AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Background

Lymphoma of the kidneys is diagnosed at the time of autopsy in almost one half of cases. It is rarely suspected on conventional urologic studies, such as intravenous urography. However, renal involvement with lymphoma is commonly discovered in patients with known lymphoma, who may be diagnosed, staged, or followed by cross-sectional imaging, such as computed tomography (CT) scanning or magnetic resonance imaging (MRI).

Pathophysiology

Familiarity with tumoral growth and the mechanism of lymphoma spread is crucial to understanding the resultant imaging patterns of organ involvement. Renal lymphoma is often a secondary process that is discovered in patients with known lymphoma.

Hematogenous involvement of the kidneys usually results in a bilateral distribution of the tumor foci within the renal cortex. Tumor proliferation begins in the interstitium and the underlying nephrons; however, collecting systems and blood vessels provide a framework for tumor growth. Infiltrative growth results in preservation of the parenchymal structures and renal contour; consequently, detection is often difficult, and renal involvement can be easily missed. As lymphomatous tumors enlarge, the surrounding renal parenchyma is compressed and destroyed, and continuous tumor infiltration results in the formation of expansile renal masses. Nonuniform growth can result in single or conglomerate masses that extend beyond the renal contour and displace the collecting system; thus, when there is a single mass, it can resemble primary renal neoplasms.

Buyukpamukçu et al studied 104 pediatric patients with renal involvement from non-Hodgkin lymphoma.¹ A renal infiltration pattern was reported to be nodular in 62 children (59.6%) and diffuse in 40 others (38.5%). Two patients had tumoral masses of renal origin (1.9%). Seventy-five children had bilateral renal involvement (72.1%), and 29 had unilateral involvement. The overall survival rate was 42.5% (median follow-up of 64 mo).

The mechanism of development of primary renal lymphoma is unclear, and this condition as a clinical entity has been disputed because the kidneys reportedly do not contain lymphatic tissue.^{2, 3, 4} Most of the few reported cases of primary renal lymphoma showed rapid systemic progression and a poor prognosis. Nevertheless, primary lymphoma of the kidneys represents a rare entity which must be considered in cases of unusual renal masses or otherwise unexplained renal symptoms.³

Frequency

International

The incidence of renal involvement in patients with lymphoma has been reported to be 34-62% in several autopsy case series. However, there is no agreement whether or not renal involvement is an initial manifestation of a rapidly systemic disease. In addition, most of the reported cases are of questionable validity because of incomplete staging and the lack of autopsy studies.⁴

Renal involvement occurs more commonly in non-Hodgkin lymphoma than in Hodgkin lymphoma. The incidence rate is often underestimated in imaging studies, with CT scanning depicting renal involvement in up to 8% of all patients undergoing routine CT scanning for the staging of lymphoma. In part, this discrepancy reflects the fact that patients with presumed lymphomatous renal involvement rarely undergo nephrectomy or biopsy. The disease process is silent and often poorly documented.

Mortality/Morbidity

• Because involvement of the kidneys usually indicates disseminated disease, in the absence of proper clinical treatment, the prognosis is poor. The disease may present with progressive renal failure of either the oliguric or nonoliguric type. In primary renal lymphoma, survival is extremely poor: 75% of patients die in less than 1 year. The prognosis may be improved by early detection of the disease and by performing systemic chemotherapy.
• With appropriate treatment, renal lesions may completely regress, often with minimal scarring within the renal parenchyma (see Images 1-2).

Race

Renal lymphoma demonstrates no racial predilection.

Sex

Renal lymphoma demonstrates no sex predilection. However, it is reportedly seen more often in male patients.

Age

Renal lymphoma occurs in all age groups. The disease usually affects adults (average age: 60 y); however, renal lymphoma has also been reported in childhood. 

