myxofibrosarcoma

Myxofibrosarcoma is a malignant soft tissue tumor. It is classified as a type of a fibroblastic/myofibroblastic tumor.

Terminology

Previously known as a myxoid variant of malignant fibrous histiocytoma .

Epidemiology

Typically presents in older patients (6 decade) . There may be male predilection. Although rare in general, it is considered the most common soft tissue tumor to present in late adult life.

Clinical presentation

Patients often present with a painless enlarging soft tissue mass in the extremities.

Pathology

Location

Tends to favor the dermal and subcutaneous tissues than deeper soft tissues :

  • lower limbs (~77%)
  • trunk (~12%)
  • retroperitoneum/mediastinum (~8%)
  • head and neck (3-10%)
Histology

In contrast to most other histologic types of low-grade soft-tissue sarcoma, recurrent low-grade myxofibrosarcomas are often infiltrative; shows tapering, have tail-like margins with superficial spreading configuration and can even metastasize to various distant sites .

Radiographic features

MRI

Myxofibrosarcoma often shows abnormal signal infiltration along the fascial plane on MRI .

Signal characteristics
  • T1: the myxoid component is often of low signal
  • T2/STIR: the myxoid component is high signal
  • T1 C+ (Gd): the myxoid component tends not to enhance while the remaining soft tissue component enhances

Treatment and prognosis

Prognosis will somewhat depend on grade .