HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: 2241011113v1 224/1/99    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kransdorf, M. J. Articles by Temple, H. T. Search for Related Content PubMed PubMed Citation Articles by Kransdorf, M. J. Articles by Temple, H. T.

Imaging of Fatty Tumors: Distinction of Lipoma and Well-differentiated Liposarcoma¹

¹ From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224-3899 (M.J.K., L.W.B., J.J.P.); Department of Radiologic Pathology, Armed Forces Institute of Pathology, Walter Reed Army Medical Center, Washington, DC (M.J.K., M.D.M.); Department of Radiology and Nuclear Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md (M.D.M.); Department of Radiology, University of Maryland School of Medicine, Baltimore (M.D.M.); Department of Orthopedic Surgery, Medical College of Virginia, Virginia Commonwealth University, Richmond (W.C.F.); and Department of Orthopedics and Rehabilitation, University of Miami School of Medicine, Fla (H.T.T.). Received June 26, 2001; revision requested August 16; final revision received January 4, 2002; accepted January 23. Address correspondence to M.J.K. (e-mail: kransdorf.mark@mayo .edu).

PURPOSE: To review the reliability of computed tomographic (CT) and magnetic resonance (MR) imaging features in distinguishing lipoma and well-differentiated liposarcoma.

MATERIALS AND METHODS: CT (n= 29) and MR (n = 40) images and radiographs (n = 28) of 60 patients with histologically verified fatty tumors (35 lipomas and 25 well-differentiated liposarcomas) were retrospectively reviewed in 31 females and 29 males (mean age, 56 years; age range, 1-88 years). Images were assessed for adipose tissue content, and nonfatty component was classified (thin and/or thick septa and nodular and/or globular components) as absent, mild, moderate, or pronounced. Also assessed were signal intensity and tissue attenuation of the fatty components and nonadipose elements.

RESULTS: Statistically significant imaging features favoring a diagnosis of liposarcoma included lesion larger than 10 cm (P < .001), presence of thick septa (P = .001), presence of globular and/or nodular nonadipose areas (P = .003) or masses (P = .001), and lesion less than 75% fat (P < .001). The most statistically significant radiologic predictors of malignancy were male sex, presence of thick septa, and associated nonadipose masses, which increased the likelihood of malignancy by 13-, nine-, and 32-fold, respectively. Both lipoma and liposarcoma demonstrated thin septa and regions of increased signal intensity on fluid-sensitive MR images.

CONCLUSION: A significant number of lipomas will have prominent nonadipose areas and will demonstrate an imaging appearance traditionally ascribed to well-differentiated liposarcoma. Features that suggest malignancy include increased patient age, large lesion size, presence of thick septa, presence of nodular and/or globular or nonadipose masslike areas, and decreased percentage of fat composition.

© RSNA, 2002

Index terms: Lipoma and lipomatosis, 40.363 • Lipoma and lipomatosis, CT, 40.1211 • Lipoma and lipomatosis, MR, 40.1214 • Liposarcoma, 40.371 • Liposarcoma, CT, 40.1211 • Liposarcoma, MR, 40.1214 • Soft tissues, neoplasms, 40.363, 40.371

This article has been cited by other articles:

				Pathology Quiz Case 2: Diagnosis Arch Otolaryngol Head Neck Surg, September 1, 2008; 134(9): 1014 - 1015. [Full Text] [PDF]

				H. Sakurai, M. Kaji, K. Yamazaki, and K. Suemasu Intrathoracic lipomas: their clinicopathological behaviors are not as straightforward as expected. Ann. Thorac. Surg., July 1, 2008; 86(1): 261 - 265. [Abstract] [Full Text] [PDF]

				S Chakraborty, E E Kassel, and E Yu Nasopharyngeal liposarcoma MRI imaging features and a review of the literature Br. J. Radiol., July 1, 2007; 80(955): e145 - e146. [Abstract] [Full Text] [PDF]

				P O'Sullivan, H O'Dwyer, J Flint, P L Munk, and N Muller Soft tissue tumours and mass-like lesions of the chest wall: a pictorial review of CT and MR findings Br. J. Radiol., July 1, 2007; 80(955): 574 - 580. [Abstract] [Full Text] [PDF]

				I-C Chiang, M-Y Jang, K-B Tsai, and T-J Hsieh Huge renal lipoma with prominent hypervascular non-adipose elements. Br. J. Radiol., October 1, 2006; 79(946): e148 - e151. [Abstract] [Full Text] [PDF]

				M. Hoshi, S. Matsumoto, J. Manabe, T. Tanizawa, T. Shigemitsu, H. Koyanagi, K. Ae, K. Takeuchi, and N. Kawaguchi Surgery for dedifferentiated liposarcoma, presenting two radiologically and pathologically distinctive patterns. Jpn. J. Clin. Oncol., July 1, 2006; 36(7): 462 - 467. [Abstract] [Full Text] [PDF]

				M. D. Murphey, L. K. Arcara, and J. Fanburg-Smith From the Archives of the AFIP: Imaging of Musculoskeletal Liposarcoma with Radiologic-Pathologic Correlation RadioGraphics, September 1, 2005; 25(5): 1371 - 1395. [Abstract] [Full Text] [PDF]

				M. A. Zamora, C. A. Zamora, E. A. Samayoa, H. A. Morales, and J. F. Ceballos High-Resolution Ultrasonography in an Aggressive Thenar Intramuscular Lipoma J. Ultrasound Med., August 1, 2005; 24(8): 1151 - 1155. [Full Text] [PDF]

				D. A. Torigian and E. S. Siegelman CT Findings of Pelvic Lipomatosis of Nerve Am. J. Roentgenol., March 1, 2005; 184(3_supp): S94 - S96. [Full Text] [PDF]

				A. Lopez Soriano, A. Tomasello, P. Luburich, and A. Noel Fat Necrosis in a Chest Wall Lipoma Am. J. Roentgenol., September 1, 2004; 183(3): 866 - 866. [Full Text] [PDF]

				M. D. Murphey, J. F. Carroll, D. J. Flemming, T. L. Pope, F. H. Gannon, and M. J. Kransdorf From the Archives of the AFIP: Benign Musculoskeletal Lipomatous Lesions RadioGraphics, September 1, 2004; 24(5): 1433 - 1466. [Abstract] [Full Text] [PDF]

				E. E. O'Connor, L. B. Dixon, T. Peabody, and G. S. Stacy MRI of Cystic and Soft-Tissue Masses of the Shoulder Joint Am. J. Roentgenol., July 1, 2004; 183(1): 39 - 47. [Full Text] [PDF]

				C. M. Gaskin and C. A. Helms Lipomas, Lipoma Variants, and Well-Differentiated Liposarcomas (Atypical Lipomas): Results of MRI Evaluations of 126 Consecutive Fatty Masses Am. J. Roentgenol., March 1, 2004; 182(3): 733 - 739. [Abstract] [Full Text] [PDF]

				L. P. Chan, R. Gee, C. Keogh, and P. L. Munk Imaging Features of Fat Necrosis Am. J. Roentgenol., October 1, 2003; 181(4): 955 - 959. [Abstract] [Full Text] [PDF]

				T. Ohguri, T. Aoki, M. Hisaoka, H. Watanabe, K. Nakamura, H. Hashimoto, T. Nakamura, and H. Nakata Differential Diagnosis of Benign Peripheral Lipoma from Well-Differentiated Liposarcoma on MR Imaging: Is Comparison of Margins and Internal Characteristics Useful? Am. J. Roentgenol., June 1, 2003; 180(6): 1689 - 1694. [Abstract] [Full Text] [PDF]