P01.055 Multiple extracranial metastases in a patient with oligodendroglioma - a case report

Abstract Background Extracranial metastases (EM) in brain tumors are extremely rare. Oligodendroglioma is the least common brain tumor type to metastasize. Reported extracranial sites are bone, bone marrow, lymph nodes, liver, lung and scalp. Risk factors are prior neurosurgical resection and a prolonged survival of low grade glioma patients. No standard treatment exists, but temozolomide is the preferred treatment option. Material and Methods This work is a single case observation of a patient with oligodendroglioma and multiple EM. Histology was confirmed by an independent reference center. Results In 1997 a now 49-year-old male patient was diagnosed with oligoastrocytoma WHO II sinistral frontoparietal. In 2004 and 2009 local recurrence was detected. He received total resection and adjuvant chemotherapy (PCV). Histology showed an oligodendroglioma with anaplastic parts and a partial loss of 1p19q. 2012 again local recurrence was detected in MRI and the patient underwent gamma knife treatment. In August 2016 a calvaria lesion occurred, the histology revealed bone metastasis of oligodendroglioma. A PET-CT ten months later showed multiple thoracic and femoral bone metastases, while the lungs were tumor free. No specific treatment was obtained.In November 2017, the patient was admitted due to lymphadenopathia in both cervical regions. Biopsy showed infiltration by a population of cells consistent with metastatic glioma, showing positivity for Olig2, GFAP, S100 and SOX10 and 1p/19q co-deletion. KI-67 was 40%. The diagnosis was confirmed by an independent reference center. Currently the patient is receiving a 5/28 days temozolomide monotherapy regimen with 150mg/m2. A severe isolated normocytic and normochromic anaemia occurred propable on the basis of bone marrow involvement. Conclusion EM of oligodendrogliomas are rare and infrequently reported. According to literature, most common sites include bone and bone marrow, as well as lymph-nodes and pulmonary metastasis. In our case the intracerebral lesion has been stable after the last treatment with gamma knife 2012. EM occurred 19 years after presentation of the primary tumor, this is above the range (months up to ten years) described in literature.The route of dissemination remains obscure. In some cases of neurosurgical excision material has been spread by seeding, which - due to the location in the skull - is unlikely in this case. The seeding into remote parts of the skull and lymph nodes, suggest a haema