Mixed Phenotype Acute Leukemia, Rare Types

**Semantic type:** Neoplastic Process

**Definition:** A very rare mixed phenotype acute leukemia in which the blasts express combinations of B, T, myeloid, and megakaryocytic lineage markers but are negative for KMT2A rearrangement and t(9;22)(q34;q11.2) translocation. The prognosis is usually unfavorable.

**Synonyms:** - Mixed Phenotype Acute Leukemia, NOS, Rare Subtypes - Mixed Phenotype Acute Leukemia, NOS, Rare Subtypes - Mixed Phenotype Acute Leukemia, Not Otherwise Specified, Rare Subtypes - Mixed Phenotype Acute Leukemia, Rare Subtypes