case_images: PMC9035957_01
case_images: Tumor of the right renal pelvis and sinus infiltrating the upper and middle thirds of the right ureter and right m. iliopsoas (arrows). CT of the abdomen with contrast enhancement. a Arterial phase, axial section at the level of the renal pelvis. b Venous phase, axial section at the level of the renal pelvis. c Excretory phase, coronal section at the level of the renal pelvis. d Excretory phase, coronal section at the level of the middle and lower thirds of the right ureter lumen.
case_images: cro-0015-0362-g01.jpg
case_images: PMC9035957_01_cro-0015-0362-g01.jpg
case_images: F1
case_images: Computed tomography (CT) revealed a contrast enhanced tumor, of the right kidney, 5.8 x 3.0 cm, which involved renal pelvis and renal sinus with the infiltration of upper and middle thirds of the right ureter and right m. iliopsoas (Fig. 1).
case_images: Morphoimmunohistochemical study of the renal pelvis tumor. a Tumor cells are small with rounded and "angular" nuclei (centrocytoid); individual larger cells (such as centroblasts) are discretely located in the infiltrate (hematoxylin and eosin staining x400). b Tumor cells express CD20 (immunohistochemical study x400). c. Tumor cells express BCL2 (immunohistochemical staining kh 400). d The tumor tissue contains foci of CD23 + disorganized network of follicular dendritic cells (immunohistochemical staining x200).
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case_images: PMC9035957_01_cro-0015-0362-g02.jpg
case_images: F2
case_images: Microscopically, the kidney tumor had the structure of a small round cell malignant tumor (Fig. 2a). The tumor cells expressed CD20 (Fig. 2b), BCL2 (Fig. 2c), and the marker of proliferative activity Ki67 was expressed in 7% of the cells. T lymphocytes, some of which expressed CD5, CD43, with numerous foci of CD23 + network of follicular dendritic cells (Fig. 2d). Thus, lymphoma of the marginal zone (MALT lymphoma) was verified morphoimmunohistochemically.
case_images: PMC9035957_02