Anatomy

The kidneys are bean-shaped structures that are located in the retroperitoneal region and surrounded by the Gerota fascia. The renal parenchyma is enclosed in a thin, fibrous, glistening membrane that represents a true capsule. The lateral edge of the kidneys is convex, whereas the medial border is concave, with a marked depression or notch, termed the hilus. In adults, each kidney weighs 120-170 g and is approximately 11 cm long, 2.5 cm thick, and 5 cm wide.

Usually, the left kidney is approximately 1.5 cm higher than the right kidney. When the patient is lying in the supine position, the superior pole of the left kidney is at the level of the 12th thoracic vertebra, and the inferior pole is at the level of the 3rd lumbar vertebra. With a patient in the erect position or during deep inspiration, both kidneys may descend as low as near the iliac crest or even lower.

As a result of the proximity of the kidneys to the psoas muscles, the oblique course of these muscles causes slight lateral displacement of the lower pole of each kidney. Between the 2 kidneys are the aorta and inferior vena cava, as well as the celiac plexus and the ganglia of the autonomic nervous system. The renal artery and vein anterior to the renal pelvis run medially and anteriorly from the hilus of each kidney. The kidneys are usually supplied by one renal artery each; however, it is not uncommon to see 2 or more renal arteries originate from the aorta. Although the left renal vein normally courses anterior to the aorta to drain into the vena cava, this vein can occasionally run behind the aorta (retroaortic renal vein) or be anterior and posterior (circumaortic) to the aorta.

Clinical Details

Patients with renal lymphoma may not be symptomatic; however, renal function laboratory studies occasionally reveal elevated blood urea nitrogen and creatinine levels, which may suggest an obstruction. Therefore, the patient may need to undergo radiologic evaluation.

Sometimes, patients present with nonspecific signs and symptoms, including flank pain, weight loss, hematuria, or a palpable mass. Occasionally, symptoms of back pain are attributed to the patient's known underlying lymphoma. The nature of lymphomatous infiltration around the renal pedicle is such that it may not cause vascular compromise; however, the tumor usually surrounds the renal vascular pedicle, and the tumor mass can obstruct urine flow, resulting in hydronephrosis.

Preferred Examination

Numerous diagnostic studies are available for the evaluation of renal involvement from lymphoma, including intravenous urography, ultrasonography, nuclear medicine, MRI, and CT scanning. Although each technique may provide useful information in the detection, characterization, and staging of the disease, CT scanning remains the most sensitive, efficient, and comprehensive modality.

Urography provides information regarding involvement of the collecting system, the functional status of the kidneys, and the severity of hydronephrosis. Ultrasonography is a good screening examination, particularly for the assessment and follow-up of patients with hydronephrosis. In comparison, nuclear medicine studies, particularly those that use gallium-67 citrate, have a higher degree of specificity in the detection of lymphomatous infiltration of the kidneys. MRI provides information for characterizing the lesion, and it is also helpful in assessing the renal vascular pedicle.

CT scanning is the diagnostic modality of choice in patients with suspected renal masses (see Images 1-6). CT scans depict renal involvement in most patients with lymphoma, often help in defining the extent of disease within and outside of the kidneys, and provide information for staging of the patient's underlying malignancy. In addition, the result of treatment can be assessed on follow-up CT scans. The CT scan examination must be done with intravenous contrast media. Therefore, if contrast media cannot be used in patients for reasons such as renal failure or allergy to iodine, MRI then becomes the diagnostic modality of choice.

Limitations of Techniques

Intravenous urography can depict only the renal collecting system and suggestive large masses that have caused calyceal distortion. Small parenchymal masses and tumors around the kidney and in the retroperitoneum are often not demonstrated with this diagnostic examination.

On sonograms, the parenchymal masses are often hypoechoic, reflecting tissue homogeneity, and they can be misidentified as renal cysts.

Regarding nuclear medicine studies, although gallium-67 citrate is an isotope that often accumulates in lymphomatous tissue, it can also be taken up by inflammatory masses.

Nonenhanced CT scan studies or MRIs can cause masses to be missed, particularly when such masses are small.

