The presence of metastatic disease in patients newly diagnosed with medulloblastoma remains one of the most important prognostic factors that determines event-free survival. In the present study, anatomic distribution and the signal characteristics and enhancement patterns of subtle anterior third ventricular recess metastases were compared with those of the original tumor; medical records were reviewed for clinical presentation, surgical stage, treatment and long-term outcomes. All foci were clinically occult; 5 out of 6 had negative cerebrospinal fluid cytology, and in 4 out of 6, the only evidence of metastatic disease was documented suprasellar disease that resolved or significantly improved following irradiation and chemotherapy. Histologically, 3 of the 6 patients had tumors with large cell/anaplastic features, a significant increase compared to the expected incidence of 4-8.8%. Patients with tumors that show large cell/anaplastic features may be at higher risk for early metastatic involvement of this unusual site.
Copyright 2002 S. Karger AG, Basel