This document summarizes different types of thyroid neoplasms including benign and malignant tumors. It discusses the pathology, clinical features, investigations and treatment for various thyroid cancers such as papillary carcinoma, follicular carcinoma, medullary carcinoma, and anaplastic carcinoma. Risk stratification for differentiated thyroid cancers is also mentioned. Hypothyroidism and its causes, types and treatment are briefly covered at the end.