Patient Education: For excellent patient education resources, visit eMedicine's Cancer and Tumors Center. Also, see eMedicine's patient education article Renal Cell Cancer.

DIFFERENTIALS

Section 3 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Other Problems to Be Considered

Renal metastasis
Renal abscess

RADIOGRAPH

Section 4 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Plain radiographs are limited when compared with other available modalities such as CT scanning, ultrasonography, and MRI. Intravenous urography may show distortion of the collecting system as a result of a single or multiple renal masses. This finding cannot be differentiated from findings in simple cysts or renal cystic disease. However, intravenous urograms of renal lymphoma can demonstrate normal or near-normal findings (see Image 7).

Degree of Confidence

With urography, the degree of confidence for the diagnosis of renal lymphoma is low. If renal involvement is suggested on an intravenous urogram, contrast-enhanced CT scanning or MRI must be performed (see Image 8). If the urographic findings are considered normal but the clinical findings (eg, abnormal renal function) suggest renal involvement, a cross-sectional study is indicated.

False Positives/Negatives

In lymphomatous renal involvement, findings of an intravenous urogram can be normal and, therefore, falsely negative. With urography, a high rate of false-negative diagnoses is possible.

CT SCAN

Section 5 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

CT scans demonstrate a wide variety of appearances in renal lymphoma; the study patterns depend on the technique of CT scanning. Multidetector and spiral/helical CT scanning are universally accepted as the techniques of choice in patients with renal involvement, and they have a high degree of sensitivity in the detection of renal lymphoma.

Breath-hold images can be quickly obtained during the multiple phases of renal enhancement after the intravenous injection of contrast medium. The nephrographic phase is the most important phase for renal parenchymal assessment. These images are essentially free of motion artifact and respiratory misregistration. This approach helps in accurately detecting and characterizing most renal masses, including smaller lesions that may involve the renal parenchyma in lymphoma (see Image 8). In addition, the vascular phase of contrast enhancement enables characterization of the renal vasculature, which may be involved in renal cell carcinoma but uncommonly in renal lymphoma. Without intravenously administered contrast material, infiltrative forms of renal lymphoma can be entirely missed on CT scan studies. Also, CT scanning should not be limited to the cortical medullary phase of contrast enhancement because the lesions can be missed in this phase.

Typical imaging findings of renal lymphoma include multiple poorly enhancing masses, retroperitoneal tumors that directly invade the kidneys, a solitary mass, bilateral renal enlargement, and perirenal soft-tissue masses. Unless the renal lesions manifest in the setting of widespread lymphoma, percutaneous biopsy is indicated to differentiate lymphoma from metastases. Radiologists should be familiar with both the typical and atypical manifestations of renal lymphoma and should recommend imaging-guided percutaneous biopsy for diagnostic confirmation to avoid unnecessary nephrectomy.

Multiple renal masses are most common in patients with lymphoma (see Images 1-4 and 10). The masses are typically bilateral, but they may also be unilateral. Multiple masses are seen in approximately 60% of patients, and they reflect advanced disease in patients who present for staging evaluation. Depending on the size and expansile nature of individual neoplastic deposits, little mass effect on the renal contour may be seen. Therefore, although renal involvement may be extensive, imaging findings can be subtle, and intravenous contrast enhancement is essential. The masses range in size from a few millimeters to several centimeters and are seen as areas of low attenuation. Although the masses are often homogeneous on CT scans, they can be heterogeneous or low density, as well as mimic a complicated cyst. This is typically a sign of tumor necrosis in patients undergoing chemotherapy. In approximately 50%of patients, associated  retroperitoneal adenopathy is noted.

Solitary masses are reported in approximately 10-20% of patients (see Images 5-6 and 11-12). The mass can be as large as 15 cm and can cause significant distortion of the renal contour. Solitary lesions resemble other renal neoplasms that grow primarily by expansion, including renal cell carcinoma or isolated metastasis.

