Malignant lymphoma presenting as a renal mass: four cases

Area of Science:

• Nephrology
• Oncology
• Pathology

Background:

• Primary renal lymphoma is exceptionally rare.
• Renal masses are typically associated with adjacent disease spread or systemic lymphoma.

Observation:

• Four patients (3 male, 1 female, aged 45-71) presented with solitary renal masses mimicking renal cell carcinoma.
• Symptoms included abdominal pain, hematuria, and "B" symptoms; physical exams showed no peripheral lymphadenopathy or hepatosplenomegaly.
• Elevated lactate dehydrogenase (LDH) and mild increases in blood urea nitrogen (BUN) and creatinine were noted.

Findings:

• Two cases were accurately diagnosed via needle biopsy, confirmed by ultrastructural studies, marker analysis, DNA flow cytometry, and cytogenetics.
• Histological subtypes included three large-cell lymphomas and one small noncleaved cell lymphoma.
• Two patients underwent nephrectomy due to a presumed renal cell carcinoma diagnosis.

Implications:

• Highlights the diagnostic challenge of primary renal lymphoma.
• Emphasizes the importance of accurate pre-operative diagnosis through biopsy.
• Timely diagnosis can prevent misdiagnosis and inappropriate surgical intervention such as nephrectomy.