Temporary response of localized intracranial mast cell sarcoma to combination chemotherapy

Cerebral involvement of systemic mastocytosis and intracranial sarcoma of m yelogenic origin are well known entities. An 8-year-old girl with an isolat ed cerebral mast cell tumor is presented. Specific histopathologic stains w ere used to confirm the diagnosis detecting immunophenotype and proliferati ve activity. Treatment with irradiation, intrathecal cytarabine. and interf eron-alpha 2b did not induce regression whereas polychemotherapy did. Syste mic combination chemotherapy led to marked transient tumor regression in th is proliferating mast cell sarcoma in an unusual intracranial location.