Langerhans cell histiocytosis presenting as an isolated brain tumour:A case report

Langerhans cell histiocytosis(LCH)is a rare proliferative histiocyte disorder.It can affect any organ or system,especially the bone,skin,lung,and central nervous system(CNS).In the CNS,the hypothalamic-pituitary is predominantly affected,whereas the brain parenchyma is rarely affected.LCH occurring in the brain parenchyma can be easily confused with glioblastoma or brain metastases.Thus,multimodal imaging is useful for the differential diagnosis of these intracerebral lesions and detection of lesions in the other organs.CASE SUMMARY A 47-year-old man presented with a headache for one week and sudden syncope.Brain computed tomography(CT)and magnetic resonance imaging showed an irregularly shaped nodule with heterogeneous enhancement.On^(18)F-fluorodeoxyglucose(^(18)F-FDG)positron emission tomography/CT,a nodule with^(18)F-FDG uptake and multiple cysts in the upper lobes of both lungs were noted,which was also confirmed by high-resolution CT.Thus,the patient underwent surgical resection of the brain lesion for further examination.Postoperative pathology confirmed LCH.The patient received chemotherapy after surgery.No recurrence was observed in the brain at the 12-mo follow-up.CONCLUSION Multimodal imaging is useful for evaluating the systemic condition of LCH,developing treatment plans,and designing post-treatment strategies.

Shifting focus from bacteria to host neutrophil extracellular traps of biodegradable pure Zn to combat implant centered infection

The widespread use of orthopedic implants to support or replace bones is increasingly threatened by the risk of incurable bacterial infections,impenetrable microbial biofilms,and irreversible antibiotic resistance.In the past,the development of anti-infective biomaterials focused solely on direct antibacterial properties while ignoring the host’s immune response.Inspired by the clearance of infection by the innate neutrophil response and partici-pation in anti-infectious immunity of Zn ions,we report an innovative neutrophil extracellular traps(NETs)strategy,induced by biodegradable pure Zn,which achieved therapeutic efficacy toward biomaterial-related infections.Our in vitro and in vivo data showed that pure Zn was favorable for NETs formation by promoting the release of DNA fibers and granule proteins in a reactive oxygen species(ROS)-dependent manner,thereby retraining and degrading bacteria with an efficiency of up to 99.5%.Transcriptome analysis revealed that cytoskeletal rearrangement and toll-like receptor(TLR)signaling pathway were also involved in Zn-induced NETs formation.Furthermore,the in vivo results of a Staphylococcus aureus(S.aureus)-infected rat model veri-fied that pure Zn potentiated the bactericidal capability of neutrophils around implants,and promoted osseointegration in S.aureus-infected rat femurs.This antibacterial immunity concept lays a foundation for the development of other antibacterial biomaterials and holds great promise for treating orthopedic infections.

Sympathetic paraganglioma in the pericardium with paraganglioma syndrome 3:Multimodality imaging findings

To the Editor:Sympathetic paraganglioma in the pericardium is rare,which can be life-threatening.It presents with symptoms,such as refractory hypertension,palpitations,and other hormone-related manifestations.