ICD-10-CM > C00-D49 > C81-C96 > C96 > C96.2 C96.2 Malignant mast cell neoplasm Non-Billable/Non-Specific Type 1 Excludes indolent mastocytosis (D47.02)mast cell leukemia (C94.30)mastocytosis (congenital) (cutaneous) (Q82.2) Codes C96.20Malignant mast cell neoplasm, unspecifiedC96.21Aggressive systemic mastocytosisC96.22Mast cell sarcomaC96.29Other malignant mast cell neoplasm