Renal Dysfunction in Patients With Direct Infiltration by B-Cell Lymphoma

A Case of Extranodal NK/T-cell Lymphoma Infiltrating Kidneys, Presenting With Hematuria and Proteinuria With False-Positive Serum Anti-proteinase 3, and Mimicking Granulomatosis With Polyangiitis

We report a case of misdiagnosed extranodal NK/T-cell lymphoma, nasal type, mimicking granulomatosis with polyangiitis (GPA). A 30-year-old male presented with chronic non-resolving right paranasal sinusitis for two years accompanied by multiple generalized cutaneous nodules, and subnephrotic-range proteinuria. Biopsies from skin lesions and paranasal sinuses demonstrated leukocytoclastic vasculitis and necrotizing granulomatous inflammation, respectively. Serum proteinase 3 (PR3)-antineutrophilic cytoplasmic antibody (ANCA) was positive, suggesting the diagnosis of GPA based on the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for GPA. A kidney biopsy was not pursued due to the cause of glomerulonephritis (GN) being clinically evident, per the KDIGO 2021 GN Clinical Practice Guidelines. Immunosuppression was administered, which led to a transient improvement in clinical symptoms. However, subsequent kidney biopsy and other organ biopsies with cytogenic and molecular tests eventually confirmed extranodal NK/T-cell lymphoma infiltrating kidneys, skin, and paranasal sinuses. Physicians should always consider the possibility of hematologic malignancy in young adults presenting with multiple-organ involvement with vasculitic lesions or pauci-immune crescentic GN, albeit positive ANCA serologies. Kidney biopsy with cytogenic support should be performed to exclude threatening diseases, especially in atypical cases such as in young patients despite a context of compatible manifestations with other syndromes.

Case report: Acute kidney injury as the initial manifestation of chronic lymphocytic leukemia/small lymphocytic lymphoma

Chronic lymphocytic leukemia (CLL) is a lymphoproliferative disorder often diagnosed after incidental finding of leukocytosis. Renal involvement is usually clinically silent. Symptomatic renal impairment due to CLL/small lymphocytic lymphoma (SLL) cell infiltration in the kidney tissue is uncommon, and acute kidney injury (AKI) as a presenting feature is rare. In this case report, we describe the case of a patient with AKI caused by CLL/SLL infiltration as a presenting feature. Our report highlights the possibility of kidney injury as the first evident symptom of CLL/SLL. Kidney biopsy is the mainstay in these cases in order to establish a diagnosis. Treatment with zanubrutinib resulted in improved kidney function.

Primary lymphoma of the kidney: Pathology experience from 2 tertiary hospitals in Western Saudi Arabia

OBJECTIVES

To document the clinicopathological features of primary renal lymphoma (PRL) at 2 tertiary hospitals in the western region of the Kingdom of Saudi Arabia.

METHODS

Data were retrieved from all PRLs that were diagnosed at King Abdulaziz University Hospital and King Faisal Specialist Hospital and Research Centre, Jeddah, Saudi Arabia, between January 2002 and April 2022. Histopathological and immunohistochemical slides were reviewed, and additional immunohistochemistry stains were carried out in selected cases. Follow-up data were also collected.

RESULTS

There were 17 identified cases of PRL. The age of the patients ranged from 4-76 years (median: 50.5 years and mean: 46.8 years), 11 (64.7%) were males, and 6 (35.3%) were females. There were 12 cases of diffuse large B-cell lymphoma, 3 cases of Burkitt's lymphoma, and 2 cases of post-transplant lymphoproliferative disorder. The median follow-up duration was 22 months. The one-year overall survival rate was 71% and the 2-year overall survival rate was 43% during follow-up.

CONCLUSION

Primary renal lymphomas in Saudi patients are more common in males and seen in a relatively younger age group compared to the available worldwide data. The diagnosis of PRL is important to avoid tumor dissemination and unnecessary nephrectomy. Diffuse large B-cell lymphoma is the most common pathological type and non-germinal center B-cell is the most common subtype.

