N. Paul Ohori, MD

Professor of Pathology, Division of Anatomic Pathology

Dr. Ohori is Medical Director of Cytopathology at UPMC-Presbyterian.  He specializes in Non-Gynecologic Cytopathology with a focus in thyroid, pancreatobiliary, and pulmonary areas.  He is recognized internationally for his research in thyroid cytopathology and is a member of the Bethesda System for Reporting Thyroid Cytopathology.

Clinical Expertise

  • Head and Neck and Thoracoabdominal Cytopathology
  • Pulmonary Pathology
  • Application of Ancillary Testing to Cytopathology


  • Anatomic and Clinical Pathology from the American Board of Pathology
  • Cytopathology from the American Board of Pathology
Education & Training
BA with Honors - Johns Hopkins University
MD - Medical College of Virginia
Pathology Residency - Hospitals of the University Health Care Center of Pittsburgh (UPMC)
Residency Program Director’s Award. UPMC-Presbyterian Cytopathology Rotation, 2003.
Top cited article in Cancer Cytopathology, 2010.
International Award for Publishing Excellence in The Journal of Clinical Endocrinology and Metabolism, 2012.
Advances in Thyroid Cytology Award at the Annual Scientific Meeting of the American Society of Cytopathology, 2018.
Research Interests

Dr. Ohori’s research interests have focused on clinicopathologic, cytopathologic, and molecular correlation of thyroid, pancreas, pulmonary diseases to develop better understanding and application of techniques to practice.  In addition, he participates in research in quality assurance and resident and fellow training.

Representative Publications

View Dr. Ohori's publications on PubMed.

