Bone metastases in medulloblastoma--single institution experience

Medulloblastoma has one of the highest rates of metastasis outside the central nervous system (CNS). Bone metastases are the most common lesions, although lymph node and visceral spread have also been reported.

To present patients with bone metastasis in medulloblastoma and discuss their radiologic appearances and treatment approach.

From 1993 to 2008, 82 patients diagnosed with medulloblastoma were treated at the Institute for Oncology and Radiology of Serbia. Three (3.6%) developed extraneural metastasis (ENM). In primary treatment, patients were treated with surgery, craniospinal radiotherapy with local boost to tumor bed, and adjuvant chemotherapy [lomustine (CCNU) and vincristine]. Of the three patients with ENM, all developed bone metastases at the time of relapse. Relapse occurred within 17 to 42 months of initial diagnosis. Patients received secondary chemotherapy and palliative radiotherapy to the affected bone in two cases.

Among these three patients, case 1 had initially a solitary lytic lesion. Case 2 had diffuse blastic lesions and also bone marrow involvement. Case 3 had multiple mixed lytic-sclerotic lesions but later developed lymph node metastasis and metastases to both breasts, as well. All patients were without concurrent CNS involvement at the time of ENM. Unfortunately, after initial partial response, the three patients died at 24, 13, and 18 months after detection of metastases, respectively.

With prolonged survival times in children with medulloblastoma, more emphasis should be placed on the possibility of systemic involvement. A greater understanding of the pathogenesis of the systemic metastases may be valuable in designing future, more aggressive multimodal therapy.