Selected bone marrow histology and physical findings associated with genetic MDS predisposition syndromes. (A) Hematoxylin and eosin (left panel) or May-Grunwald Giemsa staining of abnormal bone marrow megakaryocytes present in GATA2 predisposition disorders. (B) May-Grunwald Giemsa staining of bone marrow aspirate from a patient with SCN demonstrating myeloid maturation arrest (marrow images courtesy of M. Fleming). (C) Patient features characteristic of diagnostic triad of TBDs, including lacy/reticular pigmentation on neck and trunk, oral leukoplakia, and dystrophic fingernails (images courtesy of S. Agarwal).