Histological Findings in Kidney Biopsies of Patients with Monoclonal Gammopathy—Always a Surprise

Background: The simultaneous occurrence of impaired kidney function and paraproteinemia is common in our constantly aging society. Both can be independent entities; however, renal insufficiency can also be caused by the paraprotein. We assessed all kidney biopsies in patients with monoclonal gammopathy in our clinic over the past 20 years and evaluated the histological results. Methods: Biopsies were systematically performed in nearly all patients with paraproteinemia and impaired kidney function (n = 178). The histological findings were systematically evaluated and correlated with the initial clinical diagnosis. Results: We found cast nephropathy (CN) in n = 66 (37.1%) biopsies, AL amyloidosis in n = 31 (17.4%) biopsies, monoclonal immunoglobulin deposition disease (MIDD) in n = 7 (3.9%) biopsies and other renal diseases (ORDs) in n = 74 (41.6%) biopsies. In the latter group, paraprotein-associated changes were found in 37 of 74 (50%) patients, whereas paraprotein-independent changes were found in the other half. Whereas, in the group of patients with MGUS, the findings were heterogenous, most of the patients with known multiple myeloma (MM) or B-NHL showed malignancy-associated changes in the kidney. The biopsy changed the diagnoses in a significant proportion of the patients: The group of patients with MM grew from 71 to 112 patients, whereas, in the MGUS group, only 31 of 44 patients remained. Conclusion: Kidney biopsies in patients with paraproteinemia and renal impairment show a wide range of findings that can lead to a change in diagnosis.

Complications of lymphoma in the abdomen and pelvis: clinical and imaging review

Involvement of the abdomen and pelvis is common in lymphoma. Nodal and extranodal abdominal and pelvic lymphoma may present with various complications. Complications are most common in high-grade lymphomas, especially diffuse large B-cell lymphoma. Complications may occur as the initial manifestation of lymphoma, during treatment course, or late following complete disease remission. Most complications are associated with worse prognosis and increased mortality. Imaging is essential in evaluation of disease extent and diagnosis of complications. Therefore, radiologists should be familiar with the clinical context and imaging features of abdominal and pelvic lymphoma complications. We provide a comprehensive, organ system-based approach, and clinical and imaging review of complications of abdominal and pelvic lymphoma along with radiologic images of illustrated cases of the most commonly encountered complications.

Renal lymphoma diagnosed on kidney biopsy presenting as acute kidney injury

Introduction:

Renal manifestations associated with hematolymphoid malignancies are known. Primary or secondary involvement of the kidney by lymphomatous infiltration has various clinical presentations. Acute kidney injury is not an uncommon finding in relation to lymphomatous interstitial infiltration proven on kidney biopsy. However, diagnosing it solely on renal biopsy remains a challenge and needs expertise and aid of immunohistochemistry as the prognosis is dismal.

Methods:

This is a retrospective study of kidney biopsy-proven cases of renal lymphoma presenting with acute kidney injury.

Results:

The study included 12 patients with ages ranging from 4 to 50 years who presented with serum creatinine ranging 2.1–9.6 mg%. Renal biopsy findings showed interstitial lymphomatous infiltrate. Two cases were diagnosed as primary lymphoma and the other 10 as secondary lymphomas. Among the 12 cases, nine were B-cell non-Hodgkin lymphoma, of which diffuse large B-cell lymphoma was diagnosed in six (50%), low-grade B-cell type in two (16.6%), chronic lymphocytic leukemia in one (8.3%), and three were T-cell-type. Two were acute T-cell lymphoblastic lymphoma and one other was a high-grade T-cell lymphoma. Four patients succumbed. The other four patients are alive; one is on chemotherapy, while two of them are on hemodialysis.

