Experimental Factor Ontology entry EFO_1001436 (thyroid nodule) is a small circumscribed mass in the THYROID GLAND that can be of neoplastic growth or non-neoplastic abnormality. It lacks a well-defined capsule or glandular architecture. Thyroid nodules are often benign but can be malignant. The growth of nodules can lead to a multinodular goiter (GOITER, NODULAR). Also known as: Nodule of the Thyroid gland, Thyroid Nodule, Thyroid nodule, Thyroid nodule (disorder).