oral medicine & Pathology

Desmoid Fibromatosis : imaging , clinical findings , pathology , treatment , epidemiology

Desmoid Fibromatosis    

 

Epidemiology

  •  Desmoid fibromatosis is arbitrarily divided into two types: anterior abdominal wall and extra- abdominal wall.
  • The extra-abdominal variety, which is more common, is also known as musculoaponeurotic or aggressive fibromatosis.
  • The histologic appearances of these varieties are the same.
  • Approximately 1 0 to 30% of all extra-abdominal desmoids are found in the head and neck.
  •  Desmoid fibromatosis affects a wide age group ranging from infants to the eighth decade.
  • Most patients, however, are in the third and fourth decades.
  • There is no sex predilection for the extra-abdominal variety although there is a female preponderance in the abdominal type.

Clinical Findings

  • The lesion is firm to hard and is characteristically slow growing.
  • Most lesions are non-tender and painless.
  • They may be noted ro develop in previously irradiated fields or surgical scars.
  • Some lesions are multicentric.
  • Lesions resemble scar and may be impossible to distinguish from proliferating scar tissue both clinically and pathologically. 

Pathology

  •  The lesions are variable in size and may grow beyond 20 cm.
  • They develop within muscles, aponeurosis, or fascia and typically infiltrate the muscles along the long axis.
  • Microscopically, the muscles and aponeurosis are invaded by mature, uniform, spindle-shaped cells.
  • The infiltrative process separates the muscle bundles and these muscles eventually show atrophy.
  • In some patients these lesions turn sarcomatous.

Treatment

  • Lesions of head and neck desmoid fibromatosis appear more aggressive than lesions elsewhere.
  • They should be treated by wide surgical resections. Because of the infiltrative behavior, surgical clear margins are difficult to achieve.
  • Hence, recurrences are common (20-77%), and most lesions recur within the first 2 years.
  • Patients may die from aggressive local disease, and some patients may also have distant metastasis.
  • Chemotherapy may also be successful in some patients using nonsteroidal anti-inflammatory agents, tamoxifen, and colchicine.

Imaging Findings

CT

  • The CT findings of desmoid fibromatosis are nonspecific.
  • These tumors show variable enhancement and cannot be distinguished from malignant infiltrative lesions

MR

  • The MR findings are also nonspecific.
  • Lesions show intermediate signal intensity on T I weighted images and high signal intensity on T2-weighted images.
  • They enhance strongly after the injection of contrast

Imaging Pearls

              CT and MR imaging findings cannot distinguish desmoid fibromatosis from other malignant lesions. 

  • However, because of me slow growing process, bones rend to be remodeled rather than infiltrated .

              Desmoid fibromatosis may be multicenrric.

  • Hence, separate masses in the head and neck may point toward this diagnostic possibility.

 

 Desmoid Fibromatosis

Desmoid Fibromatosis

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