PTEN and pancreatic neuroendocrine tumor: While the existing solid tumor panel used could not identify possible driver mutations for development of strumal carcinoids, known driver mutations of neuroendocrine tumors (e.g., PTEN mutations in pancreatic neuroendocrine tumors or genes of the mTOR signaling pathway in neuroendocrine tumors of the small intestine and the lung [25]) were not detected in this series.