European Journal of Radiology, 15 (1992) 146-148
146
0 1992 Elsevier Science Publishers B.V. All rights reserved. 0720-048X/92/$05.00
EURRAD 00305
An unusual case of renal involvement Daniela Castagnone a, Clara Mandellib,
in non-Hodgkin
lymphoma
Roberto Rivolta”, Nicola Bonelli a and Luca Baldini”
aServizio di Radiologia, b Istituto di Patologia Medica III and ’ Servizio Autonomo di Ematologia, IRCCS Ospedale Maggiore. Milan, Italy (Received 24 February 1992; accepted 3 April 1992)
Key words: Kidney, CT; Kidney, ultrasound study; Kidney, lymphoma; Computed tomography, kidney; Ultrasound,
kidney
Abstract Ultrasonography of a patient with non-Hodgkin lymphoma revealed a thick subcapsular layer of lymphomatous tissue surrounding the kidney, quite separate from retroperitoneaf nodes, that simulated a perirenal fluid collection or hematoma; the solid appearance on computed tomography scans and fine needle biopsy led to the diagnosis.
Introduction Renal involvement in lymphoma is detected in vivo in a small proportion (2.7-6%) of cases [ 1,2], compared with autoptic evidence of renal disease in 3352 % of the cases [ 31; these figures, however, refer to old series when diagnosis and therapy were less effective. The most common finding is a multinodular lesion or direct invasion by retroperitoneal disease that distorts or enlarges the kidney [4-61. Ultrasonography (US) and computed tomography (CT) results are aspecific in these cases, and renal lymphoma can simulate other primary or secondary neoplastic renal diseases [4,7,8]. This paper reports an uncommon presentation of non-Hodgkin lymphoma simulating a benign condition. Case report A diagnosis of intermediate grade non-Hodgkin lymphoma, stage IV A, with generalized lymphadenopathy, hepatic and bone marrow involvement was made in a 63-year-old man three years previous to this referral. Chemotherapy with aggressive multidrug regiments achieved only partial remission, and subsequent interCorrespondence to: Dr. Daniela Castagnone, Servizio di Radiologia Medica, Ospedale Polichnico, Pad. Sacco, Via F. Sforza 35, 20122 Milan, Italy.
mittent chemotherapy ensured good performance status until splenomegaly presented. At US examination the two known liver localizations and lymphadenopathy in the hepatic hilar, peripancreatic and left paraaortic regions were unchanged despite the initial remission. The spleen was compressed by an enlarged left liver lobe. A hypoechoic layer, about 2 cm thick, surrounded the lower half of the left kidney which, however, had a normal appearance (Fig. 1). No echogenic stripe due to the renal capsule was identified between these two structures. Unenhanced CT, because of a monoclonal component, demonstrated an enlarged left kidney surrounded by a solid mass with a slightly higher density than that of renal parenchyma. The posterior perirenal fascia was only slightly thickened (Fig. 2). Left paraaortic nodes were separate from the mass. A fine needle aspiration biopsy under US guidance yielded lymphatic tissue compatible with non-Hodgkin lymphoma, low grade malignancy, in agreement with the previous histologic diagnosis on a submandibular node. Discussion Primary renal lymphoma is very rare because of the lack of lymphoid tissue in the kidney. Lymphoma can involve the kidney both by hematogenous spread and
Fig. 1. (a) Ultrasound longitudinal scan of the left kidney shows a hypoechoic layer surrounding the lower portion of the parenchyma (cross). No echogenic stripe, supported by the renal capsule, is interposed between them, as in a subcapsular lesion. (b) An oblique scan demonstrates paraaortic nodes medially to the superior portion of the kidney (cursor), quite separate from the subcapsular lymphomatous infiltration.
by direct invasion of the perirenal space [4,8]. In the former case single or multiple nodular masses are found, and the multinodular pattern is described in several reports as the most frequent finding in renal lymphoma. On US these masses are hypoechoic or anechoic in relation to renal parenchyma and do not show posterior echo enhancement; they rarely have increased echogenicity. On CT they have almost the same density as renal parenchyma, and are therefore scarcely detectable in the precontrast scans, and after injection of
contrast medium their density is lower than that of renal parenchyma. Direct invasion by the spread of lymphomatous tissue in the perirenal space is less common [4,6,7]. Perirenal lesions were, however, observed by Charnsangavej [ 81 in 43 % of 30 patients. Such a lesion usually presents as strands of thickened fascia and nodularity in the perirenal space, or a mass with a CT density similar to or slightly higher than normal renal parenchyma, that invades the kidney locally or diffusely. Fur-
Fig. 2. (a) Unenhanced computed tomography of the left kidney reveals a solid slightly hyperdense layer surrounding the parenchyma, thicker in the inferior portion. (b) A more cranial scan shows paraaortic nodes with no continuity with the mass. There are strands of thickened fascia in the perirenal space.
