Reasons for missed SM diagnoses. (A) Use of diagnostic BM in 41 SM cases that were missed by 1 July 2021. (B) Reasons why BM was not offered. (C) BMB errors in cases where BMB was performed. Note: 6 of 47 patients diagnosed with SM after 1 July 2021 did not have their SM diagnoses missed by 1 July 2021 because of being referred directly to a center of excellence. In addition, 14 of 47 patients had IHC errors after 1 July 2021 that required expert hematopathologist evaluation.