Frequent synaptophysin expression in SMARCA4-deficient undifferentiated carcinoma of the oesophagus: a diagnostic pitfall with therapeutic implications

Key Points

• Frequent synaptophysin expression leads to potential diagnostic confusion with neuroendocrine carcinomas.
• Incorporating BRG1 IHC improves the diagnostic accuracy for poorly differentiated oesophageal tumours.
• This distinction is crucial for effective treatment strategies and management of the disease.
• Misclassification may result in significant mismanagement of patient care, highlighting a need for proper diagnostics.