Congenital/infantile fibrosarcoma in a 3-week-old boy.

[FIGURE 1 OMITTED]

A 21-day-old boy was brought to the emergency department with bleeding from a left neck mass. He had been born at full term with a small subcutaneous left neck mass that was suspected of being a hemangioma. The lesion rapidly increased in size and eroded through the skin. A small amount of bleeding began on the morning of presentation.

Examination revealed a 5 x 5-cm mass in the left posterior neck with an area of central ulceration. Serology revealed a platelet count of 469,000/[mm.sup.3] and a hemoglobin level of 11.6 g/dl. The activated partial thromboplastin time (aPTT), prothrombin time (PT), and international normalized ratio (INR) were normal. Computed tomography (CT) of the neck with intravenous contrast demonstrated a heterogeneously enhancing soft-tissue mass in the subcutis of the left neck (figure 1).

The patient was admitted and treated for suspected hemangioma with intravenous dexamethasone, but after 48 hours, the size of the mass had not changed. The patient was then taken to the operating room for excision of the mass with an overlying ellipse of skin (figure 2). Histologically, the lesion was characterized by solidly packed sheets of spindle cells arranged in fascicles that imparted the appearance of a herringbone pattern in some areas (figure 3). Cytogenetic analysis of the neoplasm identified a rearrangement involving chromosome 12p13 that was consistent with a diagnosis of congenital/infantile fibrosarcoma (CIF). The patient recovered well from surgery, and follow-up imaging for distant metastases detected no evidence of tumor.

[FIGURE 2 OMITTED]

CIF is a rare malignant neoplasm that generally affects children younger than 5 years of age. It typically presents as a firm, painless soft-tissue mass, and it exhibits a steady, sometimes rapid, growth rate. Approximately 13% of these tumors occur in the head and neck.

Magnetic resonance imaging of CIF will demonstrate a heterogeneously enhancing mass with solid and cystic components. Invasion of surrounding structures may be seen, and flow voids will be present secondary to dilated vessels with rapidly flowing blood. CIF can be differentiated from hemangioma in that the latter is a well-defined mass with homogeneous rather than heterogeneous enhancement.

Histologic analysis of CIF will reveal spindle cells in bundles or fascicles within dense stromal tissue and scattered inflammatory cells. Large cavernous vascular channels and mitotic activity are common. The tumors often exhibit areas of necrosis and invasion of surrounding soft tissue. Cytogenetic studies have demonstrated translocations between chromosomes 12p13 and 15q25 that lead to the gene fusion product ETV6-NTRK3 with an intra-cellular tyrosine kinase domain.

The primary treatment of CIF is wide local excision. Residual disease increases the risk of recurrence, and the presence of tumor at resection margins has been successfully managed with observation, chemotherapy, and radiation therapy. Neoadjuvant chemotherapy has been used to decrease tumor size prior to limb-sparing resection in some patients. Unresectable lesions have been treated with primary chemotherapy with good response.

[FIGURE 3 OMITTED]

Despite a lack of consensus on postoperative therapy, the prognosis for patients with CIF is generally good, as 5-year survival rates range from 84 to 90%. Local recurrence rates range from 17 to 43%; recurrence usually occurs within 12 months of the initial surgical resection. Repeat resection may be performed for local recurrence. Distant metastases occur in 5 to 10% of patients; they may be treated with resection or chemotherapy.

Suggested reading

Boon LM, Fishman SJ, Lund DP, Mulliken JB. Congenital fibrosarcoma masquerading as congenital hemangioma: Report of two cases. J Pediatr Surg 1995;30(9):1378-81.

Chung EB, Enzinger FM. Infantile fibrosarcoma. Cancer 1976;38(2): 729-39.

Loh ML, Ahn P, Perez-Atayde AR, et al. Treatment of infantile fibrosarcoma with chemotherapy and surgery: Results from the Dana-Farber Cancer Institute and Children's Hospital, Boston. J Pediatr Hematol Oncol 2002;24(9):722-6.

Soule EH, Pritchard DJ. Fibrosarcoma in infants and children: A review of 110 cases. Cancer 1977;40(4):1711-21.

Swain RE, Sessions DG, Ogura JH. Fibrosarcoma of the head and neck in children. Laryngoscope 1976;86(1):113-16.

Dary J. Costa, MD; Ron B. Mitchell, MD; David S. Brink, MD

From the Department of Otolaryngology--Head and Neck Surgery (Dr. Costa and Dr. Mitchell) and the Department of Pathology and the Department of Pediatrics (Dr. Brink), St. Louis University School of Medicine.