Complete Response of Myeloid Sarcoma with <b><i>FIP1L1-PDGFRA</i></b>-Associated Myeloproliferative Neoplasms to Imatinib Mesylate Monotherapy

Abstract

Myeloid sarcoma (MS) is a localized, extramedullary tumor of acute myeloid leukemia (AML) that typically presents either de novo or concomitantly with myeloproliferative neoplasms (MPN), AML and myelodysplastic syndrome. Patients who have MS must be treated with intensive chemotherapy, as are patients with AML, because MS usually progresses to a systemic manifestation and leads to dismal outcomes. FIP1L1-PDGFRA-associated MPN, a subtype of myeloid and lymphoid neoplasm, is characterized by eosinophilia and abnormalities in the PDGFRA, PDGFRB or FGFR1 gene. Fusion of the FIP1L1 and PDGFRA genes activates the tyrosine kinase. As a result, imatinib mesylate (IM) is widely used for the treatment of this disorder. The coexistence of FIP1L1-PDGFRA-associated MPN and MS is extremely rare. Patients with this condition fail to achieve durable remission and long-term survival without a combination of intensive chemotherapy and IM. Here, we report a case of MS and FIP1L1-PDGFRA-associated MPN that was successfully treated with IM monotherapy.

Complete and long‐lasting cytologic and molecular remission of FIP1L1‐PDGFRA‐positive acute eosinophil myeloid leukaemia, treated with low‐dose imatinib monotherapy

“…In the second case, after the partial resection of the sarcomatous mass, imatinib has been administered at the dosage of 400 mg/d, followed by 100 mg/d, resulting in a complete remission after sixth month, with a reported follow-up of 12 months. In both cases, a rapid clinical and molecular response was obtained, after three and 6 months since the beginning of treatment, respectively (9,10).…”

Refractory myeloid sarcoma with a FIP1L1-PDGFRA rearrangement detected by clinical high throughput somatic sequencing

“…The diagnosis of acute myeloid leukemia or myeloid sarcoma with a FIP1L1-PDGFRA rearrangement is extremely rare, with only a handful of case reports in the literature [ 11 – 13 ]. The largest case series of patients with AML and a FIP1L1-PDGFRA rearrangement consists of 5 patients, all of whom achieved complete molecular remission with imatinib [ 14 ].…”

del(4)(q12q12) FIP1L1/PDGFRA

“…The updated WHO classification distinguishes these myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1 as chronic eosinophilic leukemia (CEL) not otherwise specified (NOS); lymphocyte-variant hypereosinophilia and idiopathic hypereosinophilic syndrome (HES) (Gleich and Leiferman, 2009;Gotlib, 2014). Occasionally, the FIP1L1-PDGFRA fusion can be identified in patients with acute myeloid leukemia or B-cell or T-cell acute lymphoblastic leukemia or lymphoblastic lymphoma and sporadically in myeloid sarcoma (Metzgeroth et al, 2007;Tang et al, 2012).…”