cytotoxicity assay. The antioxidative properties of PLGA-nanoceria-SOD particles were verified by adding H2O2 to cell culture and imaging with fluorescent markers of oxidative stress. Our results suggest that PLGA is a suitable encapsulating carrier for simultaneous delivering nanoceria and SOD together, and that this combination effectively reduces oxidative stress in vitro.