SPETRUM OF ABDOMINAL IMAGING FINDINGS IN TUBEROUS SCLEROSIS: The common and uncommon manifestations.

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1 SPETRUM OF ABDOMINAL IMAGING FINDINGS IN TUBEROUS SCLEROSIS: The common and uncommon manifestations. Poster No.: C-925 Congress: ECR 204 Type: Educational Exhibit Authors: J. B. Dutra, A. F. D. Melo, E. J. Silva, B. C. B. D. Silva, T. M. 2 2 Guedes, M. V. N. D. O. Pontual, J. Elias Jr, V. F. Muglia, S. 3 2 Cavalcanti de Albuquerque ; Recife, Pernambuco/, Ribeirão 3 Prêto/, Recife/ Keywords: Abdomen, Kidney, CT, MR, Education, Congenital, Education and training DOI: 0.594/ecr204/C-925 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 of 0

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3 Learning objectives To illustrate the imaging findings of the abdominal involvement from tuberous sclerosis, including MRI and TC. To discuss the differential diagnosis of abdominal manifestations of TS. Background TS is a rare neurocutaneous syndrome caused by mutations of two genes known as TSC and TSC2. TS can affect both sexes and all ethnic groups. The estimated prevalence ranges from one in 6000 to one in [], and approximately two-thirds of the cases are sporadic [2]. Its classical clinical presentation is a triad of multiples sebaceum adenoma, epilepsy and mental retardation, however all those clinical findings together in a patient with TS is not so common. Imaging exams can play an important role in the diagnosis of TS and the knowledge of common and uncommon abdominal presentations of TS helps the radiologist to suggest a correct diagnosis based on image features. One of the most common abdominal manifestation is renal angiomyolipoma (AML), with a frequency of 55%-75% [3]. They are characterized by their fat containing cells (not always seen on image study), with variable amounts of abnormal vessels and immature smoothmuscle cells. The majority of AMLs are asymptomatic and also incidentally discovered [4]. Renal cysts or polycystic kidney disease can develop in patients with TS and it is more common in younger children [5]. Generally asymptomatic, they are more associated with arterial hypertension and renal failure than renal AMLs [6]. Renal malignant tumors can occur in young patients with TS. However, the overall incidence of renal cell carcinomas in patients with TS is the same of general population [7]. A variety of hepatobiliary lesions have been described in patients with TS, including hepatomegaly, AMLs, hamartomas, and fibromas [4]. Page 3 of 0

4 Common manifestations of gastrointestinal involvement include polyps, which are frequently multiple and can occur anywhere from the esophagus to the rectum. Some gastrointestinal polyps show early malignant change [5,6]. Finding on gastrointestinal system also include lymphangioleiomyomatosis (LAM) of the large bowel and hamartoma. Findings and procedure details Diagnosis of AML on computed tomography (CT) is based on the demonstration of the presence of intratumoral fat. Typical CT findings of AMLs are noncalcified tumors containing fat demonstrated by attenuation coefficient of less than -20 HU [8] (Figure ). Although unenhanced CT with thin sections is useful for detecting small amounts of fat, intratumoral fat may not be detected. Most of the cases of hepatic AML are sporadic, but when it is associated with renal AML TS must be in the differential diagnosis [4]. Page 4 of 0

5 Fig. : Unenhaced CT demonstrates well-defined hypoattenuating nodular density liver images on axial CT (A, blue arrows) with fat containing (B), suggestive of angiomyolipoma. Elastin-poor vascular structures in angiomyolipomas make these vascular lesions prone to aneurysm formation and hemorrhage. Aneurysm formation may be a predictor of rupture and may therefore provide useful information in the care of patients with angiomyolipoma[9] (figure 02). Fig. 2: Arteriography shows small saccular aneurysms that may occur in AML. Renal AML may become clinically problematic because differentiating them from renal cell carcinomas sometimes is difficult or even impossible. Clear cell carcinoma demonstrates heterogeneous enhancement and early washout at contrasted CT, while chromophobe renal cell carcinomas have weak enhancement and Page 5 of 0