Continuous retroperitoneal extension into the kidney is a common pattern of renal involvement in lymphoma and is seen in approximately 30% of patients (see Images 12-13). Continuous extension typically results in a large, bulky retroperitoneal mass that envelops the renal vasculature and invades the renal hilus. In most patients, the renal vascular pedicle is patent and engulfed by the retroperitoneal mass. Continuous extension of retroperitoneal involvement in the renal collecting system can often cause obstruction, and patients commonly present with hydronephrosis.

Rarely, perirenal disease is seen in an isolated form without involvement of the renal parenchyma or retroperitoneal nodes (see Images 14-17). Occasionally, this feature is seen without compression of the renal parenchyma or functional impairment; such a finding is rare and virtually pathognomonic for perirenal lymphoma (see Image 18). A variety of CT scan manifestations of perirenal lymphoma, including renal sinus infiltration, thickening of the Gerota fascia, and perirenal masses, have been described. The normal renal parenchyma cannot be differentiated from the perirenal abnormality if intravenous contrast enhancement is not used in CT scanning (see Image 15).

Infiltrative disease is associated with lymphomatous proliferation within the interstitium of the kidney, which manifests as nephromegaly, with preservation of renal contour (see Image 19). Diffuse infiltration is often bilateral and is seen in approximately 20% of patients. The diagnosis is often subtle and depends on the finding of global renal enlargement. Usually, kidneys infiltrated by lymphoma have poor function, but the disease is often clinically silent.

Atypical manifestations of renal lymphomatous mass, such as spontaneous hemorrhage, necrosis, heterogeneous attenuation, cystic transformation, and calcifications, are occasionally depicted on CT scans. Often, these findings are the result of previous treatment for renal lymphoma. More commonly, the findings of renal lymphoma regress after chemotherapy, and the kidneys regain a normal CT scan appearance.

In patients who are immunocompromised, the prevalence of lymphoma is increased. Lymphoma typically occurs in patients with human immunodeficiency virus infection or in secondarily immunosuppressed recipients of organ transplants. Lymphoma is particularly common in patients who have undergone cyclosporine therapy. Typically, lymphoma in patients who are immunocompromised is of small, noncleaved cell or immunoblastic origin and has a B-cell phenotype. This condition often has an extranodal origin, and the most common sites include the central nervous system, bone marrow, gastrointestinal tract, lungs, heart, and liver. Renal involvement also occurs in these patients, but it is uncommon.

Degree of Confidence

In a patient with known lymphoma, low-attenuating perirenal masses or nodules almost always represent renal lymphoma. On contrast-enhanced CT scans, these lesions have attenuation values higher than those of simple fluid. Contrary to typical primary renal cell carcinoma, lymphomatous masses are often homogeneous and do not display significant enhancement. If the renal mass is exophytic, it causes vascular displacement and not encasement; the latter feature is common in renal cell carcinoma. Such findings may be associated with retroperitoneal adenopathy; however, when a single mass is found, their differentiation from renal cell carcinoma may become difficult, and occasionally, biopsy may become necessary (see Images 5-6). In perirenal lymphoma (halo sign on sonograms), the degree of confidence is higher.

MRI

Section 6 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

MRI findings in lymphoma are similar to those seen on CT scans, and they are diagnostic to the same degree (see Image 6). Usually, lymphoma displays low signal intensity on T1-weighted MRIs, and it is either isointense or moderately hyperintense on T2-weighted images. Lymphomatous tissue may be minimally enhancing, but it does not enhance as much as normal renal parenchyma; therefore, the lymphomatous tissue remains hypointense relative to the kidney on contrast-enhanced T1-weighted MRIs (see Images 21-23).

Degree of Confidence

The degree of confidence of MRI for renal lymphoma depends on the technique that is used for scanning. On breath-hold high-resolution MRIs that are obtained with nonenhanced and contrast-enhanced sequences, MRI is probably equivalent to CT scanning.

False Positives/Negatives

When renal involvement is unilateral, it can mimic renal cell carcinoma (see Image 6). When diffuse renal infiltration is noted without a discrete lesion, the possibility of a false-negative finding increases.

