CNS Metastases from Bone and Soft Tissue Sarcomas in Children, Adolescents, and Young Adults: Are They Really So Rare?

Abstract

Purpose. To check whether primary involvement of brain/spinal cord by bone/soft tissue sarcomas' metastases in children is as rare as described and to present various morphological forms of bone/soft tissue sarcomas' CNS metastases. Methods. Patients with first diagnosis in 1999–2014 treated at single center were included with whole course of disease evaluation. Brain/spinal canal magnetic resonance imaging (MRI)/computed tomography were performed in cases suspicious for CNS metastases. Extension from skull/vertebral column metastases was excluded. Results. 550 patients were included. MRI revealed CNS metastases in 19 patients (incidence 3.45%), 14 boys, aged 5–22 years. There were 12/250 osteosarcoma cases, 2/200 Ewing's sarcoma, 1/50 chondrosarcoma, 3/49 rhabdomyosarcoma (RMS), and 1/1 malignant mesenchymoma. There were 10 single metastases and 7 cases of multiple ones; in 2 RMS cases only leptomeningeal spread in brain and spinal cord was found. Calcified metastases were found in 3 patients and hemorrhagic in 4. In one RMS patient there were numerous solid, cystic, hemorrhagic lesions and leptomeningeal spread. Conclusions. CNS metastases are rare and late in children with bone/soft tissue sarcomas, although in our material more frequent (3.45%) than in other reports (0.7%). Hematogenous spread to brain and hemorrhagic and calcified lesions dominated in osteosarcoma. Ewing sarcoma tended to metastasize to skull bones. Soft tissue sarcomas presented various morphological forms.

Rare Case of Sellar and Suprasellar Metastasis from Ewing’s Sarcoma of Tibia

“…In the majority of cases, CNS metastasis is the result of direct extension of bony metastasis in proximity to the brain tissue, while hematogenous brain metastases occur in less than 1.8% of the cases. [4715] Up to 80%–90% have subclinical metastasis at the time of presentation; however, the upfront metastatic disease is found in <25% of patients at the time of diagnosis. [1016]…”

“…Central nervous system (CNS) involvement in case of bone or soft-tissue sarcomas is rare. [34567] There is heterogeneity in reported rates of CNS metastases in Ewing's sarcoma. Weins and Hattab[3] reported CNS metastases in 2% of cases of Ewing's sarcomas/primitive neuroectodermal tumors (PNET).…”

“…Bekiesinska-Figatowska et al . [4] reported brain metastasis in 1% of cases of Ewing's sarcoma. Porto et al .…”

Commentary

“…[5] Spread of ES to the central nervous system, is very rare, with only 1%–2% of all metastatic presentations extending to the brain or spine. [67] Although the modality of extension can be diverse for metastatic tumors of the bone, ES is known to primarily metastasize to the skull bones although hematogenous spread is possible. [2678] Following spread to the skull bones, and more specifically the skull base, direct extension can cause mass effect on local structures, leading to the bulk of primary neurologic presentations of metastatic ES.…”

“…However, in a patient with a recent or remote oncologic history and evidence of CSS, expedited neuroimaging (preferably magnetic resonance imaging [MRI]) with and without contrast should be obtained as the risk of neoplastic spread to the cavernous sinus or surrounding bony structures is high. [78] Obtaining an MRI with views of the venous architecture may also be relevant as venous sinus thrombosis (in both oncologic and nononcologic states) is on the differential and must be ruled out.…”