Primary intracerebral mesenchymal chondrosarcoma with rhabdomyosarcomatous differentiation: case report and literature review

Intracranial chondrosarcoma (Ch-S) is a slow-growing, locally recurrent, malignant cartilaginous tumour of the skull base. Intracranial mesenchymal chondrosarcoma (MsCh-S) is a rarer, more malignant variant associated with the supratentorial meninges. Only seven cases of Ch-S, and six of MsCh-S, that were primarily intraparenchymal in origin have been reported. Moreover, no case of intracranial Ch-S or MsCh-S has been reported in which rhabdomyosarcomatous differentiation was prominent. A 17-year-old Asian girl presented with a 4-week history of occipital headache, vomiting and paraesthesia in the left hand. She was drowsy with a left hemiparesis and had a dilated right pupil with bilateral papilloedema. CT demonstrated a large, partly calcified, contrast-enhancing mass in the right temporo-parietal region with oedema and midline shift. Through a large craniotomy, a tense brain was encountered with no apparent cortical abnormality. Despite a radical tumour excision, with excellent initial clinical recovery, a local recurrence rapidly occurred within weeks prior to the administration of any radiotherapy. Initial histopathological examination revealed a primary MsCh-S with osseous and rhabdomyosarcomatous differentiation, with an indistinct margin. After a second radical excision, a second recurrence rapidly occurred; however, this proved excessively vascular and inoperable. Radiotherapy was declined and death followed within 3 weeks. This is the seventh case of primary intracerebral MsCh-S to be reported and the first to demonstrate rhabdomyosarcomatous differentiation. It was characterized clinically by rapid, local recurrence with increased vascularity.