case_images: PMC10923615_01
case_images: Kidney biopsy with (a) hematoxylin and eosin stain showing atypical tubular casts with sharp-edged or fractured appearance with atypical lymphoid cells around glomerulus. (b) Those atypical lymphoid cells were CD20 positive. (c and d) By immunofluorescence, these atypical casts are strongly positive for kappa staining but nonreactive for lambda staining.
case_images: CRIN2024-5524746.001.jpg
case_images: PMC10923615_01_CRIN2024-5524746.001.jpg
case_images: fig1
case_images: Notably, there was an infiltration of abnormal lymphoid cells, which were found to be responsive to CD20 and unresponsive to CD3 and cyclin D1, as shown in Figure 1.
case_images: Positron emission tomography (PET) scan displayed mild and diffusely increased uptake (score 4, uptake slightly to moderately higher than liver) at the spleen with splenomegaly, compatible with lymphoma involvement.
case_images: CRIN2024-5524746.002.jpg
case_images: PMC10923615_01_CRIN2024-5524746.002.jpg
case_images: fig2
case_images: A positron emission tomography (PET) scan displayed slight and widespread uptake in the spleen, coinciding with splenomegaly (Figure 2).
case_images: Bone marrow biopsy with (a) hematoxylin and eosin stain showing small clusters of small lymphoid cells with interstitial infiltration of about 40% and (b) the neoplastic cells are positive for CD20, compatible with low-grade mature B-cell neoplasm.
case_images: CRIN2024-5524746.003.jpg
case_images: PMC10923615_01_CRIN2024-5524746.003.jpg
case_images: fig3
case_images: MYD88 mutation test was negative for L265P (Figure 3).