Infantile Fibrosarcoma

  • Etiology: Spindle cell tumor
  • Imaging:
    — Heterogeneous soft tissue mass with hemorrhagic or necrotic or fibrous or cystic components
    — May have higher flow vessels mimicking infantile hemangioma
  • Imaging MRI: Well demarcated
    — T1WI: Isointense to muscle
    — T1WI post contrast: Heterogenous enhancement
    — T2WI: Heterogenously hyperintense to muscle
  • DDX:
  • Complications:
    — Can have local recurrence so need to do wide excision
    — Low rate of metastases (8%) and high long term survival unlike fibrosarcoma in adults
  • Treatment: Surgical
  • Clinical:
    — Rapidly growing
    — Most common soft tissue sarcoma in less than 1 year old
    — Mostly in neonates and usually in less than 1 year old
    — Greater than 70% in extremities with 60% being in lower extremities

Radiology Cases of Infantile Fibrosarcoma

US and CT of infantile fibrosarcoma
Sagittal US of the mass (above) revealed increased vascularity peripherally and central ulceration. Axial and sagittal CT with contrast of the chest (below) shows a mass arising near the right scapula of heterogenous density with variable enhancement.

Clinical Cases of Infantile Fibrosarcoma

Clinical image of infantile fibrosarcoma
Clinical image shows a large mass in the upper right back with overlying skin necrosis.
Clinical image of infantile fibrosarcoma
Clinical image shows a large firm mass near the right scapula with overlying skin necrosis.

Surgery Cases of Infantile Fibrosarcoma

Surgical image of infantile fibrosarcoma
Surgical image shows an en bloc excision of the mass along with the overlying skin.

Gross Pathology Cases of Infantile Fibrosarcoma

Pathology image of infantile fibrosarcoma
Gross pathological image after en bloc resection shows a large solid mass.

Histopathology Cases of Infantile Fibrosarcoma

Histopathology slide of infantile fibrosarcoma
Histopathological image H&E stained section shows a densely cellular neoplasm characterized by interlacing fascicles of relatively uniform, spindle-shaped cells with scattered mitoses.
Histopathology slide of infantile fibrosarcoma
Histopathological image H&E stained slide shows a dense proliferation of spindle-shaped cells with plump nuclei. The cells are often arranged in short bundles or fascicles.