Atypical kidney tumors and pseudotumors: Imaging features in 44 patients.

Transcription

1 Atypical kidney tumors and pseudotumors: Imaging features in 44 patients. Poster No.: C-1472 Congress: ECR 2011 Type: Scientific Exhibit Authors: M. Kasbi, Y. kallel, M. basly, Z. fitouri, K. Nouira, Y. Nouira ; Tunis/TN, tunis/tn Keywords: Kidney, CT, MR, Contrast agent-intravenous, Tissue characterisation, Neoplasia DOI: /ecr2011/C-1472 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 15

2 Purpose Recognize unusual imaging aspects of some solid kidney tumors. List some imaging signs for differential diagnosis Indications of preoperative percutanous biopsy Methods and Materials A retrospective review of 44 cases of kidney tumors with atypical imaging aspects that lead to preoperative diagnostic errors. These cases were out of an initial sample of 270 cases of nephrectomies for solid renal masses. All patients had a CT urography, 15 had an MR maging because of diagnostic difficulties on CT. Percutanous biopsy was done in two cases (A young patient with an advanced localised solid tumor with enlarge lymph nodes and A diabetic woman with a solid tumor associated to a perinephritis) Results -Preoperative diagnosis was a malignant renal neoplasm in 90% of cases. -Pathology: Page 2 of 15

3 Xanthogranulomatosis7 pyelonephritis Granulosis carcinoma cell 1 Tubulo-papillary carcinoma 12 kidney leiomyosarcoma 1 Sarcomatoid carcinoma 5 Actinomycosis 1 Oncocytoma 2 Malakoplakia 1 Chromophobe carcinoma 6 urothelial carcinoma 1 Epidermoid carcinoma 3 hydatid cyst 2 Bellini Carcinoma Duct 1 haematoma 1 From these 44 cases, demonstrative cases for each pathology will be depicted to show pitfalls in renal mass diagnosis and the need for MRI or even percutanous biopsy in some cases. 1)Tubulo-papillary carcinoma(fig 1 on page 6,2 on page 7,3): on page % of all renal carcinoma Better prognosis that the clear cell carcinoma Hypovascular tumor Calcifications are frequent Limited to the renal cortex without capsular extension in 80%of cases Solid or cystic mass Frequently multiple Hyposignal in T2 weighted MRI (94%) Page 3 of 15

4 2)Sarcomatoid kidney tumor(fig4): on page 8 Rare and very aggressive renal cancer The impact is between 1 and 3% Diagnosis is based on pathologic analysis 3)Bellini duct carcinoma(fig5): on page 8 1% of all kidney tumors Mean age: 59 year old More frequent in male (sex ratio 2/1) Metastasis are frequent at diagnosis ( adenopathy in 80% of cases) Prognosis is poor Imaging features : *Size from 1 to 19cm *Hyperechoic *Poor enhancing in CT *Medullary localisation(94%) *Infiltrative in 65% *Kidney shape is long term preserved *Extension to surrounding organ+++ *Desmoplastic perinephric reaction is frequent *Cystic component in 35% cases *Hyposignal on T2 weighted MRI 4)Leiomyosarcom(fig6): on page 9 The most frequent kidney sarcoma (58%) Developed from (capsular, pelvis of the ureter and vessel) Mean age: 60 Female++(70%) Right kidney ++ It can be shown in Tuberous sclerosis or as an angiomyolipoma degeneration(exception) Calcifications (10%) No specific imaging signs Diagnosis based on pathologic analysis Page 4 of 15

