Myeloid/Lymphoid Neoplasm with Eosinophilia & FGFR1 Rearrangement

Lessons From the Friday Unknows

Histologic sections of the lymph node show extensive replacement by neoplasm with a diffuse pattern.

The neoplasm has two components. One component representing 90–95% is composed of immature lymphoid cells with blastic chromatin consistent with lymphoblasts. Mitotic figures…