Supplementary Material for: Rare Primary Hepatic Mucoepidermoid Carcinoma: Report of Two Cases

Introduction: Primary mucoepidermoid carcinoma ( MEC ) of the liver is an extremely rare malignant tumor with nonspecific symptoms and signs. Case Presentation: The two cases included one Chinese male and one Chinese female, aged 72 and 47 years, respectively. Their clinical manifestations were hematemesis and upper abdominal pain. Imaging features were atypical, showing heterogeneous enhancement or cystic areas. After surgical resection, the pathological diagnosis was hepatic mucoepidermoid carcinoma, and CRTC1-MAML2 fusion gene was found. Both patients did not undergo radiotherapy and chemotherapy after operation, and died of tumor metastasis 3-4 months after tumor resection. Conclusion: Hepatic MEC is rare and has an extremely poor prognosis. Surgical resection is the main treatment, and diagnosis requires confirmation through histopathology, immunohistochemistry, and special staining. CRTC1-MAML2 fusion can also assist diagnosis.