Medullary carcinoma is a malignant tumor that most commonly refers to medullary thyroid carcinoma, a cancer arising from the parafollicular C cells of the thyroid gland. These cells produce calcitonin, and elevated blood calcitonin levels can be a marker for this disease. On thyroid ultrasound, medullary carcinoma typically appears as a solid, hypoechoic nodule that may contain calcifications. It accounts for about 3 to 5 percent of all thyroid cancers and can occur sporadically or as part of inherited genetic syndromes (MEN 2A and 2B). Medullary carcinoma can also occur in the breast, where it appears as a well-circumscribed mass that may mimic a benign lesion on imaging.
Sonography Term