Pathology of upper gastrointestinal malignancies

Area of Science:

• Gastroenterology and Oncology
• Pathology
• Molecular Biology

Background:

• Upper gastrointestinal (GI) tract carcinomas, including esophageal, gastroesophageal junction (GEJ), and gastric cancers, represent a significant global health challenge.
• Understanding their diverse features is crucial for accurate diagnosis, prognosis, and treatment strategies.

Purpose of the Study:

• To provide a comprehensive overview of the macroscopic, histological, and molecular biological characteristics of upper GI tract carcinomas.
• To discuss the main histological subtypes, classifications, precursor lesions, and genetic alterations associated with these cancers.

Main Methods:

• Literature review focusing on macroscopic, histological, and molecular features of upper GI tract cancers.
• Inclusion of established classification systems like Lauren's and the World Health Organization (WHO) classification.
• Discussion of tumor spread, precursor lesions (dysplasias), and somatic genetic/epigenetic changes.

Main Results:

• Detailed description of adenocarcinoma, squamous cell carcinoma, and small cell carcinoma of the esophagus, GEJ, and stomach.
• Explanation of histological classifications and rare variants relevant to upper GI tract adenocarcinomas.
• Outline of tumor spread patterns, classification principles, and precursor lesions such as dysplasia.
• Discussion of key somatic genetic and epigenetic alterations driving upper GI tract tumor development.

Conclusions:

• Accurate characterization of upper GI tract carcinomas requires integrating macroscopic, histological, and molecular data.
• Understanding precursor lesions and genetic alterations is vital for advancing early detection and therapeutic interventions.
• This review consolidates essential information on upper GI tract cancer features for researchers and clinicians.