Selected Publications

  1. Ohori NP. FNA Cytopathology and Molecular Test Characteristics in the Changing Landscape of Papillary Thyroid Carcinoma. J Basic Clin Med 2015;4:103-9.
  2. Yip L, Nikiforova MN, Yoo JY, McCoy KL, Stang MT, Armstrong MJ, Nicholson KJ, Ohori NP, Coyne C, Hodak SP, Ferris RL, LeBeau SO, Nikiforov YE, Carty SE. Tumor Genotype Determines Phenotype and Disease-related Outcomes in Thyroid Cancer: A Study of 1510 Patients. Ann Surg. 2015;262:519-25.
  3. Nikiforov YE, Carty SE, Chiosea SI, Coyne C, Duvvuri U, Ferris RL, Gooding WE, LeBeau SO, Ohori NP, Seethala RR, Tublin ME, Yip L, Nikiforova MN. Impact of the Multi-Gene ThyroSeq Next-Generation Sequencing Assay on Cancer Diagnosis in Thyroid Nodules with Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance Cytology. Thyroid. 2015;25:1217-23.
  4. Ohori NP, Radkay LA, Macpherson TA, Yousem SA, Schoedel KE.  Changes in Resident Graduate Characteristics in a Large Pathology Training Program, 1994-2013.  Academic Pathology.  2016;3:1-6.
  5. Michael CW, Hoda RS, Saqi A, Kazakov J, Elsheikh T, Azar N, Ohori NP.  Committee I: Indications for Pulmonary Cytology Sampling Methods.  Diagn Cytopathol. 2016;44:1010–1023.
  6. Patel SG, Carty SE, McCoy KL, Ohori NP, LeBeau SO, Seethala RR, Nikiforova MN, Nikiforov YE, Yip L.  Preoperative Detection of RAS Mutation May Guide Extent of Thyroidectomy.  Surgery. 2017;161:168-175.
  7. Ohori NP, Wolfe J, Carty SE, Yip L, LeBeau SO, Berg AN, Schoedel KE, Nikiforov YE, Seethala RR.  The influence of the noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) resection diagnosis on the false-positive thyroid cytology rate relates to quality assurance thresholds and the application of NIFTP criteria.  Cancer Cytopathol. 2017;125:692-700.
  8. Singhi AD, McGrath K, Brand RE, Khalid A, Zeh HJ, Chennat JS, Fasanella KE, Papachristou GI, Slivka A, Bartlett DL, Dasyam AK, Hogg M, Lee KK, Marsh JW, Monaco SE, Ohori NP, Pingpank JF, Tsung A, Zureikat AH, Wald AI, Nikiforova MN.  Preoperative next-generation sequencing of pancreatic cyst fluid is highly accurate in cyst classification and detection of advanced neoplasia.  Gut. 2018;67:2131-2141.
  9. Dhir M, McCoy KL, Ohori NP, Adkisson CD, LeBeau SO, Carty SE, Yip L. Correct extent of thyroidectomy is poorly predicted preoperatively by the guidelines of the American Thyroid Association for low and intermediate risk thyroid cancers.  Surgery. 2018;163:81-87.
  10. Bo W, Schoedel KE, Carty SE, Radkay LA, Ohori NP, Nikiforov YE, Nikiforova MN, Yip L.  Incidental Diagnosis of Parathyroid Lesions by Preoperative Use of Next-Generation Molecular Testing. World J Surg. 2018;42:2840-2845.
  11. Mon SY, Riedlinger G, Abbott CE, Seethala R, Ohori NP, Nikiforova MN, Nikiforov YE, Hodak SP. Cancer risk and clinicopathological characteristics of thyroid nodules harboring thyroid-stimulating hormone receptor gene mutations. Diagn Cytopathol. 2018;46:369-377.
  12. Welborn SL, Ohori NP, Nason KS, Pennathur A, Awais O, Christie NA, Luketich JD, Schuchert MJ. Percutaneous CT-guided biopsy performed by thoracic surgeons in 955 patients: a paradigm shift in image-guided thoracic procedures.  Journal of Thoracic and Cardiovascular Surgery. 2019;157:1239-1245.
  13. Ohori NP, Landau MS, Carty SE, Yip L, LeBeau SO, Manroa P, Seethala RR, Schoedel KE, Nikiforova MN, Nikiforov YE.  Benign Call Rate and Molecular Test Result Distribution of ThyroSeq v3.  Cancer Cytopathol. 2019;127:161-168.
  14. Nikiforova MN, Nikiforov YE, Ohori NPGLIS rearrangements in thyroid nodules: A key to preoperative diagnosis of hyalinizing trabecular tumor.  Cancer Cytopathol. 2019;127:560-566.
  15. Landau MS, Pearce TM, Carty SE, Wolfe J, Yip L, McCoy KL, LeBeau SO, Tublin ME, Ohori NPComparison of the collection approaches of 2 large thyroid fine-needle aspiration practices reveals differing advantages for cytology and molecular testing adequacy rates.  J Am Soc Cytopathol.  2019;8:243-249.
  16. Singhi AD, Nikiforova MN, Chennat J, Papachristou GI, Khalid A, Rabinovitz M, Das R, Sarkaria S, Ayasso MS, Wald AI, Monaco SE, Nalesnik M, Ohori NP, Geller D, Tsung A, Zureikat AH, Zeh H, Marsh JW, Hogg M, Lee K, Bartlett DL, Pingpank JF, Humar A, Bahary N, Dasyam AK, Brand R, Fasanella KE, McGrath K, Slivka A.  Integrating next-generation sequencing to endoscopic retrograde cholangiopancreatography (ERCP)-obtained biliary specimens improves the detection and management of patients with malignant bile duct strictures.  Gut. 2020;69:52-61.
  17. Ohori NP, Landau MS, Manroa P, Schoedel KE, Seethala RR. Molecular-derived estimation of risk of malignancy for indeterminate thyroid cytology diagnoses. J Am Soc Cytopathol. 2020;9:213-220.
  18. Ohori NP.  Molecular testing and thyroid nodule management in North America.  Gland Surg 2020;9:1628-1638.
  19. Carty SE, Ohori NP, Hilko DA, McCoy KL, French EK, Manroa P, Morariu E, Sridharan S, Seethala RR, Yip L. The Clinical Utility of Molecular Testing in the Management of Thyroid Follicular Neoplasms (Bethesda IV Nodules). Ann Surg. 2020;272:621-627.
  20. Rea B, Peel RL, Han M, Ohori NP, Aggarwal N. Intravascular Large B-Cell Lymphoma Involving Multinodular Goiter and Mimicking Carcinoma.  Int J Surg Pathol. 2020;28:517-518.
  21. Nikiforova MN, Lepe M, Tolino LA, Miller ME, Ohori NP, Wald AI, Landau MS, Kaya C, Malapelle U, Bellevicine C, Troncone G, Nikiforov YE, Baloch Z. Thyroid cytology smear slides: An untapped resource for ThyroSeq testing. Cancer Cytopathol. 2021;129:33-42.
  22. Doerfler WR, Nikitski AV, Morariu EM, Ohori NP, Chiosea SI, Landau MS, Nikiforova M, Nikiforov YE, Yip L, Manroa P. Molecular alterations in Hürthle cell nodules and preoperative cancer risk. Endocr Relat Cancer. 2021;28:301-309.
  23. Landau MS, Nikiforov YE, Ohori NP, Chiosea SI.  Impact of molecular testing on detecting mimics of oncocytic neoplasms in thyroid fine-needle aspirates diagnosed as follicular neoplasm of Hürthle cell (oncocytic) type. Cancer Cytopathol. 2021;129:788-797.
  24. Xing J, Khader SN, Ohori NP, DeFrances M, Cuda J, Monaco SE. Comparison of quantitative internal and external measures of performance for trainees in cytopathology fellowships.  J Am Soc Cytopathol. 2021;10:495-503.
  25. Das R, McGrath K, Seiser N, Smith K, Uttam S, Brand RE, Fasanella KE, Khalid A, Chennat JS, Sarkaria S, Singh H, Slivka A, Zeh HJ, Zureikat AH, Hogg ME, Lee K, Paniccia A, Ongchin MC, Pingpank JF, Boone BA, Dasyam AK, Bahary N, Gorantla VC, Rhee JC, Thomas R, Ellsworth S, Landau MS, Ohori NP, Henn P, Shyu S, Theisen BK, Singhi AD.   Tumor Size Differences Between Preoperative Endoscopic Ultrasound and Postoperative Pathology for Neoadjuvant-Treated Pancreatic Ductal Adenocarcinoma Predict Patient Outcome. Clin Gastroenterol Hepatol. 2022;20:886-897.
  26. Ohori NPA Decade Into Thyroid Molecular Testing: Where Do We Stand?  J Am Soc Cytopathol. J Am Soc Cytopathol. 2022;11:59-61.
  27. Geisler DL, Nestler RJ, Mosley BL, Walko AL, Cuda JM, Schoedel KE, Davison JM, Ohori NP. Accuracy of Definitive Rapid On-site Evaluation Cytopathology Diagnoses: Assessment of Potentially Critical Diagnoses as a Quality Assurance Measure.  J Am Soc Cytopathol. 2022;11:133-141.