[1499] Hematologic Malignancies in Native Renal Biopsies: Report of 35 Cases.

Christine A VanBeek, Cynthia C Nast, Arthur H Cohen, Jerry Hussong, Mark Haas. Cedars-Sinai Medical Center, Los Angeles, CA

Background: Primary renal hematologic malignancies are rare, while secondary renal involvement is a known complication of lymphomas and leukemias. As they seldom cause renal failure, leukemic/lymphomatous infiltrates of the kidney are rarely biopsied and their frequency in native kidney biopsies is not well documented.
Design: Of 13,828 non-transplant medical renal biopsies examined from 2004-2010, 35 with hematologic malignancies were identified. Light, immunofluorescence, and electron microscopies, immunohistochemistry, and clinical information were reviewed.
Results: There were 29 males and 5 females, ages 18 – 89 (mean 62). In 12 cases (34%) the renal biopsy provided the first diagnosis of malignancy including intravascular large B-cell (2), T-cell (2), diffuse large B cell (DLBCL) (4), chronic lymphocytic leukemia (CLL) and other low grade B-cell (4) lymphomas. Cases with prior neoplastic history included CLL and other low grade B-cell lymphomas (18), myeloid leukemia (2), DLBCL (1), and B-(1) and T-(1) acute lymphoblastic leukemia. The intravascular lymphomas involved glomerular capillaries causing hematuria and proteinuria, whereas the other 9 high grade lymphomas produced acute renal failure (ARF) with interstitial infiltration, often involving >80% of the parenchyma. One case of DLBCL also presented with nephrotic syndrome (membranous glomerulopathy). In contrast, low grade neoplasms typically involved <30% of the parenchyma and in 20/24 (83%) co-existing pathology was the cause of renal symptoms. In one case of CLL, atypical lymphocytes in glomeruli produced a membranoproliferative pattern without immune complexes, with hematuria and proteinuria. Ten cases of low-grade B cell lymphoma showed paraprotein-associated lesions, including 4 cases of immunotactoid glomerulonephritis (GN). Other concurrent lesions were minimal change nephropathy, immune complex GN, diabetic nephropathy, nodular glomerulosclerosis, pauci-immune crescentic GN and tubulo-interstitial diseases. Of the 2 myeloid leukemias, one showed neoplastic cells in 90% of the parenchyma with ARF, and in the other immature myeloid cells intermixed with inflammation of interstitial nephritis.
Conclusions: Hematologic malignancies were found in 0.25% of native renal biopsies performed to evaluate non-neoplastic diseases. In 1/3 of cases, the renal biopsy provided the first diagnosis of lymphoid neoplasm. High grade malignancies cause a variety of renal symptoms depending on histologic distribution. Low grade malignancies are typically incidental findings. Recognition of these neoplasms is important for appropriate clinical management.
Category: Kidney (does not include tumors)

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 252, Wednesday Afternoon

 

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