#00063796

57 year old female with fever, generalized weakness and pancytopenia was diagnosed with Acute Myeloid Leukemia with t (8;21) and KIT Exon 17 (Asp-816-His) mutation. Received 4 cycles of chemotherapy (Azacytidine + venetoclax) and marrow was sent for MRD assessment. Bone marrow aspiration revealed less than 5% blasts with mast cell hyperplasia, composed of aggregates of spindled atypical mast cells. Flowcytometry showed <0.1% MRD with atypical mast cells expressing CD117, CD25 and CD2. After 5 cycles of chemotherapy, Dasatinib was started.

Mastocytosis with AML may be difficult to establish because the associated malignancy may mask the cytological features of mastocytosis and mast cells have tendency to localize within marrow particles. A reduction in blast cell percentage at the time of a post-induction marrow evaluation helps in unmasking mastocytosis.