Introduction

Congenital infantile fibrosarcoma is a rare neoplasm. Elaborate…..After obtaining IRB approval (#YYYYYYY), we reviewed a recent case.

Case Report

We report a case of a newborn term infant with a right buttock/paraspinal mass (Figure 1). Pregnancy and delivery (?SVD) were uneventful? The mother was a X year old PxGx with no underlying medical problems. Birth weight was X kg. No mass was initially appreciated, but within the first few days of life a right posterior buttock and paraspinal swelling was noted which mother felt was enlarging. Elaborate….

The lesion was initially radiographically interpreted as a hemangioma. However, review of the images with senior radiologists led to the report that although the lesion might be a hemangioma, a soft tissue neoplasm was a possibility. Because of these concerns, the baby was electively taken to the operating suite on the X day of life. An oblique incision over the mass was made, and a firm, well vascularized lesion was identified, measuring 6.0cm by 2.2 cm. The peripheral margins were well circumscribed, but the lesion was intimately attached to the sacrum at the sacroiliac region, and was shaved off the bone at that point. The baby recovered uneventfully. Pathologic and cytologic examination of the specimen confirmed the diagnosis of congential infantile fibrosarcoma, with involvement of the margin. [Note: can we get a gross path and FISH picture from pathology?] Cytological examination via fluorescenct in situ hybridization (FISH) analysis demonstrated abnormal female karyotype with trisomy of chromosomes 11 and 20 and rearrangement of chromosomes 3q, 12p, 12q, and 15q. The rearrangements were consistent with a variant of the typical t(12;15) of congenital fibrosarcoma. FISH analysis (CG-10-2495) confirmed ETV6 gene (12p13) rearrangement.

Discussion

A recent analysis of the SEER database from 1973 to 2006 (23 years) found an incidence of soft tissue sarcoma (STS) in the first year of life of 16 per million, accounting for 7.3% of malignancies reported in the first year of life. One-fifth were metastatic at the time of diagnosis. There were 74 fibrosarcomas, accounting for 24.5% of all STS. Rhabdomyosarcoma was the most common tumor type (32.8%), followed by fibrosarcoma.

The 5-year survival of STS in children less than 1year of age was significantly lower than in older children (62+/-3.0% versus 71+/-0.9%, P=0.0002). However, infantile fibrosarcoma and infantile haemangiopericytoma had better outcomesthan other types of STS.

A recent review of 56 children under age 2 years with infantile fibrosarcoma treated in Europe between 1979 and 2005 (26 year interval) found that the extremities were the primary site in 66% of patients.Historically, the amputation rate often exceeded 50%. Preoperative chemotherapy in selected cases has lowered that rate. More than half had a median tumor diameter greater than 5 cm. Local control was obtained in 84% of patients.The five year overall survival rate was 89%. These authors concluded that complete resection was rarely feasible at diagnosis. However, they recommended conservative surgery rand avoidance of potentially debilitating aggressive resection. A 75% response rate was obtained with vincristine-dactinomycin.

Genetic abnormalities have been reported in association with infantile fibrosarcoma, specifically abnormalities of chromosomes 11,17, and 20.

These tumors present difficulties with both clinic and histologic diagnosis. The radiographic appearance often mimics that of hemangioma , and the microscopic picture may be confused with fibromatosis or with malignant mesenchymal neoplasms.

References