Lydia Howell, M.D.

Lydia Pleotis Howell, M.D.


Pathology and Laboratory Medicine

Pathology - Cytopathology


  • Professor and Chair, Pathology and Laboratory Medicine
To see if Lydia Pleotis Howell is accepting new patients, or for assistance finding a UC Davis doctor, please call 800-2-UCDAVIS (800-282-3284).

Pathology Building

4400 V St.
Sacramento, CA 95817
Driving Directions

Primary Phone:

Additional Phone Numbers

Physician Referrals: 800-4-UCDAVIS (800-482-3284)

Clinical Interests

Lydia Howell is an anatomic and clinical pathologist well known for her work to improve protocols for prevention, diagnosis and treatment of breast and cervical cancer.

Howell provides clinical service in cytopathology, fine-needle aspiration biopsy and surgical pathology. Her clinical and research interests focus on early detection of breast and cervical disease, including cervical cancer screening, HPV testing, breast screening, cancer risk assessment, diagnosis and prognostication, evaluation of new technologies in cytopathology, workforce and faculty development issues.

Research/Academic Interests

As chair of the Department of Pathology and Laboratory Medicine, Howell oversees nearly 50 faculty members and more than 400 clinical and academic staff who provide comprehensive laboratory testing for UC Davis Medical Center and other hospitals and clinics through Northern California, conduct leading-edge basic and translational research, and advance training at all levels within the field.

A pioneer in new techniques for cervical cancer screening, Dr. Howell has provided leadership in standardizing practices that improve quality and outcomes through her participation in national consensus conferences and panels.

Known for her commitment to faculty development, Dr. Howell served as co-principal investigator for a $1.27 M NIH grant studying the effect of family-friendly policies on women’s careers in medicine. She is the project leader for an Innovation Award for faculty career flexibility from the American Council on Education and the Sloan Foundation.


Anatomic Pathology

Center/Program Affiliation

UC Davis Comprehensive Cancer Center


M.D., Northwestern University School of Medicine, Chicago, Illinois, 1981

B.S., Northwestern University Medical School, Evanston, Illinois, 1979


Temple University Hospital, Philadelphia, Pennsylvania, 1981-1985


Lankenau Hospital, Philadelphia, Pennsylvania, 1985-1986

Board Certifications

American Board of Pathology, Anatomic and Clinical Pathology, 1986

American Board of Pathology, Cytopathology, 1989

Professional Memberships

American Medical Association

American Society of Clinical and Colposcopic Pathology

American Society of Clinical Pathology

American Society of Cytopathology

College of American Pathologists

United States and Canadian Academy of Pathology

Honors and Awards

Included in "Best Doctors in the Region," Sacramento Magazine, 2001

Christine Landgraf Memorial Research Award, 1993

Select Recent Publications

McGahan JP, Bishop J, Webb J, Howell L, Torok N, Lamba R, MT. Role of FNA and core biopsy of primary and metastatic liver disease. Internat J Hepatology 2013; Article ID 174103, 10 pages, 2013. doi:10.1155/2013/174103.

Auger M,  Khalbuss WE, Souers R, Nayar R, Benedict CC, Howell LP, Tambouret R. Implementation of The Bethesda System for Reporting Thyroid Cytopathology: observations from the 2011 Thyroid Supplemental Questionnaire of the College of American Pathologists. Arch Pathol Lab Med 2013; 137:1555-9

Elson SA, Hiatt RL, Anton-Culver H, Howell LP, Naiem A, Parker BA, Vant Veer LJ, Hogarth M, Pierce JP, Duwors RJ, Hagopoulos K, Esserman LJ, Athena Breast Health Network. The Athena Breast Health Network:  Developing a rapid learner system for breast cancer prevention, screening, treatment, and care.  Breast Cancer Res Treatment 2013; 140:417-425.

Howell LP, Darragh TE, Souers R, Thomas N, Moriarty AT. Identification of Trichomonas vaginalis in different Pap test preparations: Trends over time in the College of American Pathologist’s Educational Inter-laboratory Comparison Program. Arch Pathol Lab Med 2013; 137:1043-1046.

Villablanca AC, Beckett L, Nettiksimmons J, Howell LP.  Improving awareness, knowledge and use of career flexibility options at the University of California Davis, School of Medicine. Acad Med 2013; 88:771-777.

Howell LP, Savaloga L, Nayar R, Tabbara S, Thomas N, Winkler B, Tworek J. The role of proficiency testing in ensuring quality: Findings from the College of American Pathologists Gynecologic Cytopathology Quality Consensus Conference.  Arch Pathol Lab Med 2013:. 132: 183-189

Tworek J, Savaloga L, Nayar R, Tabbara S, Thomas N, Winkler B, Howell LP. General quality practices in gynecologic cytopathology: findings from the College of American Pathologists Gynecologic Cytopathology Quality Conference. Arch Pathol Lab Med 2013; 132:190-198

Darragh TM, Colgan TJ, Cox T, Heller DS,  Henry MR, Luff RD, McCalmont T, Nayar R Palefsky JM, Stoler MH, Wilkinson EJ, Zaino RJ, Wilbur DC, and Members of the LAST Project Workgroups (includes Howell LP).   The lower anogenital squamous teriminolog standardization project for HPV-associated lesions: background and consensus recommendations from the College of American Pathologists and the American Society of Cervical and Colposcopic Pathology. Arch Pathol Lab Med 2012; 136:1266-97.

Howell LP, Beckett LA, Nettiksimmons J, Villablanca A. Generational and gender perspectives toward career flexibility: an approach to ensuring the faculty workforce of the future.  AJM 2012, 125:719-728.

Villablanca AC, Beckett L, Nettiksimmons J, Howell LP.  Attitudes, awareness and use of family-friendly policies for career flexibility: an NIH-OWHR funded study to enhance women’s careers in biomedical science.  J Women’s Health 2011; 20:1485-1496.