Infantile rhabdomyofibrosarcoma: a distinct variant or a missing link between fibrosarcoma and rhabdomyosarcoma?

Infantile rhabdomyofibrosarcoma (IRMFS) is a rare soft tissue tumour affecting infants and young children. It occupies an intermediate position between infantile fibrosarcoma and spindle cell rhabdomyosarcoma in its clinical presentation, behaviour, morphology, immunohistochemical and ultrastructural features. This case is reported here to reiterate its occurrence as tumour with distinct morphological immunohistochemical and clinical behavioral patterns.