Monarch Disease Ontology entry MONDO_0005034 (thyroid gland follicular carcinoma) is a differentiated adenocarcinoma arising from the follicular cells of the thyroid gland. The nuclear features which characterize the thyroid gland papillary carcinoma are absent. Radiation exposure is a risk factor and it comprises approximately 10% to 15% of thyroid cancers. Clinically, it usually presents as a solitary mass in the thyroid gland. It is generally unifocal and thickly encapsulated and shows invasion of the capsule or the vessels. Diagnostic procedures include thyroid ultrasound and fine needle biopsy. Also known as: carcinoma of thyroid follicle, carcinoma, follicular cell, malignant, follicular carcinoma, follicular carcinoma of the thyroid, follicular carcinoma of the thyroid gland, follicular carcinoma of thyroid, follicular carcinoma of thyroid gland, follicular thyroid cancer.