8814/3 Infantile fibrosarcoma


Synonyms

Congenital fibrosarcoma

Definitions

Connective, subcutaneous and other soft tissues
ICD-O-3 topography code: C49
ICD10: C49
           

Infantile fibrosarcoma (IFS) is histologically identical to classic fibrosarcoma of adults, but the prognosis is generally much more favourable.
IFS most commonly affects the superficial and deep soft tissues of extremities (especially distally), trunk, and the head and neck region. The tumours are poorly circumscribed, lobulated masses with irregular and infiltrative margins which entrap adipose tissue, skeletal muscle and other structures. They grow rapidly and may exceed 30cm in diameter. Histologically, IFS is characterized by intersecting fascicles of primitive ovoid and spindle-shaped cells which show a herringbone growth pattern or form interlacing cords, sinuous band or sheets. Most tumours contain scattered chronic inflammatory cells. Areas of necrosis and haemorrhage are common. The majority of cases carries a(12;15)(p13;q26) translocation 1
 
Fletcher CDM, Unni KK, Mertens F (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of Soft Tissue and Bone.
3rd Edition
IARC Press: Lyon 2002



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IFS almost exclusively affects children <2 years of age and shows a slight predilection for males. 36%-80% of cases are congenital. The tumours rarely metastasize; the recurrence rate is 5-50% and mortality ranges from 4-25%
2
 
Fletcher CDM, Unni KK, Mertens F (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of Soft Tissue and Bone.
3rd Edition
IARC Press: Lyon 2002



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