Novel BMP2K::PDGFRA fusion in an unusual myeloid/lymphoid neoplasm with eosinophilia.

BACKGROUND

Myeloid and/or lymphoid neoplasms with eosinophilia PDGFRA gene fusions usually occur with FIP1L1 as the partner gene; however, novel partners have been described. These novel partners are sometimes responsive to tyrosine kinase inhibitor therapy.

PURPOSE: We describe here a patient with a PDGFRA fusion with a previously undescribed partner gene, BMP2K.

METHODS

RNA sequencing with the Archer Fusion Plex Pan Solid Tumor Panel (IDT) was used to detect fusions. DNA sequencing using a custom IDT panel was also performed.

RESULTS

An in-frame BMP2K::PDGFRA fusion was detected in a patient who had an ill-defined myeloid neoplasm with eosinophilia. The myeloid neoplasm had a prominent mast cell component and myeloid blast component in the lymph node, while the bone marrow showed hypercellularity, eosinophilia, and myelofibrosis. DNA NGS revealed a pathogenic TP53 mutation but was negative for mutations in other genes including KIT, JAK2, CALR, and MPL.

CONCLUSIONS

Given that PDGFRA fusions with novel fusion partners may respond to tyrosine kinase inhibitor therapy, partner agnostic testing methods should be considered either up front or as reflex testing in patients with myeloid and/or lymphoid neoplasms with blood, bone marrow, or tissue eosinophilia.