ULTRASOUND

Section 7 of 12  

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• Ultrasound
• Nuclear Medicine
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• Intervention
• Multimedia
• References

Findings

Ultrasonography often demonstrates single or multiple renal masses that have low-level echoes (see Image 24). Occasionally, the ultrasonographic findings may appear normal because of the small size of the renal nodules (see Image 4). In addition, varying degrees of hydronephrosis may be seen because of compression of the renal hilum that is caused by lymph nodes or obstruction of the ureters.

On sonograms, a perirenal hypoechoic halo is characteristic of perirenal lymphoma (see Image 14).

Degree of Confidence

The degree of confidence with the ultrasonographic assessment of renal involvement is lower than that of CT scanning or MRI; however, in patients with perirenal involvement, the pattern of a halo sign is a characteristic finding (see Image 14).

As a result of the homogeneous nature of large lesions, these lesions appear hypoechoic on ultrasonography, but without enhanced through-transmission. Occasionally, differentiating large lesions from a simple or a complicated cyst is difficult. If the lesions are small or if the nature of involvement is diffuse, the ultrasonographic findings can be normal (see Image 4).

NUCLEAR MEDICINE

Section 8 of 12  

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• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Gallium-67 citrate has been used for diagnosing and staging lymphoma. This radioisotope concentrates in lymphoma; gallium is taken up by lymphomatous tissue in the kidneys, and it is also concentrated in inflammatory masses of the kidney. Therefore, obtaining the clinical history of patients is important.

18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scanning has very high but not absolute specificity for malignant lymphoma. It has been reported that increased FDG uptake may also be observed in patients without active disease; in most cases, however, nonpathologic FDG accumulation is properly identified. Less frequently, inconclusive scans are encountered; these cases are usually caused by inflammation, which subsequently resolves.

The use of another agent, technetium-99m (⁹⁹Tc)-labeled antibody (LL2), has been advocated in imaging and staging lymphomas.

Degree of Confidence

Testing with gallium-67 citrate has an overall sensitivity of approximately 80% (see Image 25). However, in patients with high-grade lymphoma, gallium scanning has a higher degree of sensitivity. LL2 scanning also has a sensitivity of 80%; however, in patients with low-grade lymphoma, LL2 imaging usually has a higher degree of sensitivity.

False Positives/Negatives

Inconclusive scans are encountered with both gallium-67 citrate and FDG-PET. These cases are usually caused by inflammation, which subsequently resolves.

ANGIOGRAPHY

Section 9 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Usually, lymphoma is a hypovascular neoplasm; therefore, angiography cannot help in the diagnosis or staging of lymphomatous tumors. Thus, with contrast-enhanced CT scanning, the lesions remain hypovascular compared with the renal parenchyma when the contrast material is delivered to the kidney, via either intravenous injection for CT scanning or direct arterial injection for angiography. Therefore, the degree of confidence with angiography is low, and the degree of false-negative findings is high.

Degree of Confidence

The degree of confidence is low in the diagnosis of renal lymphoma with angiography.

False Positives/Negatives

False-negative diagnoses occur at a high rate.

INTERVENTION

Section 10 of 12  

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• Ultrasound
• Nuclear Medicine
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• Intervention
• Multimedia
• References

When a single mass with atypical imaging features is noted in a kidney, biopsy may occasionally be attempted to differentiate renal lymphoma from a primary renal cell carcinoma (see Images 5-6). Primarily, biopsy is performed because the treatments for the 2 neoplasms differ completely. In addition, in patients with another known primary malignancy, biopsy is often needed to differentiate metastasis to the kidney from renal infiltration by lymphoma.

Fine-needle aspiration with adjuvant flow cytometry is a useful technique for diagnosing and subtyping lymphomas.  However, the diagnosis and subclassification are often insufficient. Core biopsy material has a higher diagnostic yield and provides an opportunity for obtaining additional diagnostic and prognostic information that may not be easily derived from the fine-needle aspiration.

