Congenital infantile fibrosarcoma of the foot

Infantile fibrosarcoma (IFS) is a malignant soft tissue tumour and rarely presents in the newborn period. Congenital IFS poses a particular diagnostic challenge, as they may clinically and radiologically mimic vascular anomalies, such as haemangiomata.We present a case of a baby boy who, at birth, was noted to have a smooth mass of approximately 4 cm×4 cm on the sole of his right foot. Newborn examination was otherwise unremarkable. Atypical haemangioma was considered the most likely diagnosis.However, as the mass had grown very rapidly, an urgent MRI and biopsy were performed, confirming the diagnosis of fibrosarcoma. Following a course of chemotherapy to reduce the size of the tumour, he underwent ankle disarticulation to remove the tumour completely. He is currently doing very well, with no signs of local recurrence.