Delayed incision tract medulloblastoma metastasis in an adult

with systemic metastases, Eberhart et al³ reported a 91% rate of bone involvement, 13% soft tissue/lymph node involvement, and a 4% (one case) rate of lung metastasis. Their reported median time to metastasis was 18.5 months, ranging up to 11 years after initial treatment.

With respect to surgical seeding of disease resulting in metastases, several studies implicate ventriculoperitoneal (VP) shunt placement as a risk factor for developing extraneural disease. 2 Only one case report was found describing a case of subcutaneous seeding of medulloblastoma. Galarza2 et al reports a 6-year-old male patient who was diagnosed with cerebellar medulloblastoma and treated with VP shunting, tumor resection, and craniospinal radiation. Four months later, he presented with new masses in the nuchal area and abdominal wall, both of which were resected and proven to be medulloblastoma metastases. The authors suggested a mechanism of direct implantation during surgery, as the location of disease would be atypical for hematogenous or lymphatic spread.