148
thermore, there is evidence of contiguous lymphomatous involvement. These patterns are demonstrated at US as hypoechoic masses distorting and enlarging the kidney in continuity with retroperitoneal disease. A third US and CT pattern has occasionally been reported [ 9,10,11], namely, a layer of lymphomatous tissue encircling the kidney, quite separate from retroperitoneal nodes disease. The kidney is also enlarged in this condition, but can be differentiated at US and CT from perirenal involvement because, rather than being distorted and infiltrated, the kidney is surrounded by a hypoechoic halo that is hyper- or isodense on precontrast CT scans becoming hypodense after contrast injection. US is superior to CT in distinguishing between lymphomatous and renal parenchyma because the difference in echogenicity between these tissues is greater than the difference in density, especially if no contrast enhancement is employed [9]. It has been suggested that this infiltration is subcapsular rather than perirenal [lo] because at US it appeared beneath an echogenic stripe probably representing the renal capsule. Even in the case presented here, lymphomatous tissue was contiguous with renal parenchyma and there was no interposed echogenic structure due to the renal capsule. Subcapsular lesions, as reported here have rarely been described in the literature; Charnsangavej reported 2 of 13 cases [8], Jafri one out of 16 [7], and Lorigan and Cadman one case each [ 9, lo]. They are usually an expression of disseminated disease with concurrent [ 7,8], but not always contiguous [ lo] paraaortic nodes enlargement, as in our patient, but they have been reported even in the absence of adenopathies [9]. Unilateral involvement, as in our case, can be misleading on US examination because it mimics a perirenal fluid collection or hematoma, and only its solid appearance on CT scan enables a correct diagnosis to be made. In conclusion, the more common presentations of renal and perirenal lymphoma may simulate a primary renal neoplasm or secondary involvement by retroperitoneal mesenchymal tumor. Associated retroperitoneal
adenopathies and splenomegaly can suggest the diagnosis. On the contrary, subcapsular involvement, often asymptomatic, can be misleading, especially if unilateral and in absence of contiguous lymphadenopathy. In this case the US appearance can simulate a benign condition as hematoma or perirenal fluid collection. Diagnosis can be based on combined CT and US because of the higher density and lower echogenicity of lymphomatous tissue compared with renal parenchyma. US guided fine needle biopsy may be useful in excluding other diagnoses and in supporting that of lymphoma, especially if the cytologic specimen can be compared with the histologic finding at the time of the original diagnosis.
References 1 Ellert J, Kreel L. The role of CT in the initial staging and subsequent management of the lymphomas. J Comput Assist Tomogr 1980; 4: 368-391. 2 Burgener FA, Hamlin DJ. Histiocytic lymphoma of the abdomen: radiographic spectrum. AJR 1981; 137: 337-342. 3 Richmond J, Sherman RS, Diamond HD, Cravers L. Renal lesions associated with malignant lymphoma. Am J Med 1962; 32: 184-207. 4 Heiken JP, McClennan BL, Gold RP. Renal lymphoma. Seminars in Ultrasound, CT and MRI 1986; 7: 58-66. 5 Carroll BA, Ta HN. The ultrasonic appearance of extranodal abdominal lymphoma. Radiology 1980; 136: 419-425. 6 Heiken JP, Gold RP, Schnur MJ, King DL, Bashist B, Glazer HS. Computed tomography of renal lymphoma with ultrasound correlation. J Comput Assist Tomogr 1983; 7: 245-250. 7 Jafri SHZ, Bree RL, Amendola MA, Glazer GM, Schwab RE, Francis IR, Borlaza G. CT of renal and perirenal non-Hodgkin lymphoma. AJR 1982; 138: 1101-1105. 8 Charnsangavej C. Lymphoma of the genitourinary tract. Radio1 Clin North Am 1990; 4: 865-877. 9 Lorigan JG, David CL, Shirkhoda A, Eftekhari F, Alexanian R. Macroglobulinaemic lymphoma presenting with perirenal masses. Br J Radio1 1988; 61: 1077-1078. 10 Cadman PJ, Lindsell DRM, Golding SJ. An unusual appearance of renal lymphoma. Clin Radio1 1988; 39: 452-453. 11 Davies RA. Unusual appearance of renal lymphoma. Clin Radio1 1990; 41: 365-366.
