대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Fibromatosis (Mediastinal Desmoid Tumor)

Radiologic Findings

A 50-year-old man presented with left arm tingling sensation and palpable mass in left lower cervical neck for several months. Chest radiograph shows an large mediastinal mass (about 7.6 cm) in the left upper upper hemithorax. MR scans show well defined dumbbell shaped mass at the left highest mediastinum with extrathoracic extension to the lower cervical neck. This mass shows relatively homogeneous iso signal or slight low signal intensity on T1WI and high signal intensity on T2WI with strong delayed enhancement. After excision of the mass, recurred lesion was noted on the follow up chest CT scans at 23 months with gradual increase of the size on serial follow up CT scans.

Brief Review

Desmoid tumor

Desmoid tumors are characterized by proliferation of fibroblastic cells that arise from the fascia or aponeurosis of muscle

Clinical characteristics

Group of disorders called fibromatoses

Fibroblastic proliferation, without evidence of inflammation or definite neoplasia

Abdominal desmoids
Extraabdominal desmoids

    = Musculoaponeurotic fibromatoses

Desmoids may occur at any age

Peak incidence in the 3rd decade

Extraabdominal lesions do occur in young children

Causative factors

Some systemic (perhaps genetic) defect in connective tissue formation: Gardner syndrome
Previous trauma at the site of the lesion
Multiple pregnancies

Firm

Poorly or well circumscribed

Deep-seated masses that grow slowly

Benign appearance at microscopy, the tumors frequently behave in a locally aggressive manner

Reported recurrence is 25%-65%

Radiation therapy

Imaging finding

Amounts of fibroblast proliferation, fibrosis, collagen content, and vascularity

US

Masses of low, medium, on high echogenicity with smooth, sharply defined margins
The lateral bonders may appear ill defined on irregular

CT

Ill defined or well circumscribed
Variable attenuation, relative to muscle
Higher attenuation than that of adjacent muscles
May or may not appear enhanced

MRI

Low signal intensity relative to muscle on T1WI
Variable signal intensity T2WI

The diagnosis of desmoid tumor should be strongly considered in patients with

Abdominal mass

History of previous abdominal surgery

Gardner syndrome

Extraabdominal desmoids are less common

D/D  soft-tissue mass

Chest wall desmoid

Direct trauma to the chest, previous mastectomy, and excision of a neurofibroma
In the 4th decade of life, predominantly in women
External surface of the chest wall (ribs) on scapula or arise from paravertebral tissues
Tumors may extend into the thorax and may involve the brachial plexus and axillary vessels

The surgical results for desmoid tumors in this location

Differential diagnosis of desmoid tumors

Malignant:  Fibrosarcoma, rhabdomyosarcoma, synovial sarcoma,      liposarcoma, synovial sarcoma, liposarcoma, fibrous histiocytoma, lymphoma, and metastases

Benign: Nerofibroma, neuroma, and leiomyomas

Hematomas (acute): Rectus sheath, chest wall, mesentery, retroperitoneum, and space of Retzius

References

1. Casillas J., Salis GJ, Grere JL, et al. Imaging of intra- and extraabdominal desmoid tumors. Radiographics 1991:11;959-968

2. Tateish U, Galdish GW, Kusumoto M, et al. Chest wall tumor; radiologic findings and pathologic correlation, part 2: malignant tumors. Radiographics 2003:23;1491-1508

3. Kingston CA, Owens CM, Jeanes A. Imaging of desmoid fibormatosis in pediatric patients. AJR 2002:178;191-199

Keywords

Mediastinum, Benign tumor,