The document discusses various types of pancreatic tumors including epithelial tumors, premalignant lesions, malignant lesions, mesenchymal tumors, lymphomas, and secondary tumors of the pancreas. Imaging studies like CT, MRI, US, and ERCP are important for evaluating pancreatic tumors. Tumors are classified based on characteristics like size, location, presence of solid components or cysts, and extent of invasion or metastasis. Surgical resection is not possible if the tumor involves surrounding organs or structures or has spread to distant sites.