Prediction of hypothyroidism after hemithyroidectomy: a biochemical and pathological analysis

Abstract

The possibility of postsurgical hypothyroidism after hemithyroidectomy is no longer a new subject. Although many previous studies have mentioned posthemithyroidectomy hypothyroidism, the incidence and contributing factors for hypothyroidism remain uncertain. We intended to evaluate the incidence and the time of development of hypothyroidism after hemithyroidectomy and to analyze the relationship of posthemithyroidectomy hypothyroidism with preoperative biochemical parameters and postoperative histopathological findings. From February 2001 through December 2004, 287 consecutive cases of hemithyroidectomized patients were retrospectively analyzed; 136 of these patients were included in this study after the exclusion criteria were applied. The relationship between posthemithyroidectomy hypothyroidism and several parameters such as sex, age, preoperative free T4, TSH, microsomal antibody (Ab), thyroglobulin antibody (Ab) levels and lymphocytic infiltration of the resected gland was statistically analyzed. Postoperative hypothyroidism developed in 58 patients (42.6%). In hypothyroid group, 11 patients (19%) showed overt hypothyroidism and 47 patients (81%) showed subclinical hypothyroidism. Preoperative TSH value was significantly higher in the hypothyroid group (2.15+/-1.30 microU/ml) compared to the euthyroid group (1.29+/-0.9 microU/ml). Positive ratio of preoperative microsomal Ab and thyroglobulin Ab were significantly higher in hypothyroid group (38.9 and 41.9%) compared to euthyroid group (3.6 and 19.3%) (P <0.05). In addition, patients with a higher grade of lymphocytic infiltration were found to have a higher probability of developing hypothyroidism. About 85% of postoperative hypothyroidism was detected between 1 and 6 months postoperatively. We might predict the possibility of developing the posthemithyroidectomy hypothyroidism especially in case of preoperatively positive microsomal antibody, thyroglobulin antibody and high-grade lymphocytic infiltration of the resected gland. In addition, our findings support the recommendation for regular serum TSH follow-up at least for 12 months after hemithyroidectomy.

Evolution in the profile of thyroid cancer cases treated in an oncology reference service: what changed in the last 20 years

“…In all cases with a preoperative diagnosis of carcinoma, the recommended treatment is total thyroidectomy 11,18,19 . This trend is driven by the more frequent recognition of postpartial thyroidectomy hypothyroidism, both in our experience (not yet published) and in several other analyzes 19,[23][24][25][26][27] and also by the advantage of enabling the adjuvant radioiodine therapy when indicated, and the more accurate use of serum thyroglobulin and whole body scan with I 131 during postoperative follow-up, without increased risk of complications 28 . The treatment of nodular thyroid disease in our Department routinely involves intraoperative frozen biopsy.…”

Hypothyroidism After Hemithyroidectomy: Incidence, Risk Factors, Natural History and Management

“…The degree of lymphocytic infiltration, graded on a scale of 0-IV, into the resected thyroid lobe may aid in predicting the development of hypothyroidism in post-hemithyroidectomy patients (Koh et al, 2008). An extensive review of histopathologic data, which assessed whether the degree of lymphocytic infiltration and germinal center formation within the thyroid lobe could accurately predict the development of postoperative hypothyroidism, found that when inflammation was graded based on the extent of lymphocytic infiltration (graded 0-3) and the frequency of germinal centers was qualitatively assessed as a histologic measure of immunologic activation (graded 0-3), most patients with lymphocytic infiltration or germinal center formation in the resected thyroid lobe are at increased risk for posthemithyroidectomy hypothyroidism (Johner et al, 2011).…”

“…If the TSH level is normal at 12 months, biannual to annual determination of TSH levels was encouraged unless symptoms of hypothyroidism manifest. Koh, et al (2008) If preoperative risk factors (presence of microsomal Ab and thyroglobulin Ab, or higher degree of lymphocytic infiltration of resected thyroid gland) were present, these patients were to be follow up at least for 12 months with explanation of possibility of developing postsurgical hypothyroidism.…”

Clinical Features of Early and Late Postoperative Hypothyroidism After Lobectomy

“…Critically, studies investigating risk factors for this postlobectomy complication are not in agreement because of varying follow-up durations, hypothyroidism definitions, thyroid-function assessment timings, and thyroid-hormone-supplementation criteria between the studies (1,(7)(8)(9)(10). Most studies reported that postoperative hypothyroidism developed within the first postoperative year in 90% of patients; however, median follow-up periods in previous studies were relatively short, generally being ,24 months (7,8,(10)(11)(12), which may have underestimated the incidence of postoperative hypothyroidism.…”