Humberto E. Trejo Bittar, MD
Assistant Professor of Pathology

Dr. Trejo Bittar is a member of the Division of Anatomic Pathology with a subspecialty interest in thoracic pathology.

Office Information:
Room C605
UPMC Presbyterian Hospital
Department of Pathology
200 Lothrop Street
Pittsburgh, PA 15213
Contact Information:
Telephone: 412-647-6203


  • MD - Universidad Central de Venezuela, Escuela de Medicina "Luis Razetti", Caracas, 2004
  • Post-Doctoral Fellowship – Northwestern University, Chicago, 2012
  • Anatomic Pathology Residency – University of Pittsburgh Medical Center, 2015
  • Thoracic Pathology Fellowship - University of Pittsburgh Medical Center, 2016

Clinical Expertise

Dr. Trejo Bittar is a surgical pathologist with a subspecialty focus in Thoracic Pathology at the University of Pittsburgh Medical Center, Presbyterian Hospital. His diagnostic skills include both neoplastic and non-neoplastic thoracic pathology, with emphasis in non-neoplastic pathology.

Research Interests

Dr. Trejo Bittar's research interest centers on the pathology of inflammatory lung diseases. He has a particular interest on the pathologies of the small airways. Currently, in conjunction with his mentors Dr. Samuel Yousem and Dr. Sally Wenzel, Dr. Trejo Bittar has further characterized the morphologic features of asthmatic granulomatosis. He has multiple research projects ongoing on the physiopathology of severe asthma and the role of digital pathology in quantitative counting of inflammatory cells in lung tissue.


  • Certification in Anatomic Pathology, American Board of Pathology, 2015


Thoracic Pathology

Awards and Honors

  • American Heart Association Midwest Affiliate Post-Doctoral Fellowship Grant, 2009-2011
  • Chief Fellow, UPMC Department of Pathology, 2015-2016

Selected Publications

View Dr. Trejo Bittar's publications on PubMed

  • Trejo Bittar HE, Yousem S, Wenzel S. Pathobiology of severe asthma. Annual Review of Pathology. 2015 February (10): 511-45.
  • Trejo Bittar HE, Bastacky S, Singhi A. Prostatic Adenocarcinoma Metastatic to the Pancreas: a Case Series and Review of the Literature. In press.
  • Trejo Bittar HE, Pantanowitz L. Merkel Cell Polyomavirus Is Not Detected in Lung Adenocarcinomas by Immunohistochemistry. Appl Immunohistochem Mol Morphol. 2015 Aug 25.
  • Trejo Bittar HE, Incharoen P, Althouse AD, Dacic S. Accuray of the IASCL/ATS/ERS Histological Subtyping of Stage I Lung Adenocarcinoma on Intraoperative Frozen Sections. Mod Pathol. 2015 Aug;28(8):1058-1063.
  • Doberer D, Trejo Bittar HE, Wenzel S. Should lung biopsies be performed in patients with severe asthma? Eur Respir Rev. 2015 Sep;24(137):525-39.
  • Wang P, Bahreini A, Gyanchandani R, Lucas PC, Hartmaier RJ, Watters RJ, Jonnalagadda AR, Trejo Bittar HE, Berg A, Hamilton RL, Kurland BF, Weiss KR, Mathew A, Leone JP, Davidson NE, Nikiforova MN, Brufsky AM, Ambros TF, Stern AM, Puhalla SL, Lee AV, Oesterreich S.Sensitive detection of mono- and polyclonal ESR1 mutations in primary tumors, metastatic lesions and cell free DNA of breast cancer patients. Clin Cancer Res. 2015 Oct 23
  • Trejo Bittar HE, Dada LA, Welch LC, Vagin O, Deiss-Yehiely N, Kelly AM, Baker MR, Capri J, Cohn W, Whitelegge JP, Vadász I, Gruenbaum Y, Sznajder JI. High CO2 Leads to Na,K-ATPase Endocytosis via c-Jun Amino-Terminal Kinase-Induced LMO7b Phosphorylation. Mol Cell Biol. 2015 Dec;35(23):3962-73.
  • Dewan R, Trejo Bittar HE, Lacomis J, Ocak I. Granulomatosis with Polyangiitis Presenting with Coronary Artery and Pericardial Involvement. Case Rep Radiol. 2015;2015:516437. doi: 10.1155/2015/516437. Epub 2015 Dec 22.
  • Helenius IT, Nair, Trejo Bittar HE, Sznajder JI, Sporn PH, Beitel GJ.Focused Screening Identifies Evoxine as a Small Molecule That Counteracts CO2-Induced Immune Suppression. J Biomol Screen. 2016 Apr;21(4):363-71.
  • Tan J, Tedrow JR, Dutta JA, Juan-Guardela B, Nouraie M, Chu Y, Trejo Bittar H, Ramani K, Biswas PS, Veraldi KL, Kaminski N, Zhang Y, Kass DJ. Expression of RXFP1 is Decreased in Idiopathic Pulmonary Fibrosis: Implications for Relaxin-Based Therapies. Am J Respir Crit Care Med. 2016 Jun 16.