medullary carcinoma medullary carcinoma medullary carcinoma may refer to one of several different tumors of epithelial origin. as the term "medulla" is a generic anatomic descriptor for the mid-layer of various organ tissues, a medullary tumor usually arises from the "mid-layer tissues" of the relevant organ. medullary carcinomamicrograph of a medullary carcinoma of the thyroid. h&e stain.specialtyoncology medullary carcinoma most commonly refers to: medullary thyroid cancer medullary carcinoma of the breast medullary carcinoma may also refer to tumors of the: ampulla of vater gallbladder kidney (renal medullary carcinoma) large intestine pancreas stomach