A 14-year-old boy with no significant clinical history consulted with a 6-month history of febrile syndrome. Labs were significant for leukocytosis and elevated C-reactive protein and serum IgG levels, specifically IgG4. Computed tomography, magnetic resonance imaging, and PET/CT showed a right paradiaphragmatic anterior mediastinal mass of infiltrating appearance with intense heterogeneous enhancement (Figs. 1A–C) and marked hypermetabolism (Fig. 1D). Pathology study of a percutaneous biopsy revealed an inflammatory lesion associated with IgG4-related disease. The clinical picture resolved completely after 4 months of treatment with glucocorticoids (Fig. 1E).
Chest-abdomen-pelvis computed tomography with intravenous contrast in axial (A) and coronal (B) planes, showing the anterior mediastinal mass with heterogeneous enhancement and an infiltrative appearance (red arrows). T2-weighted MRI image with fat suppression (C) identifying the hyperintense anterior mediastinal mass (red arrow). The lesion was markedly hypermetabolic on the initial PET/CT images (SUVmax = 11.9) (D) and disappeared on PET/CT after 4 months of treatment (E).
IgG4-related disease is an entity associated with autoimmune mechanisms, characterized by elevated IgG4 serum levels, fibrosis, tissue infiltration by IgG4-secreting plasma cells, and response to glucocorticoids1.
Mediastinal involvement usually manifests as lymphadenopathies, either in isolation or concomitantly with the enlargement of other organs1. Presentation in the form of a mass is exceptional2.
In the case of a patient with a mediastinal mass, IgG4-related disease should be included in the differential diagnosis. Proper diagnosis and conservative treatment can prevent unnecessary invasive diagnostic or therapeutic procedures and their associated comorbidities.
Please cite this article as: Rabadán-Caravaca MD, Ruiz-Carazo E, García-Roa MD. Masa mediastínica anterior asociada a síndrome febril como única manifestación de enfermedad relacionada con IgG4. Arch Bronconeumol. 2021;57:702.
