An unusual appearance of renal lymphoma

Clinical Radiology (1988) 39, 452-453

An Unusual Appearance of Renal Lymphoma P. J. C A D M A N , D. R. M. L I N D S E L L and S. J. G O L D I N G

Departments of Radiology, John Radcliffe Hospital and University of Oxford, Oxford, UK

The kidney is a relatively common site of extranodal involvement by lymphoma and various patterns have been documented (Richmond et al., 1962). We describe a patient in whom renal involvement by non-Hodgkin's lymphoma produced unusual appearances on ultrasound and computed tomography (CT). The possible causes and relevance of these findings are discussed.

CASE REPORT A 65-year-old female presented with 18 months of lethargy, malaise and weight loss. Clinical examination revealed cervical and inguinal lymphadenopathy and a central upper abdominal mass. The kidneys were not palpable. Haemoglobin was 10.6 g/dl, white blood count 13.9x109/litre and erythrocyte sedimentation rate 41 mm/h. The platelet count was normal. Serum urea was elevated at 10.6 mm/litre but serum creatinine was normal. Cervical lymph node biopsy revealed non-Hodgkin's lymphoma of centroblastic/centrocytic follicular type. Abdominal ultrasound examination demonstrated a retroperitoneal lymph node mass. In addition both kidneys were enlarged and surrounded by a totally anechoic zone approximately 1 cm in diameter (Fig. 1). The parenchyma of the right kidney appeared normal but the left kidney contained ill-defined hypoechoic areas consistent with infiltration by lymphoma. On the right side in particular, a thin echogenic zone surrounding the abnormal area suggested that the latter lay within the renal capsule (Fig. la). Computed tomography of the chest and abdomen, performed for staging purposes, confirmed retroperitoneal lymphadenopathy with no supra-diaphragmatic disease. Both kidneys were enlarged and after enhancement had a symmetrica! halo of poorly enhancing material (Fig. 2). Attenuation values from this area rose from 38.8 HU (SD 6.3) before enhancement to 63.8 HU (SD 6.4) after enhancement, indicating that the abnormal area consisted of perfused tissue. There was some disruption of the parenchymal pattern bilaterally, consistent with infiltration. She was treated with cyclical combination chemotherapy (vincristine, adriamycin, cyclophosphamide and prednisolone) and responded well to treatment. Serial ultrasound examinations showed gradual resolution of the renal abnormalities and 6 months after starting treatment the kidneys appeared normal on both ultrasound and CT.

lesions a l t h o u g h this has b e e n described ( K a u d e and Lacey, 1978). R a r e l y the masses are of increased echogenicity. O t h e r patterns of renal i n v o l v e m e n t are also seen. I n a p p r o x i m a t e l y 50% of patients t h e r e is peri-renal l y m p h a d e n o p a t h y which usually displaces the k i d n e y but in 25% of patients the k i d n e y is infiltrated directly ( H e i k e n et al., 1986). Diffuse renal i n v o l v e m e n t and solitary masses are also occasionally seen. R e n a l e n c a s e m e n t by l y m p h o m a has b e e n described previously and has b e e n t h o u g h t to be due to extracapsular spread f r o m r e t r o p e r i t o n e a l l y m p h n o d e disease (Carol and Ta, 1980; H e i k e n et al., 1986). I n o u r p a t i e n t the findings were surprising in that the renal disease was quite separate f r o m the l y m p h a d e n o p a t h y and was bilateral and symmetrical. B o t h o u r techniques demonstrated involvement of the underlying p a r e n c h y m a and our u l t r a s o u n d findings suggested that

(a)

DICUSSION R e n a l i n v o l v e m e n t by l y m p h o m a has b e e n studied by R i c h m o n d et al. (1962) w h o s h o w e d an incidence of 33.5% at p o s t - m o r t e m e x a m i n a t i o n in the days prior to effective therapy. M o r e recently the incidence on presentation has b e e n s h o w n to lie b e t w e e n 2.7 and 6% (Ellert and Kreel, 1980; B u r g e n e r and H a m l i n , 1981). N o n - H o d g k i n ' s l y m p h o m a m o r e c o m m o n l y involves the kidney than H o d g k i n ' s l y m p h o m a . A b o u t 75% of cases with renal i n v o l v e m e n t have multiple n o d u l e s of varying size and in half of these involvement is bilateral. This p a t t e r n is well d e m o n strated on b o t h u l t r a s o u n d and C T (Carol and Ta, 1980; H e i k e n et al., 1983). O n u l t r a s o u n d the n o d u l e s are characteristically h y p o e c h o i c or anechoic. T h e r e is usually no posterior echo e n h a n c e m e n t distal to the

(b) Fig. 1 - Longitudinal (a) and transverse (b) ultrasound images of the right kidney showing a totally anechoic rim of tissue which appears to lie beneath the capsule of the kidney (arrow).

