A RATIONALE FOR CONSERVATIVE MANAGEMENT OF MICROSCOPIC PAPILLARY CARCINOMA OF THE THYROID-GLAND - A CLINICOPATHOLOGICAL CORRELATION OF 90 CASES

Microscopic papillary carcinoma of the thyroid gland (MPC) measuring l ess than or equal to 1.0 cm in diameter has a generally benign outcome , but is often overtreated with additional surgery. Ninety cases of MP C and 77 cases of non-microscopic papillary carcinoma of the thyroid g land (non-MPC) from 1970 to 1980 were retrieved from the Endocrine Reg istry of the Armed Forces Institute of Pathology (AFIP), Washington, D .C. Histologic features and patient follow-up were analyzed. Twenty-on e patients with MPC had multifocal disease within the affected thyroid lobe, while a further 15 had either bilateral or intraglandular sprea d. Four of 10 patients who bad additional surgery were found to have a dditional foci of tumor. Fourteen patients with lymph node metastases at initial surgery had no subsequent nodal metastases. All patients we re either alive without disease or had died of unrelated causes after an average follow-up period of 17.3 years. Of the 77 non-MPC patients, 13 developed lymph node metastases or local recurrences, and one died of metastatic disease. Sixty-four of these patients were alive withou t evidence of disease after an average follow-up of 22 years. Present findings show that while MPC may present with perithyroidal lymph node metastases (15.56%), patients do not develop clinical tumors in the r emaining thyroid tissue. Our experience indicates that close clinical followup without additional surgery is the preferable management for p atients with MPC.