Conclusion:

Acute kidney injury as a presenting feature with lymphomatous infiltration of renal parenchyma is not uncommon. The patchy involvement makes it challenging on kidney biopsy with definitive diagnosis being made with the help of immunohistochemistry. Appropriate multidisciplinary involvement improves patient outcome.

Aetiology, course and treatment of acute tubulointerstitial nephritis in paediatric patients: a cross-sectional web-based survey

BACKGROUND

Acute tubulointerstitial nephritis (TIN) is a significant cause of acute renal failure in paediatric and adult patients. There are no large paediatric series focusing on the aetiology, treatment and courses of acute TIN.

PATIENTS, DESIGN AND SETTING

We collected retrospective clinical data from paediatric patients with acute biopsy-proven TIN by means of an online survey. Members of four professional societies were invited to participate.

RESULTS

Thirty-nine physicians from 18 countries responded. 171 patients with acute TIN were included (54% female, median age 12 years). The most frequent causes were tubulointerstitial nephritis and uveitis syndrome in 31% and drug-induced TIN in 30% (the majority of these caused by non-steroidal anti-inflammatory drugs). In 28% of patients, no initiating noxae were identified (idiopathic TIN). Median estimated glomerular filtration rate (eGFR) rose significantly from 31 at time of renal biopsy to 86 mL/min/1.73 m² 3-6 months later (p<0.001). After 3-6 months, eGFR normalised in 41% of patients (eGFR ≥90 mL/min/1.73 m²), with only 3% having severe or end-stage impairment of renal function (<30 mL/min/1.73 m²). 80% of patients received corticosteroid therapy. Median eGFR after 3-6 months did not differ between steroid-treated and steroid-untreated patients. Other immunosuppressants were used in 18% (n=31) of patients, 21 of whom received mycophenolate mofetil.

CONCLUSIONS

Despite different aetiologies, acute paediatric TIN had a favourable outcome overall with 88% of patients showing no or mild impairment of eGFR after 3-6 months. Prospective randomised controlled trials are needed to evaluate the efficacy of glucocorticoid treatment in paediatric patients with acute TIN.

Morphological and Molecular Study of Hybrid Oncocytic/Chromophobe Tumor of the Kidney Associated with Sporadic Renal Oncocytosis and Chronic B-Cell Lymphocytic Leukemia: The Possible Contribution of Lymphoma to Renal Oncocytosis

Hybrid oncocytic/chromophobe tumor (HOCT) of the kidney arising from a precursor oncocytosis not associated with the Birt-Hogg-Dubé (BHD) syndrome is an unusual and highly interesting neoplasm. Immunohistochemical and molecular findings suggest that HOCT is an entity distinct from both oncocytoma and chromophobe carcinoma. Although uncertainty persists regarding the factors predisposing to the development of HOCT, experimental findings suggest that it may arise due to the effect of toxins or in association with chronic kidney failure. The potential role of prior renal lymphoma in the development of oncocytosis has not hitherto been examined. We present a morphological, immunohistochemical, and molecular analysis of an HOCT arising from renal oncocytosis in conjunction with CLL affecting the kidney. The findings suggest that this tumor belongs to a family of similar neoplasms including oncocytoma, the eosinophilic variant of chromophobe renal-cell carcinoma (CRCC), and low-grade oncocytic tumor, even though these neoplasms may arise from different precursor lesions. HOCT and oncocytosis revealed the same immunohistochemical profile consistent on positivity for epithelial membrane antigen (EMA), cytokeratin 7 (Ck7), E-cadherin, CAM 5.2 and negativity for Pax-8, vimentin, renal-cell carcinoma (RCC) antigen, CD117, racemase, progesterone receptor, and CD10. The Ki-67 proliferation index was <1%. Molecular analysis of the tumor revealed the AKT3 gene mutation variant, classified as probably pathogenic, together with FOS1 gene amplification and no copy number variations (CNVs). Finally, we present a case of HOCT arising from a nonhereditary renal oncocytosis in conjunction with B lymphoma that raises interesting questions regarding pathogenesis.

