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Alexa Siddon, MD

Pathology, Hematology & Oncology, Hematopathology, Pediatric Hematology & Oncology, Genetics


Alexa Siddon, MD, is a pathologist who specializes in diagnosing diseases of the blood, such as leukemia and disorders, including bone marrow failure. Her interest in medicine began at a young age, when she accompanied her mother to the workplace—a clinical laboratory. In college, Dr. Siddon completed emergency medical technician (EMT) training and, later, decided to attend medical school. 

“I chose pathology because I enjoy putting together the entire story of a patient to make a diagnosis,” says Dr. Siddon, who directs the hemopathology lab at the Veteran Affairs Connecticut Healthcare System. When examining patient samples, Dr. Siddon relies on an arsenal of sophisticated tools to make an accurate diagnosis. “For example, we might look at a bone marrow sample under a microscope, and we would also do genetic sequencing to see if we can discover genetic mutations that might make the patient eligible for a clinical trial.” 

“My main focus is patient care,” Dr. Siddon says. “The more information I can give our colleagues, including hematology oncologists, the better care they can provide.” 

At Yale School of Medicine, Dr. Siddon is an assistant professor of laboratory medicine. 


  • Associate Professor Term
  • Hematopathology Fellowship Director, Laboratory Medicine
  • Co-Director, Molecular Diagnostics Laboratory, Laboratory Medicine
  • Associate Director, Flow Cytometry, Laboratory Medicine
  • Associate Director, Hematology Laboratory, Laboratory Medicine

Education & Training

  • Fellowship
    Yale University School of Medicine (2013)
  • Residency
    Yale University School of Medicine (2012)
  • MD
    SUNY Upstate Medical University (2008)
  • BA
    Hamilton College (2004)

Additional Information