thyroid cancer

Discussion in 'MRCS Forum' started by Javed., Feb 5, 2008.

  1. Javed.

    Javed. Guest

    Q. A 62-year-old Polynesian woman, who grew up in the South Pacific in the 1650s, has a lump in her neck. Which statement concerning radiation induced thyroid cancer is true?

    a- It usually follows high-dose radiation to the head and neck
    b- A patient with a history of radiation is safe if no cancer has been found 20 years after exposure
    c- Approximately 25% of patients with a history of head and neck irradiation develop thyroid cancer
    d- Most radiation-induced thyroid cancers are follicular
    e- The treatment of choice is a near-total (or total) thyroidectomy
  2. Javed.

    Javed. Guest

    Answer: e. (Greenfield, 2/e, pp 1301-1303) Radiation-induced thyroid cancer was first recognized in 1950 by Duffy and Fitzgerald. It usually follows low-dose external radiation. Most cancers occur after exposure to 1500 rads or less to the neck, but an increase in thyroid cancer has been noted after as little as 6 rads. Salivary gland tumors and possibly parathyroid adenomas are also associated with radiation. The latent period for these tumors is 30 years or longer. Of all patients exposed to low-dose radiation, about 9% have been found to have thyroid cancer, usually of the papillary type. Treatment consists of a near-total thyroidectomy because incidence of complications if a second operation is necessary.

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