5 5)Oncocytoma(fig7): on page 10 10% of all solid renal mass Could be multifocal (2-12%),bilateral(4-14%) No necrotic nor hemorrhagic component Calcifications are rare Central scar in 35 to 50% (more frequent if tumor size>3cm). The scar enhances in excretory phase Tumor tissue around the scar is homogenous No hemorrhage, no malignancy sign No extension to the perinephric fat Differential diagnosis: Chromophobe cell carcinoma and clear cell carcinoma with central scar 6) Chromophobe carcinoma(fig 8 on page 11,9): on page 11 Inferior to 6% of solid renal mass Mean age: 60 year old Pseudocapsular Central low attenuation suggesting a central scar ( differential diagnosis with oncocytoma) No change in the perinephric structures. No extension to the vessels. Hyposignal in T2 weighted MRI is possible. Better prognosis than clear cell carcinoma. 7)Hydatid cyst(fig10): on page 11 Parasitic infection Infection occurs after ingestion of the dog parasite, Echinococcus granulosus.sheep are the intermediate hosts. 3%affects the kidneys Ultrasonography, CT scans: thick-walled, fluid filled spherical cyst +/- a calcified wall 8)Xanthogranulomatosis Pyelonephritis(Fig 11): on page 12 1% of all renal infections. Females++ (sex ratio 4/1) Mean age :55 year old Exact etiology unknown, usually requires long- term renal obstruction and infection ; Stones +++ (not required for diagnosis) Microscopic feature: lipid laden foamy macrophage accompagnied by inflammatory cells. Differential diagnosis: renal cell carcinoma Page 5 of 15

6 9)Actinomycosis(fig12): on page 13 Chronic granulomatosis suppuration. pathogen: actinomyces. Tumoral syndrome exceptionnally in retroperitoneum ( cervical region++) Preoperative diagnosis is difficult and based upon pathologic analysis. 10)Malakoplakia(fig13): on page 13 Malakoplakia is a rare treatable inflammatory reaction to bacteria, mycobacteria, or fungi that may occur in immunocompromised patients. Usually occurring in the urinary tract, it has also been reported in the lungs. The inflammation is characterized by enlarged, granular macrophages, scattered PMNs, and characteristic concentrically lamellated, calcified structures called Michaelis-Gutman bodies. Recently, a number of cases caused by Rhodococcus equi have been reported in AIDS patients. When to biopsy renal mass? Biopsy aims to determine eventual malignancy of the renal mass. The positive predictive value of imaging findings is so high that a negative biopsy result does not alter management. Renal tumor biopsies are increasingly being used in diagnosis. Biopsy is indicated in: Solid renal tumor with scar and homogenous periscar tissue:suspicion of oncocytoma Suspicion of angiomyolipoma poor in fat Multiple kidney tumors Young patient Suspicion of infectious etiology. Images for this section: Page 6 of 15

7 Fig. 1: Axial unenhanced and contrast-enhanced CT showing a cystic mass in the right kidney with enhancing wall and internal enhancement within the mass: A Bosniak category IV lesion Pathology: Tubulopapillary carcinoma in its cystic form. Fig. 2: Axial enhanced CT image showing 2 masses the upper and lower aspects of the left kidney which enhance since the corticomedullary phase. A nephrectomy was performed and tubulopapillary carcinoma was diagnosed at pathologic analysis of the surgical specimen. This case demonstrate an atypical aspect of the tubulopapillary carcinoma, hypervascular and heterogenous. Page 7 of 15

8 Fig. 3: Axial enhanced and unenhanced CT images showing a right cortical renal mass low enhanced with thrombosis of the right renal vein and inferior vena cava (IVC). The diagnosis of tubulopapillary carcinoma was suspected. An MRI was done showing a hyposignal T2 mass (and the thrombosis of the IVC and the renal vein) which is characteristic of the tubulopapillary carcinoma. Fig. 4: Axial unenhanced and enhanced CT image of 3 patients showing local advanced renal masses with thin calcifications in A, associated to adenomegaly in B and liver metastasis in C. Nephrectomy was performed sarcomtoid tumor was diagnosed at pathologic analysis in the 3 cases. Those cases demonstrate the difficulty to diagnose sarcomatoid tumor based on imaging. Page 8 of 15

9 Fig. 5: Axial unenhanced and contrast-enhanced CT image showing a mass to the mid aspect of the left kidney in the medulla with a partially preserved cortex(arrows). This is an infiltrative mass associated to necrosis adenomegaly and perirenal fat infiltration. The shape and contours are well conserved. A percutanous biopsy diagnosed a Bellini duct carcinoma. Page 9 of 15

