Primary renal lymphoma: a comprehensive review of the pathophysiology, clinical presentation, imaging features, management and prognosis

Fibrin-Associated Large B-Cell Lymphoma (FA-LBCL) Involving Solid Organs as Necrotic Cystic Lesions-A Rare Entity with Potential Diagnostic Pitfalls: A Two-Case Series and Review of the Literature

Fibrin-associated large B-cell lymphoma (FA-LBCL) is a rare subtype of Epstein-Barr virus (EBV)-associated lymphoma, recognized as an independent entity per the 5th edition of the WHO classification of hematolymphoid neoplasms. It is usually associated with longstanding chronic inflammation and arises within fibrinous material in confined anatomic spaces. We report the clinicopathologic manifestations of two patients of FA-LBCL involving the adrenal gland and kidney. Both tumors were diagnosed after presenting as cystic masses on imaging studies. These lymphomas were non-invasive, with microscopic aggregates of large B-lymphoma cells along/within cystic wall and admixed with fibrinous material and without prominent inflammation. By immunohistochemistry and in-situ hybridization, lymphoma cells were positive for CD45, PAX5, CD79a, MUM1, BCL2, PD-L1, and EBV/EBER (Epstein-Barr virus encoded small RNA) with a high proliferation index. Both patients remain in remission after management with complete surgical resection and additional chemo-immunotherapy in one patient. Considering its rarity, scant tumor cells, and varied clinical presentations, FA-LBCL may pose diagnostic challenges, especially when presenting as extensively necrotic cystic lesions, needing multidisciplinary collaboration in formulating management.

Large renal lymphoma in a patient with horseshoe kidney: A case report

Horseshoe kidney (HSK) is the most common renal fusion anomaly. It frequently consists of kidney fusion in the lower pole across the midline and occurs during embryogenesis. The incidence of malignancies in HSKs can be 3-4 times higher than that in normal kidneys. A 69-year-old man with a voluminous right kidney neoplasm in HSK and a single omolateral axillary lymphadenopathy underwent complete excision of right axillary lymphadenopathy and ultrasound-guided percutaneous biopsy of the right kidney expansive lesion. The diagnosis of non-Hodgkin's B cell lymphoma both in HSK and right axilla was made. We report this case to raise awareness among physicians regarding the importance of a correct clinical evaluation and diagnostic workup so as to avoid surgery, which is not easy and without complications, in patients with this kidney anomaly. Primary renal lymphoma should also be included among possible neoplasms of HSK. Renal biopsy should always be recommended in cases where atypical findings are obtained from imaging techniques and when its outcome can impact clinical decision-making. In the present case, biopsy was performed, and thus, nephrectomy was avoided and specific medical therapy was quickly started.

A rare primary renal lymphoma with liver infiltration: A case report and literature review

Primary extra-nodal of Non-Hodgkin Lymphomas (NHL) are rare, and one of the very rare primary loci is renal, namely Primary renal lymphoma (PRL), which is about 0,1-0,7%, and the mortality rate reaches as high as 75%. Here, the author shares a 58-year-old man with an imaging test indicating a mass from the upper pole of the right renal with a sixth segment of the liver infiltration. The patient underwent multidisciplinary embolization and nephrectomy. Histopathologic show the anaplastic lymphoid cells in the kidney and the hepar and lead to chemotherapy with a CHOP regimen for six cycles.

Pediatric primary renal lymphoma presenting with multiple masses: A challenging case report and narrative review

RATIONALE

Only 20 cases of pediatric primary renal non-Hodgkin's lymphoma have been reported since 1995, rare cases and a variety of imaging manifestations have led to difficulties in its diagnosis and treatment.

PATIENT CONCERNS

Herein, we share in detail a case of primary renal lymphoma (PRL) in a child and summarize the common clinical manifestations, imaging features, and prognostic factors of pediatric PRL by retrospectively analyzing cases reported in the literature. A 2-year-old boy presented to the clinic with a large mass on the right side of his abdomen along with loss of appetite.

DIAGNOSES

Imaging revealed a large right renal mass, nearly replacing the entire renal tissue, along with numerous small nodules in the left kidney. Given no local adenopathy and metastases, the diagnosis was unclear. A percutaneous renal puncture was performed, which proved the diagnosis of Burkitt's lymphoma. Since no bone marrow involvement, this child was diagnosed with pediatric PRL.

INTERVENTIONS

This PRL boy was treated with the NHL-BFM95 protocol and supportive care.

OUTCOMES

Unfortunately, this boy died of multiple organ failure in the fifth month of treatment.

LESSONS

As per literature review, the presentation of pediatric PRL is fatigue, loss of appetite, weight loss, abdominal swelling, or other nonspecific symptoms. Although in 81% of cases it often infiltrates the bilateral kidneys, urine abnormalities caused by pediatric PRL are uncommon. 76.2% of pediatric PRL were boys and 2/3 of all cases presented as diffuse renal enlargement. Those PRL presented as masses could easily be misdiagnosed as WT or other malignancies. Absent of local enlarged lymph node, no necrosis or calcification suggest atypical presentation of renal masses and a percutaneous biopsy is needed in timely establishing the accurate diagnosis for appropriate treatment. Based on our experience, percutaneous renal puncture core biopsy is a safe procedure.

The Role of CT Imaging in Characterization of Small Renal Masses

Small renal masses (SRM) are increasingly detected incidentally during imaging. They vary widely in histology and aggressiveness, and include benign renal tumors and renal cell carcinomas that can be either indolent or aggressive. Imaging plays a key role in the characterization of these small renal masses. While a confident diagnosis can be made in many cases, some renal masses are indeterminate at imaging and can present as diagnostic dilemmas for both the radiologists and the referring clinicians. This review focuses on CT characterization of small renal masses, perhaps helping us understand small renal masses. The following aspects were considered for the review: (a) assessing the presence of fat, (b) assessing the enhancement, (c) differentiating renal tumor subtype, and (d) identifying valuable CT signs.

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.