She has a special interest in Breast and Lung pathology and participates in both cervical and diagnostic cytology rotas. She collaborates in various research projects in both breast and lung and has published over 70 academic  papers in prestigious journals including Nature and The new England Journal with her collaborators. She has written chapters in diagnostic cytology, molecular processes in breast pathology and on Her 2 testing.

Mary is the Clinical Director for Pathology at UCLH, an Associate Clinical Professor at UCL, an Associate Responsible Officer and lead appraiser at UCLH and the Designated Individual for the HTA for the postmortem service.