Malignant B-cell lymphoma in renal cyst wall

Mucosa-associated lymphoid tissue lymphoma involving the kidney: a case report and review of the literature

Mucosa-associated lymphoid tissue (MALT) lymphomas arise from various anatomic sites, mostly observed in the gastrointestinal tract; however, involvement of the kidney is extremely rare. We report a case of MALT lymphoma involving the kidney in a 70-year-old man. Radical nephrectomy was performed under the diagnosis of renal cell carcinoma preoperatively. However, the renal specimen showed that the diffuse small- to medium-sized lymphocytes were scattered and formed colonies, and the neoplastic lymphoid cells were positive for CD20, CD79α, and Bcl-2, but negative for CD10 and Cyclin D1; therefore, the final histological diagnosis was MALT lymphoma involving the renal pelvis. Although he was referred to the department of hematology, no additional treatment was given postoperatively, and he has survived for 4 months without evidence of a recurrence of lymphoma at the last follow-up. To the best of our knowledge, to date 37 reports of MALT lymphoma involving the kidney have been published in the literature. We report a case of MALT lymphoma involving the kidney, and review the existing literature.

Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation Arising in a Renal Pseudocyst

Primary renal lymphomas are very rare, and primary kidney-limited lymphomas with cystic presentation have never been described before. This study reports a case of diffuse large B-cell lymphoma associated with chronic inflammation occurring in a renal pseudocyst: an infrequent neoplasm with an unusual and subtle clinical presentation.

MALT lymphoma involving the kidney: a report of 10 cases and review of the literature

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) can arise at any anatomic site, but involvement of the kidney is rare. We describe 10 cases of kidney MALT lymphoma, including 6 localized cases. No predisposing inflammatory conditions were identified, with the possible exception of coexistent renal Actinomyces infection in 1 case. We performed fluorescence in situ hybridization (FISH) using a malt1 break-apart probe in 7 cases. A malt1 gene rearrangement was identified in 1 case (14%). This case was further assessed by FISH using an IgH breakapart probe that showed IgH gene rearrangement. These results are suggestive of the t(14;18) involving malt1 and IgH. Immunostaining for NF-kappaB p65 showed nuclear positivity, consistent with NF-kappaB activation, in 3 of 5 cases assessed. Our results indicate that kidney MALT lymphomas share similarities with MALT lymphomas arising at other sites in that MALT lymphoma-associated translocations and NF-kappaB activation occur in a subset of cases.

Imaging of renal lymphoma: patterns of disease with pathologic correlation

Extranodal spread of lymphoma often affects the genitourinary system, with the kidneys being the most commonly involved organs. Contrast material-enhanced computed tomography (CT) remains the modality of choice for the detection, diagnosis, staging, and monitoring of renal lymphoma. Magnetic resonance (MR) imaging is particularly useful in patients in whom intravenous administration of iodinated contrast material is contraindicated. Ultrasonography (US), although very valuable for diagnosing lymphoma in the testis or epididymis, is less sensitive than CT and MR imaging for detecting renal lymphoma. Typical imaging findings of renal lymphoma include multiple poorly enhancing or hypoechoic masses, retroperitoneal tumors directly invading the kidneys, bilateral renal enlargement, and perirenal soft-tissue masses. Cystic lesions and tumors predominantly affecting the renal sinus and collecting system are uncommon. Unless the renal lesions manifest in the setting of widespread lymphoma, percutaneous biopsy is indicated to differentiate lymphoma from metastases, hypovascular renal cell carcinoma, uroepithelial carcinoma, or atypical infection, with US routinely being used to guide the procedure. Current immunohistochemical techniques allow accurate diagnosis and characterization of renal lymphoma. Radiologists should be familiar with both typical and atypical manifestations of renal lymphoma and should recommend imaging-guided percutaneous biopsy for diagnostic confirmation to avoid unnecessary nephrectomy.