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possibility was excluded by the CT findings, which indicated conclusively that the abnormal area consisted of perfused tissue. We therefore believe that the findings represent an unusual and hitherto undescribed manifestation of renal lymphoma in which the renal parenchyma is surrounded by a symmetrical halo of neoplasm, possibly beneath the renal capsule. In our patients these changes resolved in parallel with other areas of disease during treatment. REFERENCES

Fig. 2 - A C T image of the abdomen showing a poorly enhancing zone of abnormal tissue symmetrically surrounding the kidney on each side. The renal cortex shows inhomogeneous enhancement in keeping with intrarenal lymphoma. There is extensive retroperitoneal lymphadenopathy (arrows) which is separate from the renal disease.

the abnormal halo was intracapsular rather than perirenal. The ultrasound appearances could have been due to a peri-renal fluid collection of lymph, urine or blood. This

Burgener, FA & Hamlin, DJ (1981). Histiocytic lymphoma of the abdomen: radiographic spectrum. American Journal of Roentgenology, 137, 337-342. Carol, BA & Ta, HN (1980). The ultrasound appearances of extranodal abdominal lymphoma. Radiology, 136, 419-425. Ellert, J & Kreel, L (1980). The Role of CT in the initial staging and subsequent management of the lymphomas. Journal of Computed Assisted Tomography, 4, 368-391. Heiken, JP, Gold, RP, Schnur, MJ, King, DL, Bashist, B & Glazer, HS (1983). Computed tomography of renal lymphoma with ultrasound correlation. Journal of Computer Assisted Tomography, 7, 245-250. Heiken, JP, McLennan, BL & Gold, RP (1986). Renal lymphoma. Seminars in Ultrasound, CT and MR, 7, 58-66. Kaude, JV & Lacey, GD (1978). Ultrasonography in renal lymphoma. Journal of Clinical Ultrasound, 6, 321-323. Richmond J, Sherman, RS, Diamond, HD & Craver, L (1962). Renal lesions associated with malignant lymphoma. American Journal of Medicine, 32, 184-207.

Book Reviews Case Studies in Diagnostic Imaging. By P. Nisbet, W. Gedroyc and S. Rankin. Springer-Verlag, Berlin, 1987, 180 pp., 80 figs. This small book consists of 80 cases presented as radiographs and brief clinical information with the diagnosis over the page. The answers include a brief description of the radiological findings and differential diagnosis with, in some cases, additional comments. The intent is to simulate the film viewing session in the final Fellowship examination of the Royal College of Radiologists. In accordance with the format of this examination, the cases are in groups of eight and each example includes a maximum of three films. Two of the authors are currently senior registrars and presumably have recent experience of the Fellowship. Although it is stated in the preface that the book is also intended as preparation for the MRCP examination, the format and the level of difficulty of the cases makes this inappropriate. In far too many of the cases, the poor quality of the reproduced radiographs prevented identification of radiographic signs even in hindsight. These examples, where perception could not be reasonably tested, were often of an esoteric nature. It would have been more useful and would have simulated the film viewing session more closely if these examples had been replaced by more prosaic cases with clearer radiographs. The reader's deductive ability is tested to some extent but in many cases the discussion does not include the role of further investigations. In a few instances, the examination used to illustrate cases is inappropriate yet does not engender critical appraisal. In summary, the shortcomings of this book are likely to limit its usefulness for the final Fellowship candidate. G. H. Whitehouse

Multiple Choice Questions in Radiodiagnosis. By Ann Crosier, David Finlay and Paula Paciorek. Churchill Livingstone, Edinburgh, 1986, 122 pp. This pocket sized book of multiple choice questions is intended for candidates preparing for the final examination in diagnostic radiology and has come out at a time when several other books of multiple choice questions are being published. It is an extraordinarily difficult task to prepare satisfactory multiple choice questions and those who do so are to be congratulated on the work and effort put into such a publication. The book covers a wide range of radiological and clinical topics suitable for the final Fellowship examination, and is divided into ten papers of 30 questions each. There are no specific references given to the questions and answers, although at the end there is a bibliography listing the text from which the majority of the questions are verified. Having myself prepared multiple choice questions over many years, the difficulty in obtaining an unambiguous stem and answers is very evident, and if I have any criticism at all it is only the use of words such as, 'commonly', 'can sometimes be', 'usually', and 'there are often'. Perhaps one or two of the questions are a little dated; an example being the appearances of fetal death, which are more likely to be included in a question on ultrasound rather than on plain radiography. However, these are minor criticisms of what is a valuable book for preFellowship revision. I. M. Prosser