Fibromatosis

The term 'Fibromatosis' was intoduced for the first time by Arthur Purdy Stout.
Fibromatosis includes a broad group of related fibrous lesions . The term fibromatosis refers to a group of benign soft tissue tumors (fibromas), which have certain characteristics in common, including absence of cytologic and clinical malignant features, a histology consistent with proliferation of well-differentiated fibroblasts, an infiltrative growth pattern, and aggressive clinical behavior with frequent local recurrence.

Salient Features:

1. Macroscopically, cut surface is usually pale, whorled and fibrous with irregular margin.
2. Microscopically,  there is proliferation of palely eosinophilic fibroblasts and myofibroblasts.   
3. Infiltrative pattern
4. Presence of abundant collagen between the tumour cells.
5. Absence of cytological features of malignancy.
6. Cellularity and mitotic activity are extremely variable.
7. Other light microscopic features include:
    i.   thick-walled blood vessels sharply outlined from surrounding tissue.
    ii.  perivascular lymphocytic infiltrate at the advancing edge of the tumour.
    iii. rarely metaplastic ossification or cartilage formation.
8. Immunohistochemistry: Vimentin -Positive; Variably positivity for SMA, CD117 & desmin ; CD34 - Negative.  Staining correlates with the cellularity.
9. Aggressive clinical behaviour characterized  by repeated local recurrences. There is no evidence of metastasis.
10. Ultrastructural study confirms fibroblastic and myofibroblastic features. Presence of intracytoplasmic collagen formation has been described.

Fibromatosis is subdivided into two major groups: 

I  Superficial (fascial) fibromatoses: 

Features: 1. Slow growing tumour ; 2. Small size ;  3. Arise from fascia or aponeurosis ;   4. Less aggressive.

A. Palmar fibromatosis (Dupuytren's contracture)
B. Plantar fibromatosis (Ledderhose's disease)
C. Penile fibromatosis (Peyronie's diseasee)
D. Knucle pads

II  Deep (musculoaponeurotic) fibromatoses:

Features: 1. Rapidly growing tumour ;  2. Usually attain large size ;  3. Involve deeper structures (musculature of trunk and the extremities).

A. Extraabdominal fibromatosis (extraabdominal desmoid)
B. Abdominal fibromatosis (abdominal desmoid)
C. Intraabdominal fibromatosis (intraabdominal desmoid)
            1. Pelvic fibromatosis
            2. Mesenteric fibromatosis
            3. Gardner's syndrome (Familial adenomatous polyposis)

Desmoid tumor can be defined as a pseudoencapsulated infiltrative growth of well-differentiated collagenous fibroblasts and fibrocytes arising either in fascia or musculoaponeurotic structures.

The etiology of desmoid tumors is poorly defined. The most commonly implicated etiologic factors are trauma, hormonal disturbances, and genetic or hereditary factors.

Desmoid tumours of the anterior abdominal wall are much less common than extra-abdominal desmoids.

They may occur at any age but are most common in the third and fourth decades.

Although both sexes may be affected, abdominal desmoids predominate in females, particularly in females of childbearing age.

Extra-abdominal desmoids, which most commonly occur on the back, chest wall, head and neck, or lower extremity, have a male predominance.

Most patients complain of a painless mass of several months or years' duration.

The microscopic picture is variable and generally corresponds to the patient's age. The pattern usually found in the older child exhibits moderate cellular fibrous tissue with an intertwining fascicular pattern. Less cellular examples of the tumour are associated with larger amounts of collagen and are encountered in older subjects.

The primary consideration in surgical treatment of desmoid tumours should be the prevention of local recurrence.

In most instances, this can be achieved by wide local excision or muscle group resection.

Recurrence after surgery is well recognized and tumour recurrence as late as 5 and 10 years after initial surgery has been documented.

Desmoplastic fibroma of bone is considered the osseous counterpart of the soft tissue desmoid tumour.

Differential Diagnosis:

Gastrointestinal Stromal Tumour:

Gross features:

GIST: Soft and lobulated with hemorrhage, necrosis, or cystification.

Intra-abdominal fibromatosis: firm, tan and homogenous.

Micorscopic features:

GIST: Presence of spindle or epithelial cells with variable architecture, nuclear atypia and myxoid or hyalinized stroma. Necrosis and hemorrhage present in some cases.

Intra-abdominal fibromatosis: Composed of broad, sweeping fascicles of monotonous spindle cells. Bland nuclear features, and finely collagenous stroma. Necrosis, hemorrhage, and myxoid denegeration are not seen.

HIFU in Uterine Fibroids

Uterine fibroids or myomas are the most common tumours to affect women, and are present in up to 40% of women in the reproductive age group. Not all of these women are symptomatic, and they usually do not require any treatment for these fibroids. Occasionally, the fibroids can cause pain, heavy menstrual as well as inter-menstrual bleeding, and pressure effects such as frequency of urination due to the size of the fibroid. In a small number of cases, fibroids can be a cause of infertility.

Fibroids are traditionally known to grow very slowly throughout the reproductive life of a woman, and they exhibit a growth spurt during pregnancy. After menopause, a fibroid typically begins regressing in size, and at this stage, fibroids rarely need to be treated.

Attempts at symptomatic relief through medications have largely been unsuccessful, leaving the patient suffering from fibroids no option other than surgery.

The mainstay of treatment of symptomatic fibroids has been surgery, which could be either myomectomy (removal of the fibroid), or hysterectomy (removal of the uterus). Of these, only hysterectomy ensures that the patient will never suffer from fibroids again, but is a rather radical option for a benign tumour that only requires symptomatic relief. Also, a hysterectomy is followed by a lengthy recovery period before the patient returns to normal activities. Both hysterectomy as well as myomectomy can also be done laparoscopically (key-hole surgery), dramatically reducing the post- operative morbidity. However, even these are invasive techniques, and the risks and possible complications of surgery and anesthesia remain a constant threat.

The search for non-invasive techniques to provide the patient with relief from this otherwise non- threatening illness led to other minimally invasive options like Uterine Artery Embolisation, and Radio- Frequency Ablation which however had limited efficacy, and considerable adverse effects like excruciating post-treatment pain.

MRI guided HIFU or Magnetic Resonance Imaging- guided High Intensity Focused Ultrasound is an innovative mode for genuinely non-invasive treatment of fibroids. Under MRI guidance, sound waves are passed into the body and focused into the fibroid to heat and coagulate the tissues.

As fibroids are almost always benign, with a neglible percentage showing the presence of a sarcoma (malignancy),fibroids only require treatment for the alleviation of symptoms due to the fibroid.

This is a day-care surgery, where the patient reports to the clinic for the procedure, undergoes the procedure and is able to walk out and go home after the procedure. The patient is able to go back to her regular routine within the next 24 hours, and the symptomatic relief obtained with this procedure is comparable to that following a myomectomy in the long term

In this procedure, the MRI acquires high resolution 3-D images of the fibroid and surrounding structures. These images are used for accurate planning and mapping of the treatment. During treatment, the HIFU transducer focuses the ultrasound beam into the fibroid as per the planned areas (cells) and heats the tissue up to 65 degree Celsius, coagulating it. This is called sonication.

MRI guided HIFU ensures patient safety by having a number of safety mechanisms built into the system. All of these ensure that apart from the tissue being targeted, no other organ or tissue is affected by the treatment.

In a nutshell, MRI guided HIFU satisfies the need for a non-invasive procedure that is a safe, gentle, and convenient way to provide long-lasting relief from the symptoms caused by uterine fibroids