Congenital-infantile fibrosarcoma presenting as a hemangioma: a case report.

Introduction: Congenital-infantile fibrosarcoma (CIFS) is a rare pediatric soft tissue tumor that on initial clinical presentation can mimic an infantile hemangioma. Management of these conditions differs drastically, and delay in diagnosis and treatment may affect prognosis.

Methods: A 6-month-old male infant originally presented to dermatology for evaluation of a suspected right buttock hemangioma, present at birth as a small red mass just lateral to the gluteal cleft. The lesion rapidly grew over 2 weeks to a size of 4×4.5×4.5 cm, with violaceous color change and central ulceration. The patient received a course of cephalexin; however, the mass became painful with several episodes of bleeding and did not show clinical improvement. Magnetic resonance imaging and ultrasound supported the diagnosis of atypical hemangioma.

Results: Plastic Surgery was consulted for excision due to recurrent bleeding. An excisional biopsy was undertaken and pathologic finding showed CIFS. The case was discussed with Hematology/Oncology and Pediatric Surgery, and the patient underwent re-excision and obtained clear margins. Initial metastatic workup was negative; however, patient had evidence of recurrent disease as well as pulmonary metastasis on his most recent surveillance imaging. He underwent re-excision of the gluteal mass and is currently receiving adjuvant chemotherapy.

Conclusions: This case demonstrates a rare malignancy initially misdiagnosed as a hemangioma. Consideration of CIFS is crucial in cases of complicated hemangiomas not responding to standard treatment. Treatment calls for excision with wide margins and/or adjuvant chemotherapy if excision is not possible. Classic pathologic findings, immunohistochemistry, and/or reverse transcription-polymerase chain reaction can confirm the diagnosis. A correct and rapid diagnosis of CIFS is critical to optimizing treatment and subsequent prognosis.