2026-07-12 | Large Progressive Right Coronary Artery Aneurysm Secondary to IgG4 Disease.
Coronary artery aneurysm is a rare but well recognized manifestation of immunoglobulin G4 (IgG4)-related disease, with a paucity of data to guide its management. A 62-year-old man with known IgG4-related disease diagnosed 2 years prior presented for routine clinic follow-up. Despite being asymptomatic and remaining in serologic remission, imaging demonstrated marked progression of a large right coronary artery aneurysm measuring 62 mm × 72 mm. Given prohibitive operative risks, immunosuppressive therapy was intensified with close imaging follow-up. Published experience with IgG4-related coronary artery aneurysm is limited to small case series, with highly variable management strategies and outcomes. To the authors' knowledge, this case represents the largest conservatively managed IgG4-related coronary aneurysm reported. IgG4-related coronary aneurysms may progress silently with disassociation between serologic remission and disease progression on imaging. Multidisciplinary decision-making is critical to optimize outcomes in this high-risk condition, particularly with regard to the surveillance strategy in patients who otherwise achieve biochemical remission.
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2026-07-10 | From inflammatory initiation to fibrotic remodeling: mechanisms and precision therapeutic strategies in otorhinolaryngologic involvement of IgG4-related disease.
IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder characterized by complex immune-mediated mechanisms and broad organ involvement that remains substantially underdiagnosed in clinical practice. The head and neck region is one of the most commonly involved anatomical domains, encompassing the major salivary glands, lacrimal glands, nasal cavity and paranasal sinuses, larynx and subglottis, thyroid gland, middle ear, orbit, and cervical lymph nodes. This review integrates current understanding of the immunopathological mechanisms underlying IgG4-RD with organ-specific clinical features and therapeutic considerations across these head and neck subregions. The core immune pathogenesis involves clonally expanded CD4+ cytotoxic T lymphocytes and activated follicular helper T cells that, within a Th2-skewed cytokine environment, promote IgG4 class-switch recombination and plasmablast expansion, driving the transition from inflammatory infiltration to progressive fibrotic remodeling. Although head and neck subtypes share this common immunopathological framework, they differ considerably in the relative balance between inflammatory and fibrotic features, clinical severity, and organ-specific risk profiles. These differences may reflect local microenvironmental factors, including epithelial characteristics, innate immune responsiveness, and the functional properties of resident stromal fibroblasts, though the precise mechanisms remain to be fully established. Therapeutically, glucocorticoids remain the standard first-line treatment for remission induction but are limited by high relapse rates after withdrawal. Rituximab has demonstrated efficacy in refractory and relapsing disease. Inebilizumab, an anti-CD19 monoclonal antibody, has shown significant benefit in a phase III randomized controlled trial. Dupilumab, which targets the IL-4/IL-13 signaling axis, has shown potential in case reports and small series, but prospective validation is required before it can be recommended as a standard therapeutic option. By mapping organ-specific immunopathological differences onto differentiated therapeutic approaches, this review aims to support a more individualized, biologically informed framework for managing IgG4-RD in the head and neck.
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2026-07-06 | Spinal nerve root IgG4-related inflammatory pseudotumor mimicking a malignant spinal tumor: a case report.
IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder characterized by tumefactive lesions, dense infiltration of IgG4-positive plasma cells, and variable organ involvement. Inflammatory pseudotumors associated with IgG4-RD are uncommon, and spinal nerve root involvement is exceedingly rare. Such lesions may closely mimic malignant spinal tumors on imaging, posing significant diagnostic challenges. We report the case of a 55-year-old woman who presented with progressive lower back pain and urinary incontinence. Magnetic resonance imaging revealed a space-occupying lesion in the left L1/2 intervertebral foramen. ^18F-FDG positron emission tomography-computed tomography (PET-CT) demonstrated intense focal hypermetabolism with a markedly elevated maximum standardized uptake value (SUVmax) of 11.95, strongly suggesting a malignant process. The patient underwent surgical decompression and tumor resection. Histopathological examination revealed a fibroinflammatory lesion with dense lymphoplasmacytic infiltration and abundant IgG4-positive plasma cells (45/HPF in hotspots), consistent with an IgG4-related inflammatory pseudotumor, despite normal serum IgG4 levels. This case highlights that, despite strong radiological suspicion for malignancy, preoperative biopsy may allow diagnosis of IgG4-RD and enable corticosteroid therapy, potentially avoiding unnecessary radical surgery.
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