Soft tissues lymphoma, the great pretender. MRI diagnostic keys.

Transcription

1 Soft tissues lymphoma, the great pretender. MRI diagnostic keys. Poster No.: C-2133 Congress: ECR 2015 Type: Educational Exhibit Authors: L. Caminero, M. E. Banegas Illescas, M. L. Rozas, M. Y. Torres, A. Pinar, J. A. Villanueva; Ciudad Real/ES Keywords: DOI: Lymphoma, Imaging sequences, MR, Oncology, Musculoskeletal soft tissue /ecr2015/C-2133 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 8

2 Learning objectives To review the MRI features of soft tissues lymphoma. To compare our findings with the description in medical literature. To describe the features and specific findings that can help us to diagnose them. Background Primary involvement by a lymphomatous muscular mass is very infrequent. When there is a soft tissue mass, the more probable diagnosis is sarcoma. In a ten years period of time, from soft tissue tumors, about 500 of them were primary lymphomas. It is about 0'3% of all Hodgkin lymphomas and 1'5% of non Hodgkin lymphomas. The more involved locations are the thigh and the superior part of the arm, It is important to include lymphoma in the differential diagnosis of soft tissue masses because with a difference to other soft tissue mass it responds to chemotherapy and or radiation therapy. CT is useful to evaluate these patients, because the findings are unspecific presenting as masses with a similar density as muscle with high homogeneous contrast enhancement. MRI is the election technique for diagnosis and the published series of patients (not very numerous) are based on their findings. Generally speaking, it is known its behavior in T1 and T2 and fat saturation sequences, enhancement with contrast pattern, skin involvement and subcutaneous fat and its extension through all the different compartments. Radiological findings are generally unspecific, and the most frequently described in the published series are a soft tissue mass with intermediate signal intensity in T2, moderately hyper-intense to muscle in T1, and that involves more than one muscular compartment (in several series the multiple compartment involvement is up to 50%). Another feature is the extension following the neurovascular bundle that will correspond with lymphatics dissemination and is infrequent in sarcomas. It can also present as an increase in size of a muscle with preservation of the fat planes and extension through the muscular fascicles. The enhancement pattern is unspecific because in the published series were both homogeneous and heterogenous enhancement patterns. Page 2 of 8

3 In previous studies the T2 behavior has been discrepant because some had the fat as reference while others used the muscle, and another reason was the use of SE (spinecho) sequences by some of them while others used FSE (fast spin-echo), because in some cases using T2 FSE will give a more hyper-intense behavior than using SE sequences. In MRI, the findings that will lead us to lymphoma are a enlarged involved muscular segment, extension following the neurovascular bundle, multiple compartment involvement, subcutaneous stranding and skin thickening, all of them more unusual features in other malignant soft tissue tumors. Findings and procedure details We perform a radiopathological correlation of the findings found in the reviewed literature, and the cases of our department in the last year (from december 2013 to november 2014) making a special emphasis in those findings that are diagnostic keys. CASE 1 (Fig. 1 on page 3) Follicular lymphoma grade 2. CASE 2 (Fig. 2 on page 4) Diffuse large B-cell lymphoma. CASE 3 (Fig. 3 on page 5) Diffuse large B-cell lymphoma. This case (case 3) presents the most concordant findings with the literature because we can see a wide soft tissue segment involved, the signal behavior in all the sequences, the pancompartmental involvement and histologic type (diffuse large B-cell lymphoma), that is the most frequently described. Images for this section: Page 3 of 8

4 Fig. 1 Page 4 of 8

5 Fig. 2 Page 5 of 8

6 Fig. 3 Page 6 of 8

7 Conclusion Lymphomatous primary muscle involvement is an unfrequent entity that may not be in our mind when we make the differential diagnosis. The MRI features are very unspecific and by its frequency they can be mistaken with other soft tissue tumors. However, it is very important to take it into account in the differential diagnosis because the management and prognosis is very different. Generally speaking, the behavior is unspecific but, in some cases, certain findings are more frequent in soft tissue lymphomas, that can lead to the diagnosis. Personal information References 1. MRI Features of Skeletal Muscle Lymphoma. Chang Woo Chun, Won-Hee Jee Hye Jung Park, Yeo Joo Kim, Jeong-Mi Park, Sang-Hoon Lee, Sung-Hwan Park. AJR 2010; 195: Suresh S, Saifuddin A, O'Donnell P. Lymphoma presenting as musculoskeletal soft tissue mass: MRI findings in 24 cases. Eur Radiol 2008; 18: Hwang S. Imaging of lymphoma of the musculoskeletal system. Radiol Clin North Am 2008; 46: Lee VS, Martinez S, Coleman RE. Primary muscle lymphoma: clinical and imaging findings. Radiology 1997; 203: Metzler JP, Fleckenstein JL, Vuitch F, Frenkel EP (1992) Skeletal muscle lymphoma: MRI evaluation. Magn Reson Imaging 10: Eustace S, Winalski CS, McGowen A, Lan H, Dorfman D (1996) Skeletal Page 7 of 8

8 muscle lymphoma: observations at MR imaging. Skeletal Radiol 25: Page 8 of 8