Primary mucosa-associated lymphoid tissue-type lymphoma arising in the kidney

A case of perirenal non-specific lymphadenitis mimicking a solitary renal mass

INTRODUCTION

Since the diagnosis of small renal masses is often a challenge despite improvements in imaging modalities, renal tumor biopsy provides useful information regarding treatment decisions. However, there is no established treatment strategy when renal biopsy shows lymphoid tissue.

CASE PRESENTATION

A 63-year-old woman was referred to our department for the investigation of a small renal mass. Contrast-enhanced computed tomography showed a weakly enhancing mass 39 × 17 mm in diameter in the left kidney. A renal tumor biopsy was performed, and histopathological examination showed lymphoid tissue, but the diagnosis was not confirmed. The tumor was bluntly dissected from the renal capsule via robotic-assisted laparoscopic surgery without renal artery clamping. The pathological diagnosis was non-specific lymphadenitis.

CONCLUSION

We report a rare case of perirenal non-specific lymphadenitis mimicking a solitary renal mass. Non-specific lymphadenitis is a possible differential diagnosis of renal masses.

Mucosa-Associated Lymphoid Tissue Lymphoma Involving the Kidney and Renal Pelvis

Mucosa-associated lymphoid tissue (MALT) lymphomas are a distinctive group of B-cell lymphomas. These lymphomas arise from various anatomic sites and are mainly seen in the gastrointestinal tract, but the primary involvement of the kidney is extremely rare. We report a case of a MALT lymphoma involving the kidney and the renal pelvis. A 56-year-old man presented with a history of hematuria and left flank pain. A computed tomography scan showed a marked tissue densification in the renal sinus, suggesting marked thickening of the urothelium, conditioning deformity of the renal pelvis and calyces. A cystoscopy confirmed a 2-cm papillary lesion on the left lateral aspect of the bladder. The patient underwent laparoscopic radical nephoureterectomy and transurethral bladder resection. The pathological diagnosis was MALT lymphoma in the kidney and urothelial carcinoma of the bladder. The patient was referred to a hematologist and was free of disease at 20 months of follow up without additional treatment.

The Differential Diagnosis of Medullary-Based Renal Masses

CONTEXT.—

Renal malignancies can be divided into cortical- and medullary-based tumors, the latter of which classically infiltrate the renal parenchyma by extending between nonneoplastic structures. Although high-grade cortical tumors can rarely exhibit the same growth pattern, the infiltrative morphology should elicit a differential diagnosis to be considered in each case. However, these diagnoses can be challenging to distinguish, especially on small renal biopsy samples.

OBJECTIVE.—

To provide an overview of the clinical, gross, and microscopic findings; genetic and molecular alterations; and immunohistochemical evaluation of medullary-based renal tumors and other tumor types with overlapping morphologies and growth patterns.

DATA SOURCES.—

Literature review and personal observations were used to compile the information in this review.

CONCLUSIONS.—

Collecting duct carcinoma is a prototypical medullary-based tumor, and although diagnostic criteria exist, it remains a diagnosis of exclusion, especially with ancillary techniques aiding the recognition of established as well as more recently described neoplasms. Other medullary-based malignancies included in the differential diagnosis include renal medullary carcinoma/renal cell carcinoma unclassified with medullary phenotype, fumarate hydratase-deficient renal cell carcinoma, and upper tract urothelial carcinoma. Moreover, other rare entities should be excluded, including metastatic carcinoma, lymphoma, and melanoma. In addition to potential prognostic differences, accurate diagnoses can have important surgical and clinical management implications.

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.

Primary renal MALToma: A rare differential diagnosis for a recurrent renal mass after primary ablative therapy

We report a case of primary renal lymphoma of mucosa-associated lymphoid tissue in an 82-year-old woman. She presented with a history of renal mass previously treated with kidney percutaneous cryoablation at another centre.

Mucosa-associated lymphoid tissue lymphoma arising from the kidney

Primary renal lymphoma is rare, and most are intermediate- and high-grade lymphomas of B-cell lineage, such as diffuse large B-cell or Burkitt lymphoma. We report a case of low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) arising from the kidney. Only a few cases of primary renal MALT lymphoma have been published.

Malignant lymphoma of mucosa-associated lymphoid tissue involving the renal pelvis and the entire ureter: A case report

Mucosa-associated lymphoid tissue (MALT) lymphoma occurs in various sites, but rarely in the urinary tract. Imaging studies of a 69-year-old male revealed a left hydronephrosis and diffuse thickening of the renal pelvic and upper ureteral wall. Retrograde pyelography revealed a narrowing in this region, and brush cytology specimens contained atypical cells. As the lesion was considered to be malignant, surgical excision was performed. Histological analysis revealed an intense lymphoid infiltrate mainly consisting of B cells. The immunohistochemistry results demonstrated that the lesion was positive for CD20 and CD79a and negative for CD5 and cyclin D1. These findings led to a diagnosis of MALT lymphoma. Pathological exploration disclosed a focally dense invasion of lymphoma cells into not only the renal pelvis, but the whole ureteral wall and surrounding tissue; therefore, the patient underwent eight courses of rituximab treatment. Diffuse invasion of lymphoma cells into the whole ureter was rarely observed. Since the surgery, the patient has survived for 78 months without evidence of a recurrence of lymphoma.

Renal MALT lymphoma associated with Waldenström macroglobulinemia

Mucosa associated lymphoid tissue lymphoma (MALT lymphoma) is mostly seen in the gastrointestinal tract; origin from the kidney is extremely rare. Waldenström macroglobulinemia (WM) is a clinicopathologic syndrome denoted by the presence of monoclonal gammopathy in the serum, typically caused by lymphoproliferative disorder. Literature review did not find any report of renal MALT lymphoma accompanied by WM. Herein, for the first time, we report a 72 year-old female patient with a history of chronic kidney disease, presenting with solitary renal mass; MALT lymphoma was confirmed by pathological examination. A serology study identified the presence of WM. No manifestation of hyperviscosity syndrome was noted. Bone marrow biopsy disclosed the concurrent systemic involvement. Her treatment response was uneventful and the renal mass responded with regressive change in size after chemotherapy. The renal function remained stable during follow-up. MALT lymphoma should be considered as an underlying pathology of isolated renal mass. Furthermore, patients with MALT lymphoma should be screened for Waldenström macroglobulinemia and hyperviscosity syndrome.