Isolated CNS involvement in Ewing sarcoma

Brain metastases of sarcoma: a rare phenomenon in rare tumours

The usual site for distant metastases of sarcoma is lungs, while brain metastasis (BM) occurs much less frequently and usually late in the disease progression. Despite the advancement in cancer treatment, the outcome for patients with brain metastasis is poor, and their lifespan is short. The frequency of BM in sarcoma seems to be affected by the location and histology of the primary tumour. Sarcoma subtypes with a high propensity for brain metastasis are ASPS, leiomyosarcoma and osteosarcoma. There are no clear guidelines for the treatment of sarcoma brain metastasis. However, therapeutic options include surgery, radiotherapy and chemotherapy, and are often combined. Targeted therapies are a promising treatment option for sarcoma but require investigation in patients with BM. The following review presents the data on sarcoma brain metastasis incidence, treatment and prognosis.

Intracranial Ewing sarcoma

The occurrence of primary extraosseous Ewing sarcoma (EES) of the central nervous system (CNS) has only rarely been reported in the literature. It is important to distinguish this entity from the more common central primitive neuroectodermal tumor (PNET) of brain, since the management of these tumors is different from that of EES. We present the clinical, radiologic, and pathologic features of two cases of EES occurring in the brain. The diagnosis was further confirmed by detection of a rearrangement of the FLI1 and/or EWS gene loci in tumors from both patients using fluorescent in situ hybridization (FISH). Although rare, the possibility of EES should be considered particularly when tumors that arise near the meningeal surface of the brain and have the pathologic appearance of a PNET. Demonstration of t(11;22)(q24;q12) by molecular analysis essentially confirms the diagnosis and enables the oncologist to choose appropriate therapy.