| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Original Report |
1 Section of Pediatric Radiology, C.S. Mott Children's Hospital, University of
Michigan Medical Center, 1500 E. Medical Center Dr., Ann Arbor, MI
48109-0252.
2 Present address: Radiology Department, Wake Forest University School of
Medicine, Medical Center Blvd., Winston-Salem, NC 27157.
3 Section of Pediatric Hematology/Oncology, Department of Pediatrics and
Communicable Diseases, Bone Marrow Transplant, B1-207 CGC, Ann Arbor, MI
48109-0914.
Received April 15, 2002;
accepted after revision July 23, 2002.
Address correspondence to P. J. Strouse.
Abstract
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CONCLUSION. Renal lymphoma was seen in 11 children, most commonly due to non-Hodgkin's lymphoma (n = 10, 91%) and Burkitt's subtype (n = 5, 45%). Multiple bilateral masses were the most common CT appearance. Less common presentations included focal solitary masses or an engulfing mass. Retroperitoneal lymph node enlargement and other organ involvements were common associated findings. Five of six patients with renal involvement at initial diagnosis have had cures or remissions. Therefore, renal involvement at the time of initial diagnosis with lymphoma does not portend a poor prognosis.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CT studies at our institution were performed on a 9800 CT scanner (General Electric Medical Systems, Milwaukee, WI) before 1995 and on a Hi-Speed Advantage helical CT scanner (General Electric Medical Systems) since 1995. CT scans were routinely obtained with an oral contrast preparation and bolus injection of IV contrast material. Unenhanced scans were not routinely obtained. Field of view and scan thickness were tailored to patient size. In most patients, axial 7-mm-thick images were obtained in the chest and upper abdomen to the iliac crests, with serial 10-mm-thick images extending from the iliac crests to below the pubic symphysis. Smaller slice thicknesses were used in younger children. Because we are a tertiary referral center, some patients had their initial diagnostic scans obtained elsewhere, with techniques slightly varying from ours.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Three patterns of renal lymphoma were identified. Seven patients had multiple bilateral masses enhancing less than normal renal parenchyma (Figs. 1 and 2). The number and size of individual lesions varied from patient to patient. Focal renal masses were identified in three patients: one with bilateral solitary masses and two with unilateral solitary masses (Fig. 3A,3B). One patient had a large retroperitoneal mass engulfing the left kidney (Fig. 4). Retroperitoneal lymph node enlargement was identified in eight patients (73%). In addition, all 11 patients had other sites of active disease concomitant to the renal involvement, including the chest (n = 6), liver (n = 3), pancreas (n = 3), bone-bone marrow (n = 2), head and neck (n = 2), ovary (n = 1), stomach (n = 1), and spleen (n = 1).
|
|
|
|
|
Unenhanced images were available for only one patient. In this patient, bilateral solitary renal masses were of high attenuation compared with normal renal parenchyma before contrast administration and low attenuation compared with normal renal parenchyma after contrast administration (Fig. 3A,3B). In all 11 patients, the lymphomatous lesions were lower in attenuation than normal renal parenchyma on contrast-enhanced images. In general, the renal lesions were homogeneous, although some larger lesions did show slight heterogeneity. In patients with multiple masses, the largest individual lesion ranged from 1-4 cm (mean, 2.5 cm), whereas the solitary masses (two unilateral and one bilateral) were 3.5-7 cm (mean, 5 cm). Larger and more peripheral lesions caused at least mild contour deformity in eight of 10 patients. In the other patient, the engulfing lymphomatous mass slightly splayed the renal hilum. Calcifications were not seen in any renal lesion.
During our review, we also identified three patients with unilateral ureteral obstruction due to retroperitoneal or pelvic lymphoma. None of these patients had direct renal involvement with lymphoma.
Of the 11 patients identified with direct renal involvement with lymphoma, 10 patients (91%) had non-Hodgkin's lymphoma and one (9%) had Hodgkin's lymphoma. The overall prevalence of non-Hodgkin's lymphoma in our study group was 45% (62/139 patients). Of the 10 patients with non-Hodgkin's lymphoma, subtypes were Burkitt's (n = 5), large cell (n = 3), lymphoblastic (n = 1), and T-cell lymphoblastic lymphoma (n = 1).
At follow-up, only one patient of the six with renal involvement at the time of diagnosis was deceased, whereas two of the five with renal involvement at the time of recurrence were deceased, and a third patient with renal involvement was considered untreatable and transferred elsewhere for palliative care. Follow-up time of surviving patients ranged from 3 to 7 years.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Five (45%) of our 11 patients identified with lymphomatous involvement of the kidneys had a pathologic diagnosis of Burkitt's lymphoma. These findings contrast with those seen in adult patients in whom renal involvement by Burkitt's lymphoma is uncommonly reported. Only one of 11 patients in our study had a pathologic diagnosis of Hodgkin's lymphoma [1, 3]. Renal involvement with Hodgkin's lymphoma is also reported to be uncommon in adults [1, 2].