146
0 1992 Elsevier Science Publishers B.V. All rights reserved. 0720-048X/92/$05.00
EURRAD 00305
An unusual case of renal involvement Daniela Castagnone a, Clara Mandellib,
in non-Hodgkin
lymphoma
Roberto Rivolta”, Nicola Bonelli a and Luca Baldini”
aServizio di Radiologia, b Istituto di Patologia Medica III and ’ Servizio Autonomo di Ematologia, IRCCS Ospedale Maggiore. Milan, Italy (Received 24 February 1992; accepted 3 April 1992)
Key words: Kidney, CT; Kidney, ultrasound study; Kidney, lymphoma; Computed tomography, kidney; Ultrasound,
kidney
Abstract Ultrasonography of a patient with non-Hodgkin lymphoma revealed a thick subcapsular layer of lymphomatous tissue surrounding the kidney, quite separate from retroperitoneaf nodes, that simulated a perirenal fluid collection or hematoma; the solid appearance on computed tomography scans and fine needle biopsy led to the diagnosis.
Introduction Renal involvement in lymphoma is detected in vivo in a small proportion (2.7-6%) of cases [ 1,2], compared with autoptic evidence of renal disease in 3352 % of the cases [ 31; these figures, however, refer to old series when diagnosis and therapy were less effective. The most common finding is a multinodular lesion or direct invasion by retroperitoneal disease that distorts or enlarges the kidney [4-61. Ultrasonography (US) and computed tomography (CT) results are aspecific in these cases, and renal lymphoma can simulate other primary or secondary neoplastic renal diseases [4,7,8]. This paper reports an uncommon presentation of non-Hodgkin lymphoma simulating a benign condition. Case report A diagnosis of intermediate grade non-Hodgkin lymphoma, stage IV A, with generalized lymphadenopathy, hepatic and bone marrow involvement was made in a 63-year-old man three years previous to this referral. Chemotherapy with aggressive multidrug regiments achieved only partial remission, and subsequent interCorrespondence to: Dr. Daniela Castagnone, Servizio di Radiologia Medica, Ospedale Polichnico, Pad. Sacco, Via F. Sforza 35, 20122 Milan, Italy.
mittent chemotherapy ensured good performance status until splenomegaly presented. At US examination the two known liver localizations and lymphadenopathy in the hepatic hilar, peripancreatic and left paraaortic regions were unchanged despite the initial remission. The spleen was compressed by an enlarged left liver lobe. A hypoechoic layer, about 2 cm thick, surrounded the lower half of the left kidney which, however, had a normal appearance (Fig. 1). No echogenic stripe due to the renal capsule was identified between these two structures. Unenhanced CT, because of a monoclonal component, demonstrated an enlarged left kidney surrounded by a solid mass with a slightly higher density than that of renal parenchyma. The posterior perirenal fascia was only slightly thickened (Fig. 2). Left paraaortic nodes were separate from the mass. A fine needle aspiration biopsy under US guidance yielded lymphatic tissue compatible with non-Hodgkin lymphoma, low grade malignancy, in agreement with the previous histologic diagnosis on a submandibular node. Discussion Primary renal lymphoma is very rare because of the lack of lymphoid tissue in the kidney. Lymphoma can involve the kidney both by hematogenous spread and
Fig. 1. (a) Ultrasound longitudinal scan of the left kidney shows a hypoechoic layer surrounding the lower portion of the parenchyma (cross). No echogenic stripe, supported by the renal capsule, is interposed between them, as in a subcapsular lesion. (b) An oblique scan demonstrates paraaortic nodes medially to the superior portion of the kidney (cursor), quite separate from the subcapsular lymphomatous infiltration.
by direct invasion of the perirenal space [4,8]. In the former case single or multiple nodular masses are found, and the multinodular pattern is described in several reports as the most frequent finding in renal lymphoma. On US these masses are hypoechoic or anechoic in relation to renal parenchyma and do not show posterior echo enhancement; they rarely have increased echogenicity. On CT they have almost the same density as renal parenchyma, and are therefore scarcely detectable in the precontrast scans, and after injection of
contrast medium their density is lower than that of renal parenchyma. Direct invasion by the spread of lymphomatous tissue in the perirenal space is less common [4,6,7]. Perirenal lesions were, however, observed by Charnsangavej [ 81 in 43 % of 30 patients. Such a lesion usually presents as strands of thickened fascia and nodularity in the perirenal space, or a mass with a CT density similar to or slightly higher than normal renal parenchyma, that invades the kidney locally or diffusely. Fur-
Fig. 2. (a) Unenhanced computed tomography of the left kidney reveals a solid slightly hyperdense layer surrounding the parenchyma, thicker in the inferior portion. (b) A more cranial scan shows paraaortic nodes with no continuity with the mass. There are strands of thickened fascia in the perirenal space.
