Summary: A 53-year-old woman presents for surveillance
imaging. Numerous hypodense renal masses were detected.
Bilateral renal lymphoma
A computed tomography (CT) exam showed the kidneys were enlarged. Numerous hypodense renal masses are seen
bilaterally, measuring up to 3 cm in the upper pole of the right kidney.
Retroperitoneal lymphadenopathy is partially visualized.
Clinical history is imperative in
the differential diagnosis of multiple bilateral renal masses. This patient had
a known history of nonHodgkin lymphoma (follicular lymphoma) with extensive
lymphadenopathy within the chest, abdomen, and pelvis. Follow-up imaging after
chemotherapy demonstrated resolution of bilateral solid renal masses.
Renal lymphoma is usually a secondary manifestation of systemic disease. Primary
renal lymphoma is thought to be rare.4 Renal lymphoma may present as
a variety of imaging findings. These findings include solitary renal mass,
multiple renal masses, perinephric soft-tissue mass, diffuse renal
infiltration, direct extension from retroperitoneal lymphadenopathy, and/or
enlargement of the kidneys.4 The most common presentation is
multiple renal masses, seen in 50% to 60% of cases, which may be unilateral or
bilateral.4 Involvement of the kidneys by nonHodgkin lymphoma is
seen in about 3-8% of patients by imaging; however, on autopsy, the frequency
of involvement increases to around 38%.3 Patients with renal
lymphoma are generally asymptomatic with normal renal function maintained.3
Renal cell carcinoma tends to have a more heterogeneous appearance than renal lymphoma.
2 Although bilateral renal cell carcinoma is uncommon, this may be seen
in patients with syndromes such as von Hippel Lindau. 2 Associated
tumor invasion of the renal vein with possible extension into the inferior vena
cava (IVC) would suggest renal cell carcinoma over other diagnoses. 1
In patients with a known primary malignancy, metastatic disease should be
considered in the differential diagnosis. Breast cancer, lung cancer, gastric
cancer, melanoma and other malignancies may metastasize to the kidneys and
present as renal masses.3
Lastly, pyelonephritis may have a variety of imaging appearances. Diagnosis can be confirmed by
clinical history and urinalysis. In patients with a complicated history,
follow-up imaging to document resolution may be helpful.1
- Urban BA, Fishman EA. Renal lymphoma: CT patterns with emphasis on helical CT.
- Sheth S, Ali S, Fishman E.
Imaging of renal lymphoma: Patterns
of disease with pathologic correlation. Radiographics. 2006;26:1151-1168.
- Sheeran S, Sussman S.
Renal lymphoma: Spectrum of CT
findings and potential mimics. AJR
- Dunnick NR, Sandler CM,
Newhouse JH, Amis ES. Textbook of uroradiology, 4th ed. Philadelphia, PA: Lippincott Williams
& Wilkins; 2007.