Unusual Coincidence: Concurrent Cast Nephropathy and Lymphoma Infiltration in an Influenza A-Associated Acute Kidney Injury

Figure 1

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.

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