Secondary malignancy of the thyroid gland and its management

Secondary cancer of the thyroid gland is widely acknowledged as infrequent but is a persistent problem requiring ongoing awareness, particularly with respect to clinical recognition and treatment. From 1978 to 1993, a 15-year period, patients demonstrating secondary involvement of the thyroid gland as a surgical problem were collected and analyzed with regard to pathology, demography, behavior of primary and secondary disease, treatment, and patient outcome. In the 15-year span, 11 patients with secondary involvement of the thyroid gland were recognized, consisting of 3 men and 8 women with primary lesions occurring in oral cavity, esophagus, stomach, colon, pancreas, breast, skin, unknown, kidney, and lung. Needle biopsy produced a 90% malignancy rate but in only half of such cases was the diagnosis specific for secondary malignancy. Eight of 11 underwent palliative surgery, usually total thyroidectomy. No patient survived > 2 years. There was no undue surgical morbidity. One patient died of pulmonary embolus postoperatively. Secondary cancer of the thyroid is rare and can be detected by fine-needle aspiration biopsy in the face of clinical findings. Where indicated, palliative thyroidectomy can be effective, because other methods of treatment appear ineffective.