case_images: PMC10257540_01
case_images: Computed tomography images of the abdomen: (a) before administration of the intravenous iodinated contrast, (b) corticomedullary phase, and (c) coronal reformatted image of the nephrographic phase, showing tissue with soft-tissue density surrounding the renal parenchyma and infiltrating the renal pelvis bilaterally. Note the slight dilatation of the bilateral collecting system resulting from extrinsic compression by the tissue. Positron emission tomography/computed tomography (PET-CT): no radiopharmaceutical uptake is seen on PET-CT as shown in (d) coronal PET, (e) axial PET, and (f) fusion of PET with tomographic image. Percutaneous biopsy confirmed the hypothesis of renal histiocytosis (Erdheim-Chester disease).
case_images: CRIHEM2023-4683188.001.jpg
case_images: PMC10257540_01_CRIHEM2023-4683188.001.jpg
case_images: fig1
case_images: Computed tomography (CT) at admission revealed a bilateral paravertebral formation with a soft tissue component, occupying bilateral perirenal spaces (Figures 1(a)-1(c)). On November 6, a CT-guided core biopsy of the perirenal lesion was performed (Figure 1), with histological results revealing fibrous tissue with infiltrate of plasma cells, lymphocytes, and histiocytes adjacent to renal parenchyma (Figure 2(a)).
case_images: Photomicrography. CT-guided core biopsy of the perirenal lesion. (a) Fibrous tissue with infiltrate of plasma cells, lymphocytes, and histiocytes (right) adjacent to renal parenchyma (left) (HE, 40x). (b) Immunohistochemical staining for CD68, highlighting the histiocytic infiltrate. CT: computed tomography.
case_images: CRIHEM2023-4683188.002.jpg
case_images: PMC10257540_01_CRIHEM2023-4683188.002.jpg
case_images: fig2
case_images: On November 6, a CT-guided core biopsy of the perirenal lesion was performed (Figure 1), with histological results revealing fibrous tissue with infiltrate of plasma cells, lymphocytes, and histiocytes adjacent to renal parenchyma (Figure 2(a)). In addition, immunohistochemical staining for CD68 highlighted a histiocytic infiltrate (Figure 2(b)).