The pattern of appearances in children showed similar characteristics to that described in adults; however, the appearance of multiple, bilateral renal masses was heavily prevalent in children [1,2,3]. Less common appearances are solitary masses (unilateral or bilateral) and an engulfing retroperitoneal mass. We did not identify a case of diffuse renal enlargement due to lymphoma in our series. Our findings are similar to the renal abnormalities seen by Ng et al. [6] in a review of 80 pediatric patients with non-Hodgkin's lymphoma. In their series, nine patients had renal involvement: six with multiple bilateral masses, two with solitary masses, and one with diffuse renal enlargement. Retroperitoneal lymph node enlargement was present in 73% of our patients, similar to the prevalence given in the literature concerning adults [2, 3].
The CT findings of renal lymphoma are not specific for lymphoma. Multiple, small bilateral masses can be seen in patients with leukemia, particularly acute myelogenous leukemia, multiple angiomyolipomas, fungal infection, cystic renal disease, and metastatic disease. Distinction from cystic renal disease is made by examining the attenuation of the lesions. Cysts are usually of fluid attenuation, whereas lymphoma is of soft-tissue attenuation. Angiomyolipomas can usually be identified by their fat content. Focal fungal lesions in the kidneys are usually small and occur in immunocompromised patients in association with hepatic and splenic fungal lesions. Multiple renal lesions due to metastases are extremely rare in childhood. The differential diagnosis for a solitary renal mass includes Wilms' tumor in young children, renal cell carcinoma in older children, metanephric adenoma, solitary angiomyolipoma, and focal infection. The finding of an engulfing retroperitoneal mass can be confused with that of a retroperitoneal tumor such as a neuroblastoma. Aggressive renal neoplasms, such as rhabdoid tumors, can arise centrally and engulf the kidney and appear similar to lymphoma. On imaging, diffuse infiltration of the kidney with renal enlargement is difficult to distinguish from a myriad of other causes of diffuse renal enlargement. Diffuse renal enlargement is much more often a manifestation of tumor lysis, a response to chemotherapeutic agents, or an infection rather than a direct manifestation of neoplasm in the kidney. Although the CT appearances of renal disease due to lymphoma are nonspecific, the association with retroperitoneal lymph node enlargement and involvement of other sites often suggests the proper diagnosis. Particularly in the second decade of life, when renal masses are uncommon, lymphoma should be a consideration in any renal mass.
Patients with lymphoma may also show abnormalities of the kidneys that are not related to direct cellular infiltration. Retroperitoneal or pelvic tumor masses can cause obstructive uropathy with resultant hydronephrosis, altered renal perfusion, and increased kidney size. Renal enlargement may also be caused by tumor lysis syndrome. In this syndrome, lysis of tumor cells causes metabolic disturbances and urate deposits in the kidneys with resultant acute renal insufficiency [8]. Renal infection can produce renal enlargement, focal masses, and innumerable small masses. These complications must be considered when a renal abnormality is seen in a patient with lymphoma.
Renal failure in non-Hodgkin's lymphoma is a frequent complication of which the clinician must be aware [9,10,11]. In most cases, renal failure is not due to primary or secondary renal lymphoma but to ureteral obstruction from lymphomatous ureteral invasion or secondary compression from involved retroperitoneal lymph nodes [9, 10]. Occasionally, renal failure results from vascular obstruction related to regional nodal disease [9]. Numerous other potential causes for acute renal failure in patients with lymphoma have been identified [9, 10]. Primary non-Hodgkin's lymphoma of the kidneys with resultant acute renal failure is rare [11]. In most cases, renal dysfunction resolves quickly with induction chemotherapy. Dialysis is only required in cases in which oliguria or severe electrolyte abnormalities are a presenting feature. Whether the presence of renal involvement at diagnosis increases the risk for tumor lysis syndrome during induction therapy is unclear. In general, patients who present with elevated serum creatinine levels are at increased risk for metabolic complications during induction therapy for non-Hodgkin's lymphoma [12]. Although an association of renal lymphoma with severe tumor lysis syndrome has yet to be reported, caution is usually warranted in such patients because of its potential occurrence.
In summary, we have presented a retrospective review of the CT appearance of renal lymphoma in pediatric patients. Multiple bilateral masses are the most common appearance with less common presentations of a solitary or an engulfing mass. Associated retroperitoneal lymph node enlargement and extrarenal disease are common. Renal disease may be present at the time of diagnosis and does not necessarily portend a poor prognosis. Renal disease at the time of recurrence, however, is associated with heightened mortality.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Sheth, S. Ali, and E. Fishman Imaging of renal lymphoma: patterns of disease with pathologic correlation. RadioGraphics, July 1, 2006; 26(4): 1151 - 1168. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Manzitti, P. Toma, A. Rizzo, C. Gambini, and A. Garaventa Problems in Colon Cancer and a Child With Renal Lymphoma: CASE 3. Mature B-Cell Renal Lymphoma Presenting As a Single Osseous Mass in a Child J. Clin. Oncol., August 1, 2005; 23(22): 5257 - 5259. [Full Text] [PDF]
|
|
|
|
 |
|
 N. M. Blitman, R. G. Berkenblit, A. M. Rozenblit, and T. L. Levin Renal Medullary Carcinoma: CT and MRI Features Am. J. Roentgenol., July 1, 2005; 185(1): 268 - 272. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
