By

Ahmed Nabeel Mohamed

Overview: Definition.

Incidence.

Presentation.

Diagnosis.

Treatment.

Definition: The most common soft tissue sarcoma of adult life.

Malignant neoplasm of uncertain origin that arises

both in soft tissue and bone.

The precise origin of MFH cells has been disputed.

In 2002, the World Health Organization (WHO)

renamed it as an undifferentiated pleomorphic

sarcoma.

Epidemiology: Rarely occurs in the bone.

Males are affected more often than females (9:4).

MFH occurs most commonly in the extremities (70-75%) with lower extremities accounting for 60% of cases), followed by the retroperitoneum.

Commonly in the metaphysis of long bones such as femur and tibia.

Accounts for 10% to 20 % of all soft tissue malignant neoplasms.

CLASSIFICATION

Five subtypes of MFH are present, These are:

(1) Storiform pleomorphic.

(2) Myxoid.

(3) Inflammatory.

(4) Giant cell.

(5) Angiomatoid.

Gross picture: • MFH is a lobulated, fleshy, gray

white mass.

• There may be yellow areas of

lipid or darker areas of

hemorrhage.

• The mass may be all soft tissue

or have intra-osseous extension.

• The margins of the tumor are

normally ill defined and

destructive.

Microscopic picture:

• In all forms, there are fibroblast and

histiocyte elements in some ratio.

• Calcifications are formed by reactive

periosteal cells and are not produced by

tumor cells, which help to differentiate the

tumor from fibrosarcoma.

Inflammatory

malignant fibrous

histiocytoma

5% of cases

Myxoid malignant

fibrous histiocytoma

10%-20% of cases

The storiform-

pleomorphic MFH

60-70% of cases

Nomenclature and Categorization of Malignant Fibrous Histiocytoma

(MFH) Subtypes (2002 World Health Organization Classification)

Old Nomenclature of

MFH Subtype

Current Nomenclature of

MFH Subtype Tumor Category

Storiform-pleomorphic

MFH

Undifferentiated high-

grade pleomorphic

sarcoma

Fibrohistiocytic

Myxoid MFH Myxofibrosarcoma Myofibroblastic

Giant cell MFH

Undifferentiated

pleomorphic sarcoma

with giant cells

Fibrohistiocytic

Inflammatory MFH

Undifferentiated

pleomorphic sarcoma

with prominent

inflammation

Fibrohistiocytic

Angiomatoid MFH Angiomatoid fibrous

histiocytoma

Tumors of uncertain

differentiation

Symptoms and Presentation: Patients often complain of

a rapidly enlarging mass or lump .

Usually painless unless it is compressing a nearby nerve.

weight loss and fatigue are not typical .

Imaging: As with other soft-tissue tumors, MRI is the imaging

method of choice.

CT scanning is also useful for evaluation of calcifications.

MFH usually presents with a soft tissue mass with or without cortical erosion.

There is no periosteal reaction.

x-ray : Plays a key role in establishing the initial diagnosis of bone

tumors.

Advantages: helps to detect

1. Margins.

2. Cortical Expansion.

3. Periosteal Reaction.

4. Matrix and Tumor Mineralization.

Computed Tomography:

CT may be used to evaluate potential internal matrix and/or cortical erosion.

Magnetic Resonance Imaging:

As with other soft-tissue tumors, MRI is the imaging method of choice.

Many other techniques can helps the diagnosis as:

Biopsy.

Immunohistochemistry.

Electron Microscopy.

Molecular Techniques.

Cytology.

Nuclear Imaging.

Angiography.

Biopsy The definitive diagnostic test for tumors.

Fine needle aspiration biopsy.

Core needle biopsy.

Open biopsy:

Incisional biopsies.

Excisional biopsies.

The recommendations of succesful biopsy: It is not a simple procedure.

Pay as close attention to asepsis, skin preparation, haemostasis, wound closure and so on as with any other operation.

Avoid transverse incisions.

CT-guided biopsy offers an additional advantage as it has an overall accuracy of 80%.

Differential diagnosis: Synovial sarcoma.

Aggressive fibromatosis.

Lytic metastasis.

Soft tissue metastases.

Myositis ossificans.

Benign fibrous histiocytoma.

There are essentially three main types of treatment that will need to be coordinated to treat the MFH: 1. Surgery.

2. Radiation.

3. Chemotherapy.

Staging:

The American Joint Committee on Cancer (AJCC) Staging System for Soft Tissue Sarcoma, 6th Edition

Stage Size Depth Grade Metastases

I Any Any Low No

II

< 5cm, any

depth OR >

5cm

Superficial High No

III > 5cm Deep High No

IV Any Any Any Yes

Surgery: Surgery is the cornerstone of treatment for all soft

tissue sarcomas.

Historically, soft tissue sarcomas were treated with

amputation.

Currently at least 90% of tumors are now removed

using limb-sparing surgery .

Classification of surgical resections for the treatment of sarcoma .

Intralesional Partial removal of the tumor

Marginal Through the reactive zone; may leave

residual microscopic disease

Wide Entire tumor removed with a cuff of

normal tissue

Radical Entire compartment containing the

tumor removed

Intraoperative image demonstrates a posterior approach to the calf for removal of a malignant fibrous histiocytoma. Neurovascular dissection and wide excision of the mass.

Radiation therapy : The purpose of it is to improve local tumor control

by killing residual microscopic disease.

Pre-operative radiation can potentially shrink the

tumor, making limb-sparing surgery possible or

easier but not commonly used.

Post-operative radiation is probably the most

commonly used modality.

The advantages and disadvantages of the timing of

radiation therapy: Delivery Method Advantages Disadvantages

Pre-operative 1. Potentially shrinks

tumor

2. Smaller volume required

1. Increase in wound

complications

2. Delay in definitive surgery

Intra-operative

1. Can concentrate very

high doses to close

margins

2. Minimal injury to

normal tissue

1. Requires a special

operating room with

exposure to O.R. staff

2. Wound complications

Post-operative 1. Fewer wound

complications

2. Immediate surgery

1. Larger volume required

secondary to operative

contamination.

2. Second sarcoma .

Chemotherapy: Is often incorporated into the treatment of patients

with distant recurrence.

One of the major limitations of chemotherapy is the

associated toxicities with the doses necessary to

have a significant impact on disease-specific

survival.

The role of chemotherapy in the treatment of MFH is

not entirely clear.

PROGNOSIS: Tumor grade, size, and presence of distant

metastases, are the most important prognostic factors.

The 5 year survival estimates range from 34% to 60%.

Local recurrence (LR), recurrence of the tumor in the

same location, will occur in approximately 20-30% of all

patients with soft tissue sarcomas.

MFH is a curable disease if early diagnosed.

"Malignant Fibrous Histiocytoma" has been changed by the WHO to Undifferentiated Pleomorphic Sarcoma “UPS”.

surgical excision most often supplemented with adjuvant radiation therapy.