Medullary carcinoma is a type of cancer that usually develops in the thyroid gland in the neck. Rare forms of the cancer can appear in breast, brain, lung, and lymph node tissue as well. As a tumor grows, it produces one or more palpable nodules that can cause airway constriction, coughing, fatigue, and other uncomfortable symptoms. Treatment for medullary carcinoma usually involves a combination of surgery, radiation, and medications. Patients generally have a good prognosis when their tumors are discovered and treated early, but advanced stages of the cancer have a high mortality rate.
Doctors do not fully understand what causes medullary carcinoma. Some patients have familial histories of thyroid disorders and cancers, but many cases are seemingly sporadic. Ongoing medical evidence suggests that receiving radiation therapy for other types of cancer in the head or neck may increase the risk of developing medullary carcinoma. A person can develop the cancer at any age, but adults over the age of 50 are at the greatest risk.
Most medullary carcinoma tumors develop from abnormal C cells in the thyroid gland. C cells are important hormone producing and releasing cells. Among other functions, they supply the body with calcitonin to regulate calcium levels in blood and bones. When a group of C cells become malignant, they begin to replicate uncontrollably and grow into a tumor. Calcitonin production can become significantly impaired or greatly increased, and either consequence can lead to irreparable damage to bones and organs.
The most common symptoms of a growing thyroid tumor include difficulty swallowing and breathing, hoarseness, and a soft lump at the base of the neck. Many patients experience fatigue, muscle weakness, and weight loss as well. A medullary carcinoma elsewhere in the body can cause lymph node swelling, breast tenderness, or chronic headaches. It is important to visit a doctor at the first signs of a neck lump or other symptoms to receive an accurate diagnosis.
A physician diagnoses medullary carcinoma by physically inspecting lumps, performing blood tests, and ordering imaging scans. Blood tests may reveal unusual calcitonin levels, and computerized tomography scans can detect abnormalities on the thyroid. An oncology surgeon might need to extract a piece of thyroid tissue to confirm the presence of cancer.
Once a diagnosis has been made, a team of specialists determines the best way to initiate treatment. When a tumor is found early and the cancer has not yet spread to other parts of the body, surgery to remove part or all of the thyroid may be effective. Radiation treatments are usually needed if cancer spreads or surgery is unsuccessful at excising the entire tumor. Patients also typically receive pain medications and hormone replacement drugs throughout their treatment to ease symptoms.