What is the primary organ affected by linitis plastica?

Linitis Plastica Originates in the Stomach

Linitis plastica is a diffuse-type gastric adenocarcinoma that originates in the stomach, characterized by infiltration of cancer cells throughout the gastric wall, resulting in thickening and rigidity of the stomach. 1

Pathological Characteristics

• Linitis plastica is predominantly a diffuse-type gastric adenocarcinoma according to the Lauren classification 1
• Key histopathological features include:
  • Poorly differentiated cells with discohesive pattern infiltrating the gastric wall 1
  • Often presents with signet-ring cell morphology 1
  • Extensive desmoplastic (fibrotic) reaction in the gastric wall 2, 3
  • Classified as Borrmann Type IV in the advanced gastric cancer classification system 1

Clinical Presentation

• Often presents late due to lack of early symptoms 4
• Classic appearance includes:
  • Thickening and rigidity of the stomach wall 4, 5
  • "Leather bottle-like" appearance of the stomach 5
  • Reduced gastric distension and deformation 5
  • Characteristic "waffle-like" appearance of gastric folds on endoscopy 5

Diagnostic Approach

• Comprehensive imaging is essential for diagnosis:
  • CT scan can detect tissue fibrosis in the gastric wall, even in relatively small lesions 2
  • Endoscopic ultrasound (EUS) shows diffuse submucosal thickening of the gastric wall 6
  • EUS-guided fine-needle aspiration or bite-on-bite biopsy is recommended when standard biopsies are negative 1, 6

Genetic Associations

• Strong association with germline truncating mutations in the CDH1 gene in hereditary diffuse gastric cancer (HDGC) 1
• First-degree relatives of individuals with diffuse gastric cancer have significantly increased risk 1
• Carriers of MSH2 and MSH6 mutations (Lynch syndrome) have increased risk of developing this type of gastric cancer 1

Prognosis and Management

• Generally poor prognosis due to late diagnosis and aggressive nature 1, 4
• Most patients are offered palliative or supportive treatment due to advanced disease at diagnosis 1, 4
• Multimodal approach with combined treatment offers the best outcomes for eligible patients 1
• Assessment of HER2 status is recommended as HER2-positive tumors may benefit from targeted therapy 1

Important Clinical Considerations

• The diffuse infiltrative nature makes early detection challenging
• Cancer-stroma interactions are important features of this disease and represent potential targets for future therapies 3
• Genetic counseling and testing should be considered for individuals with family history of diffuse gastric cancer 1

Understanding that linitis plastica originates in the stomach is crucial for proper diagnosis, staging, and treatment planning, as this aggressive form of gastric cancer has unique biological behavior that impacts clinical management.