The patient originally presented to the ER with swelling and pain of the whole right lower limb. Ultrasound was negative for DVT but marked inguinal lymphadenopathy with femoral/external iliac vein compression was seen, as well as enlarged popliteal lymph nodes. A subsequent abdominal CT (not shown) showed marked periaortic and iliac lymphadenopathy. The patient admitted that some time ago he noted slow-onset progressive swelling of his right forefoot and MR examination of this area was performed (shown above).

A biopsy of the forefoot lesion and of one of the inguinal lymph nodes was performed, with intraoperative pathology reporting small blue round cells in both samples. Further histopathology reported alveolar rhabdomyosarcoma with lymph nodes metastasis.  

Rhabdomyosarcoma is the most common soft-tissue sarcoma in children, constituting more than half of the cases. The alveolar type accounts for approximately 20% of cases, is usually seen in adolescents and young adults and is often located in the extremities. It has the worse prognosis of all subtypes and lymph nodes involvement is an additional poor prognostic factor, which warrants an aggressive treatment approach.