Neuroendocrine Neoplasms of the Lungs, Thyroid, and Thymus.

Neuroendocrine neoplasms (NENs) comprise a group of tumours that can develop in various internal organs, but in this review, we will describe only those arising in the lungs, thyroid, and thymus. Pulmonary neuroendocrine neoplasms (pulmonary NENs) account for approximately 25% of all lung cancers. They are classified into four groups of tumours: typical carcinoids (TCs), atypical carcinoids (ACs), small cell lung carcinoma, and large cell lung carcinoma. This review focuses on TC and AC. The treatment consists mainly of radiotherapy, chemotherapy, and surgical resection, but novel drugs like atezolizumab are also utilised. The most common neuroendocrine neoplasm of the thyroid gland is medullary thyroid carcinoma (MTC), which commonly possesses RET protooncogene mutations. MTC is treated by a total thyroidectomy. Recently, tyrosine kinase inhibitors (TKIs) have emerged as an effective treatment option for patients with advanced MTC. Neuroendocrine tumours of the thymus (NETTs) are also being treated with a radical surgery.