Typical Bone Scintigraphy Presentation of Erdheim-Chester Disease in a Patient Diagnosed With IgG4-Related Disease.

ABSTRACT: A 50-year-old woman presented a dry syndrome, joint pain, inflammatory syndrome, polyclonal hypergammaglobulinemia, and tubulointerstitial nephritis. Imaging studies (including FDG PET/CT) revealed infrarenal retroperitoneal fibrosis with periaortitis and hypermetabolic osteosclerotic lesions. Bone scintigraphy demonstrated intense uptake in the femoral, tibial, and radial regions, suggestive of non-Langerhans histiocytosis, specifically Erdheim-Chester disease. A bone biopsy confirmed the presence of IgG4-positive plasma cells but no histiocytes. The patient received corticosteroid therapy followed by rituximab, resulting in a complete response. This case suggests an atypical manifestation of bone lesions in IgG4-related disease, emphasizing the diagnostic challenge between IgG4-related disease and Erdheim-Chester disease.

A "Leopard Man" Aspect on 18 F-FDG PET/CT Revealing a VEXAS Syndrome.

ABSTRACT: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an adult-onset autoinflammatory disease caused by somatic UBA1 mutations first described in 2020. Most of these patients met clinical criteria for an inflammatory syndrome (relapsing polychondritis, Sweet syndrome, polyarteritis nodosa, or giant-cell arteritis) or a hematologic condition (myelodysplastic syndrome or multiple myeloma) or both. We described here an FDG PET/CT "leopard man" appearance, with abnormal marrow recruitment the findings, in a 70-year-old man diagnosed with a VEXAS syndrome.

Unexpected cure of a toxic nodule in a multinodular goiter induced by immune checkpoint inhibitors: a case report.

Introduction: Immune checkpoint inhibitors (ICI) are used to treat cancers including metastatic melanomas and can induce endocrine side effects. The thyroid is frequently affected with classically transient thyrotoxicosis followed by hypothyroidism. The evolution of thyroid nodules and goiters under ICI therapy is poorly described. Case presentation: A 72-year-old male presenting with hyperthyroidism due to a toxic nodule in a multinodular goiter (MNG) started ICI therapy combining ipilimumab and nivolumab to treat metastatic melanoma. After an initial worsening of thyrotoxicosis, treated with carbimazole, he developed profound hypothyroidism, persisting after carbimazole discontinuation, needing a long-term levothyroxine supplementation. Ultrasound control performed 6 months after ICIs treatment initiation revealed diffuse thyroid atrophy with involution of all nodules. 123I-scintigraphy confirmed a destructive mechanism. Discussion: The evolution of MNG and toxic nodules is poorly described in patients treated with ICI since systematic US evaluations are lacking. We describe for the first time a toxic nodule cured by ICI therapy inducing destructive thyroiditis. Conclusion: Pre-existing nodules and MNG, even if toxic, are not a contraindication for ICI treatment provided the patients are carefully monitored.

Fluorodeoxyglucose positron emission tomography-computed tomography findings in a first series of 10 patients with polyarteritis nodosa.

OBJECTIVE: 18F-fluorodeoxyglucose PET/CT (FDG-PET/CT) is widely used in patients with large vessel vasculitis. The benefits of FDG-PET/CT in PAN has only ever been assessed in three case reports. Our aim was to describe FDG-PET/CT findings in 10 patients with newly diagnosed PAN. METHODS: This was a retrospective study of patients with PAN who underwent FDG-PET/CT at diagnosis between 2017 and 2020. The FDG-PET/CT data were analysed retrospectively. RESULTS: Ten patients were included: nine men and one woman with a median age of 67 years (range 43-78). PAN was diagnosed according to ACR criteria in nine patients and histologically in one. All patients had high CRP levels (median 223 mg/l). The main FDG-PET/CT abnormality was increased tracer uptake in the muscles, particularly in the connective tissue (perimysium, epimysium) (n = 7), and in linear (n = 5) or focal (n = 2) patterns. Increased FDG uptake in large-diameter vessels was observed in four patients, in the humeral (n = 4), femoral (n = 1) and common interosseous arteries (n = 1). Nine patients had bone marrow FDG uptake and six had splenic FDG uptake. Three had synovitis and three had lymph node uptake. One patient had subcutaneous FDG uptake with a 'leopard skin' appearance. CONCLUSIONS: FDG-PET/CT seems to be a useful non-invasive imaging technique for diagnosing PAN, particularly in patients with non-specific systemic features. Tracer uptake in muscular connective tissue seems to be a recurrent sign in patients with PAN and may be pathognomonic.

A Warp-Knitted Light-Emitting Fabric-Based Device for In Vitro Photodynamic Therapy: Description, Characterization, and Application on Human Cancer Cell Lines.

Photodynamic therapy (PDT) appears to be a promising strategy in biomedical applications. However, the complexity of its parameters prevents wide acceptance. This work presents and characterizes a novel optical device based on knitted light-emitting fabrics and dedicated to in vitro PDT involving low irradiance over a long illumination period. Technical characterization of this device, called CELL-LEF, is performed. A cytotoxic study of 5-ALA-mediated PDT on human cancer cell lines is provided as a proof of concept. The target of delivering an irradiance of 1 mW/cm2 over 750 cm2 is achieved (mean: 0.99 mW/cm2; standard deviation: 0.13 mW/cm2). The device can maintain a stable temperature with the mean thermal distribution of 35.1 °C (min: 30.7 °C; max: 38.4 °C). In vitro outcomes show that 5-ALA PDT using CELL-LEF consistently and effectively induced a decrease in tumor cell viability: Almost all the HepG2 cells died after 80 min of illumination, while less than 60% of U87 cell viability remained. CELL-LEF is suitable for in vitro PDT involving low irradiance over a long illumination period.