Patients with renal lymphoma are treated with chemotherapy, and surgical intervention is not indicated. The lesions are treated with systemic chemotherapy, and the response is usually favorable. The tumors often completely respond to such treatment without residual disease in the kidneys (see Images 1-2 and 12-13).

Medical/Legal Pitfalls

• The failure to correctly diagnose lymphoma may result in inappropriate treatment (eg, surgery), which creates a malpractice risk.
• Missing the diagnosis can create serious risks for the patient, especially if the lymphoma is confined to the kidneys. Occasionally, patients may not benefit from appropriate chemotherapy; as a result, the disease may advance further.

MULTIMEDIA

Section 11 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Media file 1:  Contrast-enhanced computed tomography (CT) scan obtained during the pyelographic phase for staging in a 17-year-old male adolescent with known lymphoma. This image reveals a hypoattenuating nodular pattern of different-sized lesions in both kidneys that represent bilateral renal lymphoma. Hypoattenuating nodes are also shown in the retroperitoneum.
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Media type:  CT

Media file 2:  Computed tomography scan in a 17-year-old male adolescent with known lymphoma (same patient as in Image 1). This image was obtained 7 months after the initiation of chemotherapy in the patient and reveals complete resolution of the bilateral hypoattenuating lesions. The appearance and function of the kidneys are normal. Note the complete resolution of the retroperitoneal nodes.
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Media type:  CT

Media file 3:  Contrast-enhanced computed tomography scan in a 15-year-old male adolescent with non-Hodgkin lymphoma. This image shows a bilateral pattern of multiple small nodules that are almost of equal size and involve both kidneys.
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Media type:  CT

Media file 4:  Sagittal baseline sonogram in a 15-year-old male adolescent with non-Hodgkin lymphoma (same patient as in Image 3). This image shows near-normal architecture of the left kidney. Both kidneys were reported as normal (left kidney size, 11.4 X 5.7 cm), and no indication of hydronephrosis was noted.
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Media type:  Ultrasound

Media file 5:  Contrast-enhanced computed tomography scan obtained during the nephrographic phase in a 93-year-old woman with non-Hodgkin lymphoma, in whom renal lymphoma mimicked renal cell carcinoma. This image reveals a single mass with heterogeneous attenuation that involves the right kidney, as well as an associated lymphadenopathy in the right side of the retroperitoneum. The findings suggest renal cell carcinoma with ipsilateral adenopathy. A normal variant of an extrarenal pelvis is noted in the left side.
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Media type:  CT

Media file 6:  Contrast-enhanced, breath-hold, T1-weighted magnetic resonance image (MRI) (repetition time, 190 ms; echo time, 4 ms) in a 93-year-old woman with non-Hodgkin lymphoma (same patient as in Image 5). This image shows a mass with heterogeneous signal intensity in the right kidney; areas of low signal intensity reveal necrosis in the mass. MRI was performed to assess the renal vascular pedicle and inferior vena cava, both of which were free of tumor. Because of the patient's history of non-Hodgkin lymphoma (for which she received treatment), biopsy was performed to exclude renal cell carcinoma. The diagnosis of renal lymphoma was proven, and the patient received appropriate treatment.
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Media type:  MRI

Media file 7:  Intravenous urogram obtained during the excretory phase in a 52-year-old woman with non-Hodgkin lymphoma who presented with flank pain (same patient as in Images 8 and 9). This image reveals a near-normal renal collecting system, with slightly enlarged kidneys and minimal narrowing of the proximal ureter that are suggestive of an external mass effect.
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Media type:  X-RAY

Media file 8:  Computed tomography (CT) scan in a 52-year-old woman with non-Hodgkin lymphoma (same patient as in Images 7 and 9). This image reveals diffuse renal lymphoma, in which diffuse, small nodules are scattered throughout both kidneys. The finding was not appreciated on the intravenous urogram and was only seen on contrast-enhanced CT scans. In fact, nonenhanced CT findings (not shown) were almost normal. The slight, narrowed ureter at the proximal portion, as seen on the urogram, was attributed to nephromegaly and compression of the ureter by the medial aspect of the kidney.
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Media type:  CT

