Kidney involvement in Rosai-Dorfman disease.

A 32-year-old woman was referred to us for bilateral hydroureteronephrosis due to suspected idiopathic retroperitoneal fibrosis, for which she had received several immunosuppressive therapies (i.e., glucocorticoids, rituximab, and tocilizumab) without benefit. No previous imaging scans were available for review. An abdominal computed tomography revealed bilateral massive pararenal lesions extending into the renal pelvis (Figure 1). The lesions had high metabolic activity at 18fluorodeoxyglucose positron emission tomography, which also showed signs of diffuse sinusitis with osteosclerosis of facial bones and 18fluorodeoxyglucose-avid osteosclerotic lesions involving femurs, tibias, and tarsal bones (Supplementary Figure S1). We performed a computed tomography–guided biopsy of the left pararenal mass; histology showed fibrous stroma and polymorphic inflammatory infiltrates with S100+, CD1a- histiocytes displaying signs of emperipolesis (Figure 2). These findings were consistent with Rosai-Dorfman disease (RDD). Histologic re-evaluation of a previous sinus polypectomy revealed similar findings. Phospho–extracellular signal–regulated kinase immunostaining showed histiocytes with low cytoplasmic and nuclear positivity (Supplementary Figure S2). No mutations of genes involved in the mitogen-activated protein kinase and phosphatidylinositol-3′-kinase/AKT pathways (Supplementary Table S1) were detected on the biopsy sample. Figure 2Histopathologic findings of the right perirenal mass. (a) Hematoxylin and eosin staining shows histiocytes with abundant acidophilic cytoplasm and a polymorphous infiltrate; emperipolesis, that is, the presence of cells within the cytoplasm of histiocytes, can be seen (arrow). Original magnification ×40. Intense immunostaining for (b) S-100 and (c) CD68-KP1 also decorates histiocytes with emperipolesis (arrows). S-100 and CD68-KP1 immunohistochemistry staining, original magnification ×60. To optimize viewing of this image, please see the online version of this article at www.kidney-international.org. View Large Image Figure Viewer Download Hi-res image in this issueKidney InternationalVol. 103Issue 1PreviewTransplantation of large organs, such as the intestine or liver, can result in hematopoietic chimerism, presumably because sufficient donor hematopoietic stem cells reside within the transplanted tissue. This was not thought to be possible with transplantation of a single kidney. Sobrino et al. disproved this notion by describing the events that occurred in a child who received a kidney allograft from a deceased donor after developing kidney failure in the setting of Schimke immune-osseous dysplasia, an autosomal recessive disorder that includes primary combined immune deficiency along with podocyte dysfunction, leading to focal segmental glomerulosclerosis. Full-Text PDF