About

Zhaohai Yang, MD, PhD, is a Professor of Clinical Pathology and Laboratory Medicine at the University of Pennsylvania. He is an attending pathologist within the University of Pennsylvania Health System and serves as the Director of the GI/liver Pathology Fellowship Program at the same institution. His research centers on neoplastic diseases of the luminal gastrointestinal tract, liver, biliary tract, and pancreas, with a particular focus on neuroendocrine tumors of the digestive system. Dr. Yang specializes in gastrointestinal, pancreas, and liver pathology, contributing to both clinical practice and academic research in these areas.

Research topics

• Pathology
• Medicine
• Biology
• Internal medicine
• Gastroenterology

Selected publications

• Type of submucosal injection solution for endoscopic resection of large colon polyps – results of a randomized trial

  Endoscopy · 2025-03-01

  article
  PublisherDOI

• 681 Gastrointestinal Neuroendocrine Carcinoma Associated with Adenoma: A Tumor More Aggressive than Neuroendocrine Carcinoma Mixed with Adenocarcinoma

  Laboratory Investigation · 2025-03-01

  articleOpen access
  PublisherOA PDFDOI

• 631 Interrater and Intergroup Variability in Colorectal Mass Biopsy Interpretation: Implications for Gastrointestinal Pathology Fellowship Training

  Laboratory Investigation · 2025-03-01

  article
  PublisherDOI

• Indefinite for dysplasia in Barrett’s esophagus carries substantial risk for prevalent and incident neoplasia: updated outcomes and long-term follow-up

  Gastrointestinal Endoscopy · 2025-04-25 · 2 citations

  articleOpen access

  BACKGROUND AND AIMS: The optimal management of patients with Barrett's esophagus (BE) that is indefinite for dysplasia (IND) is unclear because of uncertain risks of progression to low-grade dysplasia (LGD), high-grade dysplasia (HGD), and esophageal adenocarcinoma (EAC). In this study, we aimed to define the risks of neoplasia among patients IND, including long-term follow-up of our previously described cohort, and to identify risk factors for progression to neoplasia. METHODS: Patients IND from 2000 to 2023 were identified from the University of Pennsylvania Health System pathology database and the BE patient registry. Prevalent neoplasia was defined as LGD, HGD, or EAC occurring within 1 year of the index EGD. Incident neoplasia occurred >1 year after the index EGD. Time to neoplasia was analyzed with the Cox proportional hazards regression model. Risk factors for neoplasia were identified using logistic and Cox regression. RESULTS: Of 299 identified patients, 223 had a follow-up EGD within 1 year. Of these 223 patients, 9.87% had prevalent neoplasia of any grade: LGD in 3.14%, HGD in 5.38%, and EAC in 1.35%. Two hundred seventeen patients without prevalent neoplasia had an EGD after 1 year, with a median follow-up of 4.37 years (IQR, 2.62-8.15); 22% developed incident neoplasia. The incidence of any neoplasia was 4.35 per 100 person-years: 2.43 for LGD, 1.24 for HGD, and 0.47 for EAC. BE length and smoking were associated with incident neoplasia (hazard ratio, 1.13 [95% CI, 1.03-1.25] and 2.01 [95% CI, 1.12-3.80], respectively). CONCLUSIONS: IND carries substantial risk for progression to neoplasia including HGD and EAC, especially in the first year after diagnosis. Incident HGD and EAC risk approximates that published for LGD.

  PublisherOA PDFDOI

• 1602 Pancreatobiliary and Ampullary Mixed Neuroendocrine Non-neuroendocrine Neoplasms: Any Percentage of Neuroendocrine Carcinoma is Aggressive

  Laboratory Investigation · 2025-03-01

  articleOpen access
  PublisherOA PDFDOI

• Clinicopathologic Features of Untreated Colorectal Cancer with Acellular Mucin–Only Lymph Nodes

  Modern Pathology · 2025-06-11

  articleOpen access
  PublisherOA PDFDOI

• Composite gangliocytoma/neuroma and neuroendocrine tumour: a contemporary analysis of 71 cases shows risk factors for metastasis

  Histopathology · 2025-08-12 · 2 citations

  articleOpen access

  AIMS: To describe the clinicopathological features of composite gangliocytoma/neuroma and neuroendocrine tumour (CoGNET) and possible risk factors for nodal metastasis. METHODS AND RESULTS: We compiled a cohort of 71 cases from 19 institutions. Mean patient age was 58 years. Thirty-eight (54%) patients were male. Most patients (65%) had symptoms, including abdominal pain (20%) and gastrointestinal bleeding (19%). Most cases (70%) were described as a subepithelial mass/nodule, and nearly half (45%) were located in the 2nd portion of the duodenum. Mean tumour size was 2.2 cm, and most (87%) were well-circumscribed. Nearly all cases (96%) demonstrated all three histologic components, with the epithelioid component being the most predominant overall (mean 59%). All cases involved the submucosa, with 7 (10%) additionally involving the muscularis propria. Solid areas of ganglion-like cells were identified in 16/69 (23%) cases, glandular structure formation in 15/70 (21%), lymphovascular invasion (LVI) in 6/70 (9%) cases, and perineural invasion and necrosis in one case each. Nodal metastasis was identified at diagnosis in 8 (11%) cases; increased age, increased size, LVI and muscularis propria involvement were all significantly associated with nodal disease (P < 0.05). Follow-up data were available for 68 patients (mean 47 months); nearly all were alive without disease, though one patient developed liver metastasis after 8 months and died of the disease after 63 months. CONCLUSIONS: This largest series of CoGNET to date demonstrates that approximately 10% of cases develop nodal metastases. Large tumour size, muscularis propria involvement, advanced patient age and LVI appear to be risk factors for nodal metastasis.

  PublisherOA PDFDOI

• 1462 Primary Hepatic Solitary Fibrous Tumors: A Multi-Institutional Study on Clinicopathologic Characteristics and Risk Stratification

  Laboratory Investigation · 2025-03-01

  articleOpen access
  PublisherOA PDFDOI

• 697 Gastrointestinal Mixed Neuroendocrine Non-Neuroendocrine Neoplasm: Assessment of the Validity of the 30% Requirement for Both Components

  Laboratory Investigation · 2025-03-01

  articleOpen access
  PublisherOA PDFDOI

• 706 Comprehensive Clinicopathological Analysis of Sloughing esophagitis: A Large-Scale Single-center Study

  Laboratory Investigation · 2025-03-01

  articleSenior author
  PublisherDOI

Frequent coauthors

• Wafik S. El‐Deiry

  Brown University

  95 shared

• Thomas A. Milne

  University of Oxford

  50 shared

• Jay L. Hess

  University of Michigan–Ann Arbor

  50 shared

• Miriam Kunkel

  Penn State Milton S. Hershey Medical Center

  48 shared

• David T. Dicker

  46 shared

• Xianxin Hua

  University of Pennsylvania

  37 shared

• Virginia A. LiVolsi

  Hospital of the University of Pennsylvania

  36 shared

• Cynthia Krankel

  Dana-Farber Cancer Institute

  36 shared

Labs

• Zhaohai Yang LaboratoryPI