Peripheral blood demonstrating macrocytosis without thrombocytopenia. Atypical, large platelets can be appreciated (arrow).
Bone marrow aspirate smear
The marrow aspirate smear is cellular with trilineage hematopoiesis.
Many atypical megakaryocytes are seen characterized by small size, hypolobated or non-lobated nuclei, and often plasmacytoid appearance with eccentric nuclei. Erythropoiesis and granulopoiesis are relatively unremarkable. Blasts are not increased.
Bone core biopsy
Core biopsy also demonstrates atypical, hypolobated megakaryocytes (arrow).
Conventional karyotype analysis demonstrates deletion of the long arm of chromosome 5 (arrow).