case_images: PMC11225528_01
case_images: (a and b) The right S1 and S2 nerve roots (white arrowheads) appear swollen and enhanced with the contrast agent. The hypertrophic lumbar dura (white arrowhead) appears partially enhanced (a) coronal T1-weighted gadolinium-enhanced image and (b) sagittal T1-weighted gadolinium-enhanced image. (c) Intraoperatively, reddish and swollen S1 nerve roots can be observed on opening the dura; (d and e) lymphocyte aggregation was accompanied by the diffuse growth of fibrous tissue (hematoxylin-eosin staining with original magnification x100 (d) and original magnification x400 (e). (f and g) The specimen is positive for CD3 (original magnification, x400) and CD20 (original magnification, x200). (h)The left dilated ureter (white arrowheads) and bilateral perirenal lesions (white arrows) can be observed on contrast-enhanced computed tomography.
case_images: SNI-15-197-g001.jpg
case_images: PMC11225528_01_SNI-15-197-g001.jpg
case_images: F1
case_images: T1-weighted gadolinium-enhanced imaging. The dura appeared partially hypertrophic and enhanced [Figures 1a and b]. A soft, reddish lesion of the S1 nerve root was sampled for pathological evaluation [Figure 1c]. The harvested tissue showed the presence of aggregated lymphocytes, surrounded by diffusely growing fibrous tissue, and was positive for CD3 and CD20 [Figures 1d-g]. Abdominal contrast-enhanced computed tomography (CT) was performed to rule out an abdominal lesion and revealed a dilated left ureter and bilateral perirenal lesions [Figure 1h].
case_images: (a and b) The specimen of the right S1 nerve exhibits dense lymphoplasmacytic infiltration, obliterative phlebitis, and storiform growth of collagen fibers (a and b: hematoxylin-eosin staining, original magnification x100). (c and d) The specimen is positive for immunoglobulin G (IgG) (c: original magnification x200) and IgG4 (d: original magnification x200), and more than half of the tissue positive for IgG is positive for IgG4. (e-g) The ureter specimen shows similar findings on hematoxylin-eosin staining (e), immunostaining of IgG (f), and that of IgG4 (g) (original magnification x200).
case_images: SNI-15-197-g002.jpg
case_images: PMC11225528_01_SNI-15-197-g002.jpg
case_images: F2
case_images: Storiform patterns of collagen fibers and obliterating phlebitis were observed [Figure 2].