Rhabdomyosarcoma (RMS) is a common soft tissue sarcoma in childhood, however, it is very rare in the neonatal period (0.4-2% of cases). This case depicts a boy, who presented with RMS at two weeks of age, but officially diagnosed at the age of three months. MRI and scintigraphy determined a soft tissue tumor in the soleus muscle, while biopsy confirmed embryonal RMS with high mitotic activity (Ki67 (monoclonal antibodies) ~80%). CWS (Cooperative Weichteilsarkom Studiengruppe)-2012 with I2VA (ifosfamide, vincristine, actinomycin) chemotherapy regimen was administered per protocol. Surgical treatment was performed at age of six months and 18 days. The operation consisted of radical tumor resection and total triceps surae with partial fibula resection. Immediate reconstruction of triceps muscle was accomplished using a vascularized functional musculocutaneous vastus lateralis flap. Functional outcome was measured using the Lower Extremity Functional Scale (LEFS) and the Foot and Ankle Outcome Score (FAOS) with the results of 92.5% and 99% respectively.
Keywords: embryonal rhabdomyosarcoma; functional vastus transplantation; infant microsurgery.