6 early washout [4]. Papillary carcinomas tend to exhibit gradual enhancement, a finding that may be seen in AMLs with minimal fat [4]. Tumors that have hyperattenuation at unenhanced CT, homogeneous enhancement and hypointensity on T2-weighted magnetic resonance images (MRI) are more probably AML with minimal fat than a carcinoma [0,] (figure 03). Fig. 3: Solid lesion (blue arrows) in the right kidney on axial unenhanced CT (A) and post-contrast (B) shows enhancement of the lesion without a visible fat content. Volumetric T-weighted gradient-eco MRI sequence with fat suppression before (C) and post-contrast - late phase - (D) confirm the CT findings and shown no early wash-out. Coronal T2 (E) shows hypointensity of the lesion and diffusion weighted sequence (F) demonstrates restricted diffusion. That lesion has slow growth according to previous exams and may correspond to a angiomyolipoma poor in fat, but a renal cell carcinoma with low growth can not be excluded by imaging only. Bilateral multiple renal cysts in younger patients are another manifestations of tuberous sclerosis and they are well demonstrated on MRI by their hyperintensity on T2 (figure 04). Page 6 of 0

7 Fig. 4: Axial MRI SPIR T2-weighted (A) and gradient-eco T-weighted (B) show multiple renal cysts (blue arrows), characterized by their high signal intensity on T2 and low signal intensity on T. Patients with TS may show colonic masses extending into the mesentery that may correspond to LAM or hamartomas (figure 05). When in the lungs (figure 06), LAM is recognized as a diffuse interstitial proliferation of smooth muscle cells with cystic changes associated, usually presenting in women. Hamartomas are non-malignant lesions composed of tissue elements normally found in the place of its origin, but with a disorganized growth. Page 7 of 0

8 Fig. 5: Volumetric T-weighted gradient-eco MRI sequence with fat suppression before (A) and after (B) the infusion of gadolinium demonstrate aneurysmal dilatation of the ascending colon with diffuse wall thickening and heterogeneous enhancement (blue arrows). Unenhanced CT (C, D) shows calcifications (blue stars) and expansion of the mesentery. In this case colonic hamartoma is a possible diagnosis, having LAM as a differential diagnosis. Page 8 of 0

9 Fig. 6: CT scan shows multiple lung cysts (blue arrows) distributed randomly with welldefined thin walls in a young woman with TS, compatible with pulmonary LAM. Conclusion Awareness of common and uncommon imaging features of TS in the abdomen allow the radiologist to be more effective in early diagnosis of conditions associated with this disease. Personal information References Page 9 of 0

10 [] Baron Y, Barkovich AJ. MR imaging of tuberous sclerosis in neonates and young infants. AJNR Am J Neuroradiol 999;20: [2] Narayanan V. Tuberous sclerosis complex: genetics to pathogenesis. Pediatr Neurol 2003;29: [3] Crino PB, Nathanson KL, Henske EP. The tuberous sclerosis complex. N Engl J Med 2006;355: [4] Umeoka S, Koyama T, Miki Y, Akai M, Tsutsui K, Togashi K. Pictorial review of tuberous sclerosis in various organs. Radiographics Nov-Dec;28(7):e32. doi:0.48/rg.e32. Epub 2008 Sep 4. Review. PubMed PMID: [5] Leung AK, Robson WL. Tuberous sclerosis complex: a review. J Pediatr Health Care 2007;2:08-4. [6] Crino PB, Nathanson KL, Henske EP. The tuberous sclerosis complex. N Engl J Med 2006;355: [7] Tello R, Blickman JG, Buonomo C, Herrin J. Meta analysis of the relationship between tuberous sclerosis complex and renal cell carcinoma. Eur J Radiol 998;27:3-38. [8] Logue LG, Acker RE, Sienko AE. Best cases from the AFIP: angiomyolipomas in tuberous sclerosis. Radiographics 2003;23: [9] Yamakado K, Tanaka N, Nakagawa T, Kobayashi S, Yanagawa M, Takeda K. Renal angiomyolipoma: relationships between tumor size, aneurysm formation, and rupture. Radiology Oct;225(): PubMed PMID: [0] Jinzaki M, Silverman SG, Tanimoto A, Shinmoto H, Kuribayashi S. Angiomyolipomas that do not contain fat attenuation at unenhanced CT (letter). Radiology 2005;234:3;author reply [] Jinzaki M, Tanimoto A, Narimatsu Y, et al. Angiomyolipoma: imaging findings in lesions with minimal fat. Radiology 997;205: Page 0 of 0