Media file 9:  Autopsy specimen from a 52-year-old woman with non-Hodgkin lymphoma (same patient as in Images 7 and 8). Numerous lymphomatous nodules are visible throughout the kidneys.
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Media type:  Photo

Media file 10:  Computed tomography scan in a 36-year-old woman. This image reveals multiple lymphomatous masses that involve the right kidney, in which the largest mass shows areas of necrosis. A few lymph nodes are evident in the right-sided renal pedicle. Note that the patient has splenomegaly, with probable involvement of the liver and associated ascites and a vertebral bony lesion.
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Media type:  CT

Media file 11:  Computed tomography scan in a 53-year-old woman with lymphoma. A large relatively homogeneous mass involving the left kidney is associated with ipsilateral adenopathy. Note the beginning of minimal necrotic changes in the renal mass and the para-aortic nodes (cursors). A lymphomatous mass is seen in the liver. The pattern can be easily mistaken for renal cell carcinoma and associated with retroperitoneal adenopathy and hepatic metastasis. Note the thick-walled loop of small bowel from lymphoma anterior to the nodal mass.
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Media type:  CT

Media file 12:  Contrast-enhanced computed tomography (CT) scan in a 28-year-old woman with non-Hodgkin lymphoma, who presented with left flank pain. A renal sonogram (not shown) depicted left hydronephrosis and renal mass. This CT scan shows retroperitoneal extension of lymphoma to the left kidney, in which a large mass in the left side of the retroperitoneum extends into the left kidney. Adenopathy in the left hilar region appears to displace the renal vein and surround the renal artery without obstructing the blood flow. The posterior collecting system is dilated as a result of obstruction of the ureter by adenopathy that is present more caudally in the retroperitoneum (not shown).
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Media type:  CT

Media file 13:  Contrast-enhanced computed tomography scan in a 28-year-old woman with non-Hodgkin lymphoma (same patient as in Image 12) that was obtained to evaluate response to chemotherapy approximately 5 months after the patient underwent treatment. This image shows a mild degree of atrophy in the left kidney but complete resolution of the adenopathy and mass. The atrophy may also have been the result of long-standing hydronephrosis.
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Media type:  CT

Media file 14:  Sonogram in a 62-year-old man who presented with palpable flank masses (same patient as in Images 15-17). This image demonstrates perirenal lymphoma without retroperitoneal adenopathy. Although the left kidney appears to show no indication of a mass or hydronephrosis, a hypoechoic but solid-appearing area surrounds the kidney. The ultrasonographic findings may simply represent a perirenal complicated fluid collection or edema; however, perirenal lymphoma should be considered. Because of the underlying renal disease, the echotexture is increased throughout the kidney. This study was followed by computed tomography scanning and magnetic resonance imaging (see Images 15-17).
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Media type:  Ultrasound

Media file 15:  Nonenhanced computed tomography scan obtained in a 62-year-old man with a palpable flank mass and elevated levels of serum blood urea nitrogen and creatinine (same patient as in Images 14 and 16-17). This image shows large bilateral masses that cannot be distinguished from the renal parenchyma. A few calcifications are seen on the left side. No retroperitoneal adenopathy is noted.
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Media type:  CT

Media file 16:  T2-weighted magnetic resonance image (repetition time, 2000 ms; echo time, 80 ms) in a 62-year-old man with a palpable flank mass (same patient as Images 14-15 and 17). This image reveals homogeneous high signal intensity masses that surround the kidneys. The left kidney can be distinguished because of the collecting system and the vascular pedicle. Note the patency of the renal vascular pedicle in the left side.
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Media type:  MRI