IgA Nephropathy with Dominant IgA2 Deposition Accompanied by Mantle Cell Lymphoma

Malignant lymphoma is rarely complicated by secondary IgA nephropathy. We encountered a 74-year-old man with rapidly progressive glomerulonephritis due to IgA nephropathy with predominant deposition of IgA2, instead of IgA1, in the glomerulus that was eventually diagnosed as secondary IgA nephropathy due to mantle cell lymphoma. Renal impairment was improved by chemotherapy for the mantle cell lymphoma. IgA came from the colonic mucosa that was stimulated by the infiltrated lymphoma cells, instead of the tumor itself. We should consider mantle cell lymphoma as a cause of secondary IgA nephropathy, although its prevalence may not be very high.

Renal Diseases Associated with Hematologic Malignancies and Thymoma in the Absence of Renal Monoclonal Immunoglobulin Deposits

In addition to kidney diseases characterized by the precipitation and deposition of overproduced monoclonal immunoglobulin and kidney damage due to chemotherapy agents, a broad spectrum of renal lesions may be found in patients with hematologic malignancies. Glomerular diseases, in the form of paraneoplastic glomerulopathies and acute kidney injury with various degrees of proteinuria due to specific lymphomatous interstitial and/or glomerular infiltration, are two major renal complications observed in the lymphoid disorder setting. However, other hematologic neoplasms, including chronic lymphocytic leukemia, thymoma, myeloproliferative disorders, Castleman disease and hemophagocytic syndrome, have also been associated with the development of kidney lesions. These renal disorders require prompt recognition by the clinician, due to the need to implement specific treatment, depending on the chemotherapy regimen, to decrease the risk of subsequent chronic kidney disease. In the context of renal disease related to hematologic malignancies, renal biopsy remains crucial for accurate pathological diagnosis, with the aim of optimizing medical care for these patients. In this review, we provide an update on the epidemiology, clinical presentation, pathophysiological processes and diagnostic strategy for kidney diseases associated with hematologic malignancies outside the spectrum of monoclonal gammopathy of renal significance.

Clinicopathological features of Chinese patients with B-cell lymphoproliferative disorders and kidney infiltration

AIM

Direct kidney involvement in B-cell lymphoproliferative disease is a rare disorder with only a few studies reported in Caucasian patients. The clinicopathological characteristics and outcome of this entity remain poorly described.

METHODS

We retrospectively studied all adult Chinese patients who had histology-proven renal parenchymal infiltration by malignant B-cells between 1 January 2000 and 31 December 2018 at two tertiary hospitals in Hong Kong. Clinical, pathological and radiological data were collected from 20 patients. Follow-up data were analysed until 31 December 2019.

RESULTS

Median follow-up duration was 22 (1-171) months. Only seven patients (35%) had established diagnosis of haematological cancer before kidney biopsy. Diffuse large B-cell lymphoma (DLBCL) was the most common subtype in our cohort (n = 5, 25%). Others included low-grade B-cell lymphoma (n = 11), intravascular large B-cell lymphoma (n = 1), mantle cell lymphoma (n = 1) and multiple myeloma (n = 2). Fourteen patients (70%) presented with AKI while 12 patients (60%) had proteinuria. Seven patients (35%) had unilateral renal mass, one had bilateral renal masses and one had bilateral diffuse nephromegaly in computed tomography. Lymphomatous tubulointerstitial infiltration was the prevalent histological finding. Nine patients (45%) had coexisting renal lesions other than direct tumour infiltration. All but one patient received chemotherapy. Ten patients died and renal responders had a significantly better survival than non-renal responders (p = .03).

CONCLUSION

Direct tumour infiltration can occur in a wide variety of B-cell lymphoproliferative disorders. Coexisting immunoglobulin-related nephropathy is frequently found. Renal biopsy is required for early diagnosis which allows timely and appropriate treatment.