IS Case 161: Malignant fibrous histiocytoma

Jerry Lee, MD

Imaging Sciences URMC 2008
Publication Date: 2009-05-21


Patient is a 60-year-old female with enlarging bump along the lateral aspect of her right lower leg.


Soft tissue mass located in the right lower extremity predominantly in the subcutaneous fat demonstrates T1 low-signal, T2 high-signal and enhancement on post-contrast imaging.


Malignant fibrous histiocytoma (MFH) is a pleomorphic sarcoma, occurring most frequently in the deep soft tissues of the extremities (70-75%), with about 15% of lesions arising in the retroperitoneal space and its organs, 5% in the head and neck, and 5-10% in other locations. The age range is from 10-90 years with a peak of 50 years more commonly in males. Primary osseous MFH is less common. MFH is the most common soft-tissue sarcoma of late adult life and accounts for 20-30% of all soft-tissue sarcomas. There are 5 different histiologic types with the most common being storiform/pleomorphic type. The others are myxoid, giant cell, inflammatory, and angiomatoid types. The most common clinical presentation is an enlarging painless soft tissue mass in the thigh, typically 5-10 cm in diameter. Two-thirds of tumors are intramuscular. The clinical stage of the tumor, which is defined by tumor grade, size, and presence of distant metastases, is the most important prognostic factor. Distant metastasis most commonly occurs to the lung (90%), bone (8%), and liver (1%).

Radiologic findings on MRI are nonspecific, however classically include low- to intermediate-signal on T1 sequences and high-signal intensity on T2 sequences. There is classically nodular enhancement on post-contrast imaging. A pseudocapsule can also be defined. On plain film and CT areas of calcification can also be seen. Hemorrhage is an important finding if identified and should raise the suspicion of MFH.


  1. Murphey MD, Gross TM, Rosenthal HG. From the archives of the AFIP. Musculoskeletal malignant fibrous histiocytoma: Radiologic-pathologic correlation. Radiographics. 1994 Jul;14(4):807-26; quiz 827-8. [PMID: 7938770]

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