Malignant Fibrous Histiocytoma of Bone

  • Metaphysis or diaphysis of long bones, especially around the knee.

  • Femur, tibia, and humerus are, in this order, the more frequent locations.

  • Pelvis, especially the ilium, follows in frequency.

  • About any other bone can be more rarely affected.

Clinical Symptoms and Signs

  • Local pain and/or the presence of a mass is the initial symptom that can present as early as 1 week to several months.

  • Pathologic fracture may occur.

  • As this tumor is frequently associated to a preceding disease, there may be symptoms related to the primary condition.

Image Diagnosis

Radiographic and CT Features

  • Radiographic and CT findings correspond to a high-grade malignant lesion usually located in the metaphysis or diaphysis of a long bone.

  • Lytic, with no mineral deposits or ossification, poorly circumscribed, with early cortical destruction and extension to soft parts.

  • Periosteal reaction is unusual.

  • Evidence of a preceding disorder may be seen.

MRI Features

  • MRI shows a lesion hypo- or isointense to muscle on T1-weighted images, high signal intensity on T2, and contrast enhancement, especially at the periphery of the tumor.

Bone Scan

  • Bone scan demonstrates a hot lesion.

Image Differential Diagnosis

Osteosarcoma, in Young Patients

  • In the absence of discernible mineralized tissue, it may be impossible to differentiate by image methods.

All the following tumors may also present very similar imaging features when a single lesion is considered:

  • Fibrosarcoma, high grade

  • Leiomyosarcoma, high grade

  • Angiosarcoma

  • Malignant primary lymphoma of the bone

  • Metastatic carcinoma

  • Myeloma

  • Signals of a preexisting lesion can suggest the diagnosis of MFH.

  • Presence of multiple lesions can suggest metastasis or myeloma, which have to be screened clinically.


Gross Features

  • Usually a large lesion with undefined limits either intramedullary or in its eventual soft tissue extension.

  • Its cut surface varies from white and fibrous (collagen producing areas) to soft (cellular areas) to tan and yellowish (lipid-laden areas) to hemorrhagic and friable (necrotic areas).

Histological Features

  • Histologically, MFH is characterized by a mixed population of spindle cells, histiocytic-like cells, multinucleated giant cells, all of which, including the giant cells, may be very atypical, and a chronic inflammatory infiltrate.

  • Specific kinds of cells may predominate in certain areas.

  • Spindle cell areas present a storiform or cartwheel pattern.

  • Histiocytic-like cells may predominate, with large clear cytoplasm and atypical nuclei.

  • Atypical mitoses are frequent.

  • Some areas may be richly vascularized, sometimes in a hemangiopericytoma-like pattern.

  • Foci of inflammatory infiltration are a common finding.

  • Giant multinucleated very bizarre cells are seen and may be abundant.

  • Areas with a myxoid background may be seen.

  • In certain tumors, the presence of intercellular hyalinized collagen matrix may be impossible to tell from osteoid. Extensive sampling may be necessary to rule out this possibility.

Pathology Differential Diagnosis


  • Always contains neoplastic bone trabeculae that must be sought extensively; may present nuclear positivity with SATB2.

Fibrosarcoma, High Grade

  • Absolute predominance of spindle cell population

Both differential diagnosis cited above may not be of clinical importance, since these tumors will probably be treated the same way.

Liposarcoma, Pleomorphic Type

  • Because of the foamy aspect of some neoplastic cells

Leiomyosarcoma, High Grade

  • Immunohistochemical methods may be necessary in difficult cases.

Metastatic Sarcomatoid Carcinoma

  • Clinical and immunohistochemical methods may identify a renal tumor and characteristic immunophenotype.

Malignant Lymphoma with Fibrosis

  • Look for eventual multicentricity.

  • Spindle cells are not atypical.

Jan 2, 2017 | Posted by in ORTHOPEDIC | Comments Off on Malignant Fibrous Histiocytoma of Bone
Premium Wordpress Themes by UFO Themes