148
thermore, there is evidence of contiguous lymphomatous involvement. These patterns are demonstrated at US as hypoechoic masses distorting and enlarging the kidney in continuity with retroperitoneal disease. A third US and CT pattern has occasionally been reported [ 9,10,11], namely, a layer of lymphomatous tissue encircling the kidney, quite separate from retroperitoneal nodes disease. The kidney is also enlarged in this condition, but can be differentiated at US and CT from perirenal involvement because, rather than being distorted and infiltrated, the kidney is surrounded by a hypoechoic halo that is hyper- or isodense on precontrast CT scans becoming hypodense after contrast injection. US is superior to CT in distinguishing between lymphomatous and renal parenchyma because the difference in echogenicity between these tissues is greater than the difference in density, especially if no contrast enhancement is employed [9]. It has been suggested that this infiltration is subcapsular rather than perirenal [lo] because at US it appeared beneath an echogenic stripe probably representing the renal capsule. Even in the case presented here, lymphomatous tissue was contiguous with renal parenchyma and there was no interposed echogenic structure due to the renal capsule. Subcapsular lesions, as reported here have rarely been described in the literature; Charnsangavej reported 2 of 13 cases [8], Jafri one out of 16 [7], and Lorigan and Cadman one case each [ 9, lo]. They are usually an expression of disseminated disease with concurrent [ 7,8], but not always contiguous [ lo] paraaortic nodes enlargement, as in our patient, but they have been reported even in the absence of adenopathies [9]. Unilateral involvement, as in our case, can be misleading on US examination because it mimics a perirenal fluid collection or hematoma, and only its solid appearance on CT scan enables a correct diagnosis to be made. In conclusion, the more common presentations of renal and perirenal lymphoma may simulate a primary renal neoplasm or secondary involvement by retroperitoneal mesenchymal tumor. Associated retroperitoneal
adenopathies and splenomegaly can suggest the diagnosis. On the contrary, subcapsular involvement, often asymptomatic, can be misleading, especially if unilateral and in absence of contiguous lymphadenopathy. In this case the US appearance can simulate a benign condition as hematoma or perirenal fluid collection. Diagnosis can be based on combined CT and US because of the higher density and lower echogenicity of lymphomatous tissue compared with renal parenchyma. US guided fine needle biopsy may be useful in excluding other diagnoses and in supporting that of lymphoma, especially if the cytologic specimen can be compared with the histologic finding at the time of the original diagnosis.
References 1 Ellert J, Kreel L. The role of CT in the initial staging and subsequent management of the lymphomas. J Comput Assist Tomogr 1980; 4: 368-391. 2 Burgener FA, Hamlin DJ. Histiocytic lymphoma of the abdomen: radiographic spectrum. AJR 1981; 137: 337-342. 3 Richmond J, Sherman RS, Diamond HD, Cravers L. Renal lesions associated with malignant lymphoma. Am J Med 1962; 32: 184-207. 4 Heiken JP, McClennan BL, Gold RP. Renal lymphoma. Seminars in Ultrasound, CT and MRI 1986; 7: 58-66. 5 Carroll BA, Ta HN. The ultrasonic appearance of extranodal abdominal lymphoma. Radiology 1980; 136: 419-425. 6 Heiken JP, Gold RP, Schnur MJ, King DL, Bashist B, Glazer HS. Computed tomography of renal lymphoma with ultrasound correlation. J Comput Assist Tomogr 1983; 7: 245-250. 7 Jafri SHZ, Bree RL, Amendola MA, Glazer GM, Schwab RE, Francis IR, Borlaza G. CT of renal and perirenal non-Hodgkin lymphoma. AJR 1982; 138: 1101-1105. 8 Charnsangavej C. Lymphoma of the genitourinary tract. Radio1 Clin North Am 1990; 4: 865-877. 9 Lorigan JG, David CL, Shirkhoda A, Eftekhari F, Alexanian R. Macroglobulinaemic lymphoma presenting with perirenal masses. Br J Radio1 1988; 61: 1077-1078. 10 Cadman PJ, Lindsell DRM, Golding SJ. An unusual appearance of renal lymphoma. Clin Radio1 1988; 39: 452-453. 11 Davies RA. Unusual appearance of renal lymphoma. Clin Radio1 1990; 41: 365-366.