10 Fig. 6: A 34 year old man without previous medical history complains of left flank pain and haematuria In the axial contrast-enhanced CT image: left kidney mass in the upper pole extended to the capsular, and the perinephric fat with an heterogenous enhancing. A nephrectomy was performed and the pathologic analysis diagnosed a leiomyosarcoma. Fig. 7: 65 year old woman without previous medical history complained of hepatic colics. An abdominal ultrasonography showed a right renal mass to the upper pole. The unenhanced and enhanced CT in the corticomedullary and excretory phases show an homogenous well limited mass with an early enhancement since the corticomedullary Page 10 of 15

11 phase without central scar or signs of aggressivity. The pathologic analysis diagnosed an oncocytoma. Fig. 8: 60 year old woman complained of flanc pain. The unenhanced and enhanced CT in the cortico medullary and nephrographic phases show an enhanced solid left renal mass in the lower pole, with peripheral vessels and central pseudo scar which suggests an oncocytoma but the heterogenous character around the scar is against this diagnosis. The pathologic analyses diagnosed a chromophobe carcinoma. Fig. 9: Teaching point : In a such tumor(fig 8,9), the heterogenous tissue around the scar becoming homogenous in the excretory phase is suggestive of the chromophobe carcinoma Page 11 of 15

12 Fig. 10: Axial CT unenhanced and contrast enhanced images and axial T2 weighted MR image show a mass with a similar attenuation as the normal renal parenchyma unenhanced in hyposignal T2 weighted MRI with a focal hypersignal.the Ultrasonography showed a hypoechogenic mass without posterior enhancing. A nephrectomy was performed. A hydatid cyst cracked in the urinary tract. Teaching point : Peripheral hyposignal in a such tumor is suggestive of hydatid cyst. Fig. 11: Renal ultrasonography and axial CT unenhanced and enhanced in cortico medullary and excretory image showing heterogenous hypoechoic left renal solid mass in Page 12 of 15

13 the lower pole, with a similar attenuation as the normal parenchyma and totally enhanced in the CT. The enhancement is more important in the periphery. Urinary tract is thin without any lithiasis. Diagnosis:Xanthogranulomatosis pyelonephritis in pseudo-tumor form Fig. 12: 25 year old woman without previous medical history complained of flanc pain. CT scan and angiography performed showing a 9cm right kidney solid mass strongly enhanced with some low attenuation areas. A nephrectomy was performed and renal actinomycosis was diagnosed at pathologic analysis. Fig. 13: 50 years old woman, cirrhotic, complains of right flank pain, without fever. Axial enhanced CT scan images show right medio renal cystic mass contained septa associated to perinephritis signs(arrow)which is suggestive of infectious etiology. Pathology: Renal malakoplakia. Page 13 of 15

14 Conclusion Atypical renal tumors and pseudotumors are an heterogenous group including : Benign tumors: oncocytoma, angiomyolipoma poor in fat... Malignant tumors: Bellini duct carcinoma,chromophobe carcinoma, sarcoma... Pseudotumors:hydatid cyst, malakoplakia, actinomycosis, Xanthogranulomatosis pyelonephritis... Percutanous biopsy is more and more performed. References -Eble JN, Sauter G, Epstein JI, Sesterhenn IA (eds). In: Pathology and genetics of tumours of the urinary system and male genital organs. World Health Organization Classification of Tumours. Lyons: IARC Press, 2004: p. 7. -Israel GM, Bosniak MA. How I do it: evaluating renal masses. Radiology 2005 Aug;236(2): Srigley JR, Delahunt B. Uncommon and recently described renal carcinomas. Mod Pathol 2009 Jun;22:S2-S23. -Watanabe IC, Billis A, Guimarães MS, Alvarenga M, de Matos AC, Cardinalli IA, Filippi RZ, de Castro MG, Suzigan S. Renal medullary carcinoma: report of seven cases from Brazil. Mod Pathol 2007 Page 14 of 15

15 Sep;20(9): Traité de Radiodiagnostic V - Urologie-Gynécologie : A-10 (1990) -Schmidbauer J, Remzi M, Memarsadeghi M, Haitel A, Klingler HC, Katzenbeisser D, Wiener H, Marberger M. Diagnostic accuracy of computed tomography-guided percutaneous biopsy of renal masses. Eur Urol 2008 May;53(5): Personal Information Page 15 of 15