Alexa Siddon, MD
Professor of Laboratory MedicineCards
About
Research
Publications
2026
Joining the National Resident Matching Program Fellowship Match: the hematopathology experience
Courville E, Seifert R, Sadigh S, Chen X, Calli J, Hasserjian R, Siddon A. Joining the National Resident Matching Program Fellowship Match: the hematopathology experience. Academic Pathology 2026, 13: 100230. DOI: 10.1016/j.acpath.2025.100230.Peer-Reviewed Original Research
2025
ASCP Board of Certification survey of Medical Laboratory Science education 2023: programs
Duzan D, Fong K, Freeman V, Goodyear N, Nadder T, Siddon A, Spiczka A, Taff T, Tanabe P. ASCP Board of Certification survey of Medical Laboratory Science education 2023: programs. Lab Medicine 2025, lmaf069. PMID: 41273160, DOI: 10.1093/labmed/lmaf069.Peer-Reviewed Original ResearchASCP Board of Certification survey of Medical Laboratory Technician education 2023: faculty and programs
Duzan D, Fong K, Freeman V, Goodyear N, Nadder T, Siddon A, Spiczka A, Taff T, Tanabe P. ASCP Board of Certification survey of Medical Laboratory Technician education 2023: faculty and programs. Lab Medicine 2025, lmaf071. PMID: 41240385, DOI: 10.1093/labmed/lmaf071.Peer-Reviewed Original ResearchLarge language models mediated extraction of clinical information from bone marrow biopsy pathology reports
Lanino L, Getz T, Kewan T, Kiwan A, Rolles B, Bidikian A, Sariipek N, Mendez L, Podoltsev N, Durant T, Meeker D, Perincheri S, Gershkovich P, Katz S, Siddon A, Xu M, Bewersdorf J, Della Porta M, Zeidan A, Stahl M. Large language models mediated extraction of clinical information from bone marrow biopsy pathology reports. Blood 2025, 146: 2555. DOI: 10.1182/blood-2025-2555.Peer-Reviewed Original ResearchMedical record numberElectronic health recordsLanguage modelExtraction accuracyBlast countAutomated extractionBiopsy pathology reportConfidence intervalsExtraction of clinical informationHallucination ratingsPathology reportsRule-based algorithmReal-world dataSystematically extract informationClinical researchCategorical variablesFibrosis gradeZero-ShotUnprocessed textRinged sideroblastsExpert systemHealth recordsContinuous variablesSpearman correlation coefficientCode adjustmentPrognostic impact of cytogenetic abnormalities in aggressive T-cell lymphomas: Defining high-risk subgroups through conventional karyotyping.
Kiwan A, Diadamo A, Wen J, Kewan T, Siddon A, Kothari S, Isufi I, Seropian S, Huntington S, Montanari F, Xu M, Li P, Girardi M, Sethi T, Foss F. Prognostic impact of cytogenetic abnormalities in aggressive T-cell lymphomas: Defining high-risk subgroups through conventional karyotyping. Blood 2025, 146: 1759-1759. DOI: 10.1182/blood-2025-1759.Peer-Reviewed Original ResearchT-cell lymphomaMature T-cell lymphomasAggressive T-cell lymphomaUnivariate Cox proportional hazardsMonosomy 9Overall survivalPeripheral bloodMonosomy 5Nodal PTCLBone marrowHigh-risk subgroupsPrognostic significancePlatelet countCox proportional hazardsCytogenetic abnormalitiesPrognostic impactComplex karyotypeT cellsMarker chromosomesPrognostic impact of cytogenetic abnormalitiesPredictor of poor OSImpact of cytogenetic abnormalitiesMultivariate CPH modelChromosomal lesionsPresence of marker chromosomesAberrant circulating CD4+ CD26- T-cells in T-cell rich B-cell lymphomas: Diagnostic pitfall or biomarker?
