Patients with thyroid microcarcinoma have usually excellent prognosis. However, recurrences in neck and distant metastases have been reported. The optimal treatment for this group of patients is still discussed. The aim of study was to present the clinical and histopathological data of our group of patients with differentiated thyroid carcinoma of 1 cm or less in size diagnosed from 1990 to 2000. 146 patients (137 females and 9 males, mean age 47 years) with differentiated thyroid carcinoma up to 1 cm in the greatest dimension were analyzed. The median follow-up time was 3.5 years. The diagnosis was incidental (made after primary surgery) in 82% of cases. In 85% of patients papillary thyroid carcinoma was diagnosed (in 6% of them as follicular variant). Histopathological risk factors were noticed in 32 patients (21%). The patients were operated in different surgical clinics in Poland. 5% (8) of primary operations and 51% (33) of secondary ones were performed in our center. The most frequent primary operation was bilateral, subtotal strumectomy (62%). Total thyroidectomy was made in 14% of cases (21). Secondary radical operation was performed in 65 patients (44%). Residual cancer was found in 9% of reoperated patients. 47% of patients (69) were treated with 131I and all of them were administered hormonal therapy to suppress TSH. No recurrence and distant metastases were observed. Lymph node metastases were diagnosed and treated in 10 patients (7%). During observation period 1 patient died because of breast cancer. No statistically significant influence of clinical and histopathological risk factors or operation type on clinical outcome was observed. In the analyzed group secondary surgery was connected with the higher risk of complications.
Conclusions: In thyroid papillary microcarcinoma total thyroidectomy is recommended for patients with multiple foci of neoplasm or with metastases (lymph node or distant). Establishment of optimal treatment in minimal follicular thyroid cancer is not possible on the basis of our data and published literature.