Mixed acinar-endocrine carcinoma of the pancreas

Mixed acinar-(neuro)endocrine carcinoma (MAEC) is a malignant epithelial neoplasm of the pancreas exhibiting both acinar and (neuro)endocrine differentiation and is diagnosed when each component constitutes a significant proportion (25%-30%) of the neoplasm. Histologically, many are similar to acinar cell carcinoma (ACC), with the mixed differentiation detected by immunohistochemistry and share many clinicopathological features with ACC. Therefore, MAEC has been considered a variant of ACC. This review addresses the pathology, clinical features, and histogenesis of MAEC and its differential diagnosis.