Bone metastases of medulloblastoma in childhood; correlation with flow cytometric DNA analysis

Thirty children with medulloblastoma who were treated between 1980 and 1986 are presented. Flow cytometric DNA analysis using formalin-fixed and paraffin-embedded tissues showed that 15 were DNA aneuploid, 13 diploid and 2 tetraploid. After homogeneous treatment with a combination of radical resection and radiation therapy, patients with DNA aneuploid medulloblastoma showed significantly better outcome (p = 0.003). Among these 30 patients, 6 (20%) had bone metastases of medulloblastoma during a minimum of 2-year follow-up period. DNA ploidy of these patients was diploid in 5 and aneuploid in 1. Incidence of bone metastases appears to correlate with DNA ploidy (p = 0.046). At the time of discovery of bone metastases, 4 had no demonstrable recurrence in the central nervous system (CNS). Radionuclide bone scan was more sensitive in disclosing these lesions, while only one patient had positive results of bone marrow aspirates/biopsy. Three patients were treated with chemotherapy, two had a combination of regional irradiation and chemotherapy and one refused treatment. All treated bone metastases in 5 patients responded clinically and radiographically, but only one patient is alive 66 months after therapy. Four patients died due to either CNS recurrence of septic complication of chemotherapy. Early detection of bone metastases by use of frequent bone scans is important. Patients with diploid medulloblastoma should be treated with adjuvant chemotherapy in order to prevent recurrences and metastases.