Ravishankar A, Chen P, Xu M, Braddock D, Siddon A, Isufi I, Huntington S, Seropian S, Foss F, Kothari S, Sethi T. Aberrant circulating CD4+ CD26- T-cells in T-cell rich B-cell lymphomas: Diagnostic pitfall or biomarker? Blood 2025, 146: 7182. DOI: 10.1182/blood-2025-7182.Peer-Reviewed Original ResearchNodular lymphocyte-predominant Hodgkin lymphomaT-cell/histiocyte-rich large B-cell lymphomaB-cell lymphomaT cell populationsT-cell-rich B-cell lymphomaT-cell clonalityT cellsPeripheral bloodHodgkin lymphomaYounger patientsDiagnostic pitfallsB cellsSensitivity to PD-1 blockadeT-cell non-Hodgkin's lymphomaCD4+ T cell subsetsAberrant T-cell populationLymphocyte-predominant Hodgkin lymphomaT-cell-rich backgroundAggressive B-cell lymphomasLarge B-cell lymphomaRepertoire analysisAbnormal T-cell populationCohort of young patientsCD26- T cellsDiagnostic lymph nodesMulticenter assessment of absolute neutrophil counts (ANC) and white blood cell counts (WBC) in healthy participants with the erythrocyte duffy null phenotype or genotype
Merz L, Attipoe G, Barriteau C, Blechner M, Burks E, Calhoun C, Lee S, Chang V, Chou S, Cuker A, Fadeyi E, Fingrut W, Forbes V, Francischetti I, Gadi V, Godby R, Godley L, Haimed A, Han H, Haspel R, Ilonze C, Jacquot C, Ji P, Juskewitch J, Karafin M, Klein K, Kucine N, Kumar P, Kushnir M, Levitz D, Lewis M, Li G, Mei Z, Brzostek S, Rose G, Schultz C, Siddon A, Sillings C, Sloan J, Soni A, Stevens D, Story C, Szymanski J, Takemoto C, Thompson A, Warsame R, Weyand A, Wilson S, Zaghloul N, Belay Y, Fink A, Frustace P, Tyson J, Van Havre N, Achebe M. Multicenter assessment of absolute neutrophil counts (ANC) and white blood cell counts (WBC) in healthy participants with the erythrocyte duffy null phenotype or genotype. Blood 2025, 146: 1074. DOI: 10.1182/blood-2025-1074.Peer-Reviewed Original ResearchMedian white blood cell countWhite blood cell countWhite blood cell count dataDuffy null phenotypeMulticenter assessmentConfidence intervalsNon-HispanicAfrican AmericansClinical and Laboratory Standards Institute guidelinesReference intervalsLaboratory Standards Institute guidelinesAbsolute neutrophil countMann-Whitney U testBlood cell countHealthy participantsKruskal-Wallis testMedian ageNo significant differenceNull phenotypeNeutrophil countULNConsistent with prior dataSample collection typePractice settingsHealthcare systemHypomethylating Agent and Venetoclax Combination Is a Safe and Effective Alternative to Intensive Chemotherapy in Older (≥ 70 Years) Patients With Newly Diagnosed Favorable Risk Acute Myeloid Leukemia
Ball S, Jain A, Al Ali N, Aguirre L, Bewersdorf J, Kent A, Rose A, Hayden A, Siddon A, Lykon J, Madarang E, Swoboda D, Padron E, Sweet K, Sallman D, Lancet J, Carraway H, Watts J, Zeidan A, Pollyea D, Komrokji R. Hypomethylating Agent and Venetoclax Combination Is a Safe and Effective Alternative to Intensive Chemotherapy in Older (≥ 70 Years) Patients With Newly Diagnosed Favorable Risk Acute Myeloid Leukemia. American Journal Of Hematology 2025, 100: 1920-1923. PMID: 40772639, DOI: 10.1002/ajh.70031.Peer-Reviewed Original Research382 | GENE COPY NUMBER ALTERATIONS IDENTIFY SUBSET OF SEZARY SYNDROME PATIENTS WITH WORSE SURVIVAL OUTCOMES
Kiwan A, Foss F, Girardi M, Xu M, Siddon A, Sethi T. 382 | GENE COPY NUMBER ALTERATIONS IDENTIFY SUBSET OF SEZARY SYNDROME PATIENTS WITH WORSE SURVIVAL OUTCOMES. Hematological Oncology 2025, 43 DOI: 10.1002/hon.70094_382.Peer-Reviewed Original ResearchHeterogeneity in outcomes of TP53‐mutated myeloproliferative neoplasms based on disease phenotype and mutational status
Badar T, Foran J, Bewersdorf J, Wang Y, Coltoff A, Kettani M, Shah K, Oliva F, Lin C, Jamy O, Diebold K, Shallis R, Siddon A, Katkov D, Schoen A, Khan I, Foucar C, Atallah E, Goldberg A, Patel A. Heterogeneity in outcomes of TP53‐mutated myeloproliferative neoplasms based on disease phenotype and mutational status. British Journal Of Haematology 2025, 207: 683-686. PMID: 40400334, DOI: 10.1111/bjh.20187.Peer-Reviewed Original Research
Academic Achievements & Community Involvement
Clinical Care
Overview
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.
Clinical Specialties
Fact Sheets
Cytogenic Studies for Leukemia Diagnosis
Learn More on Yale MedicineDiagnosing Leukemia
Learn More on Yale Medicine
Board Certifications
Hematology (Pathology)
- Certification Organization
- AB of Pathology
- Original Certification Date
- 2013
Anatomic & Clinical Pathology
- Certification Organization
- AB of Pathology
- Original Certification Date
- 2012
News
News
- June 12, 2025
Pathology, Laboratory Medicine Residents, Fellows Feted at Graduation Ceremony
- March 27, 2025
Yale Pathologists Share Insight, Latest Research at USCAP 2025
- October 21, 2024Source: MedTech Dive
5 steps to navigate the FDA's new lab developed test rule
- September 12, 2024
Alexa Siddon Receives ASCP Distinguished Educator Award
Get In Touch
Contacts
Laboratory Medicine
330 Cedar Street, PO Box 208035
New Haven, CT 06520-8035
United States
Locations
Department of Laboratory Medicine
Academic Office
55 Park Street, Rm 435B
New Haven, CT 06511
Clinical Inquiry
203.688.4977
Events
Everyone William Morice II, MD, PhD