PMC9035957_01
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.
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F1
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).
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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F2
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.
PMC9035957_02