Media file 17:  T2-weighted magnetic resonance image (repetition time, 2000 ms; echo time, 80 ms) in a 62-year-old man with a palpable flank mass (same patient as Images 14-16). This image shows patency of the renal vascular pedicle on the right side. The normal renal parenchyma has a signal intensity that is slightly different from that of the surrounding perirenal mass. A diagnosis of perirenal lymphoma was proven by percutaneous biopsy.
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Media type:  MRI

Media file 18:  Computed tomography scan in a 72-year-old woman with a known diagnosis of non-Hodgkin lymphoma. This image shows perirenal lymphoma with retroperitoneal adenopathy. Massive retroperitoneal adenopathy, splenomegaly, and a bilateral rim of low-attenuating tissue that surrounds the kidneys are noted. These findings are typical of perirenal lymphoma. The spleen has a large area of low attenuation as a result of tumor infiltration. Adenopathy, splenomegaly, and the perirenal process completely resolved after chemotherapy.
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Media type:  CT

Media file 19:  Nonenhanced computed tomography scan in a 22-year-old woman with non-Hodgkin lymphoma and elevated levels of blood urea nitrogen and creatinine. An infiltrative pattern of renal lymphoma is seen as lymphomatous infiltration within the interstitium of the kidneys, which causes bilateral nephromegaly. Note the areas of slightly lower attenuation and the preservation of the renal contour.
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Media type:  CT

Media file 20:  Contrast-enhanced computed tomography scan in a 36-year-old woman (same patient as in Images 21-23). This image shows bilateral small masses of different sizes due to lymphoma with involvement of the kidneys. The right kidney is more involved than the left. Associated adenopathy is noted in the retroperitoneum.
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Media type:  CT

Media file 21:  T1-weighted magnetic resonance image (repetition time, 650 ms; echo time, 25 ms) in a 36-year-old woman with bilateral renal lymphoma (same patient as in Images 20 and 22-23). This image reveals right-sided nephromegaly. In contrast to the computed tomography scan in Image 19, no discrete nodule can be seen in the kidneys.
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Media type:  MRI

Media file 22:  T2-weighted magnetic resonance image (repetition time, 2200 ms; echo time, 90 ms) in a 36-year-old woman with bilateral renal lymphoma (same patient as in Images 20-21 and 23). This image reveals heterogeneous intensity of the kidneys. Detection of discrete nodules is difficult.
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Media type:  MRI

Media file 23:  Contrast-enhanced T1-weighted magnetic resonance image (repetition time, 650 ms; echo time, 25 ms) in a 36-year-old woman with bilateral renal lymphoma (same patient as in Images 20-22). This image reveals enlargement of the right kidney with diffuse low signal intensity. The discrete low-intensity lesion in the left kidney is better depicted on the contrast-enhanced image. Note the splenomegaly with splenic involvement and ascites.
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Media type:  MRI

Media file 24:  Axial sonogram in a 22-year-old woman with known lymphoma. A baseline sonogram was performed, which demonstrated renal lymphoma. This image depicts a large kidney with heterogeneous echotexture and poorly defined areas of hypoechogenicity. A mild degree of hydronephrosis is noted. After chemotherapy, follow-up ultrasonographic images showed complete resolution of the renal lymphoma.
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Media type:  Ultrasound

Media file 25:  Gallium scan in a 55-year-old woman with known diffuse, poorly differentiated lymphoma who was admitted to the hospital because of renal failure. The patient had a creatinine level of 3. A sonogram (not shown) was performed and revealed no hydronephrosis. However, the echotexture of the kidneys was abnormal on the sonogram, and the possibility of renal lymphoma was suggested. This posterior view of the kidneys (Post) obtained at 72 hours after the injection of gallium-67 citrate shows multiple abnormal areas of increased uptake (arrows), particularly on the right side (R). This finding is consistent with renal involvement by lymphoma. Urinalysis results were normal, excluding underlying infection. Some residual gallium was noted in the colon. Gallium scan findings were normal 4 months after appropriate chemotherapy.
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Media type:  Nuclear Image

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

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Article Last Updated: Aug 20, 2007