case_images: PMC11272546_01
case_images: (A) Picture revealing the patient's left neck mass (red arrows) (B) PET-CT scan reveals a high uptake of tracer in left cervical lymphonodes. (yellow arrows). (C) Lymph node showing zone of eosinophil-rich polimormorphic infiltrate, proliferation of reactive endothelium, and interstitial collagen deposition in a nodular fashion (black asterisk). The rest of the nodal parenchyma reveals numerous reactive lymphoid follicles (black arrow) (HE, 100x). (D) High magnification of the eosinophil-rich polymorphic infiltrate (HE, 400x).
case_images: fimmu-15-1404954-g001.jpg
case_images: PMC11272546_01_fimmu-15-1404954-g001.jpg
case_images: f1
case_images: A cervical computerized tomography (CT) evidenced multiple confluents and enlarged lymph nodes in the left cervical ( Figure 1A ) and supraclavicular areas. Those lymph nodes exhibited high tracer uptake in the PET-CT scan ( Figure 1B ). A cervical lymph node biopsy revealed proliferation of polymorphic cell consisting of plasma cells, mature lymphocytes ( Figure 1C ), and a dense infiltrate of eosinophils ( Figure 1D ).
case_images: (A) Glomeruli show mild mesangial cell hipercellularity and matrix expansion (PAS, 400x). (B) The capillary walls are slightly thickened, and spikes are visible on Jones silver stain (400x + zoom). Immunofluorescence microscopy revealed diffuse granular deposits of IgA on mesangium and paramesangium [(C), 400x], and IgG was diffusely positive on capillary walls, with a membranous pattern [(D), 400x]. Immunohistochemistry staining for PLA2R [(E), 400x] and IgG4 [(F), 400x] were positive on capillary walls with a global and diffuse distribution. Electron microscopy shows subepithelial deposits (red arrow head) with surrounding basement membrane reaction, global podocyte foot process effacement [(G), 3,700x], large electron-dense mesangial deposits (red arrow), and increased matrix [(H), 8,900x].
case_images: fimmu-15-1404954-g002.jpg
case_images: PMC11272546_01_fimmu-15-1404954-g002.jpg
case_images: f2
case_images: Light microscopy revealed the expansion of the mesangial matrix and glomerular basement membrane ( Figure 2A ) thickness with spike-like projections ( Figure 2B ). IgA (+2/+3) in the mesangium ( Figure 2C ), for IgG (+2/+3) ( Figure 2D ) and C3 (+2/+3) in capillary walls, and for kappa and lambda (+2/+3) in capillary walls and the mesangium. Immunohistochemistry highlighted a positive global and diffuse staining for PLA2R ( Figure 2E ) and IgG4 ( Figure 2F ) on capillary walls. Electron microscopy revealed electron-dense deposits in the subepithelial and mesangial region ( Figures 2G, H ).