A prospective follow-up study on completion thyroidectomy for well-differentiated thyroid cancer. A single-center report.

BACKGROUND: Completion thyroidectomy (cT) becomes a choice after any type of less than total thyroid surgery, when a "total" would have been indicated on primary intervention if malignancy diagnosis had been available. The study main aim is to define predictive factors of malignancy in the thyroid remnant and to assess the morbidity risk after cT according to the type of initial intervention. MATERIAL AND METHOD: Sixty-three patients on whom cT was performed were finally included with 61 surgeries performed in our department. RESULTS: Or cohort included 55 (87.3%) women and 8 men (12.7%), with a mean age of 48.3 on whom were primary performed 34 lobectomies with isthumusectomies (LwI=53.96%) and 29 subtotal thyroidectomies or hemithyroidectomies (STT=46.03%). Histopathological examination after reintervention detected malignancy in 30.15% of excised thyroid remnants (19 patients), in the majority of these cases microcarcinoma. We found statistically significant correlations between the risk of malignancy in the thyroid remnant and both the primary thyroid tumor multicentricity (p=0,001) and its extracapsular and/or vascular invasion (p=0,006) respectively. The time span between the two interventions ranged from 3 days to 12 months (mean 63 days). No 30-day mortality occurred in our group of patients. We noted 3 cases of RLN palsy (4.76%) of which one permanent (1.58%) and 12 cases (19.04%) of postoperative hypoparathyroidism, of which two (3.17%) permanent. CONCLUSIONS: Multicentricity and capsular and/ or vascular invasion of the initial tumor are factors predictive of malignancy in the remnant thyroid. The rate of postoperative hypoparathyroidism is higher after initial subtotal thyroidectomy. KEY WORDS: Completion thyroidectomy, Incidental parathyroidectomy, Multifocality, Thyroid cancer.