Objective To investigate the clinicopathologic features and treatment of thyroid microcarcinoma (TMC). Methods From January 1997 to December 2006,311 patients who underwent surgery and defined as TMC(tumor size≤1 cm)were enrolled. Results TMC was identified incidentally by frozen pathologic examination on thyroidectomy specimens in tentative benign goiters in 181 patients; another 130 patients with clinically detectable primary tumors or suspected nodal metastases were grouped to as clinically overt TMC. The clinically overt TMC had a higher incidence of bilateral multifocal tumors (18.5%vs.9.4%,P=0.03),and cervical lymph node metastases(27.7%vs.10.5%,P=0.000)than that in clinically occult TMC group. Conclusion TMC may vary considerably in clinical and biologic behaviors between these two subtypes: clinically overt and occult. Lobectomy for single lesion, total or near total thyroidectomy for multifocal with central compartment nodal dissection should be performed, lateral nodal dissection was not carried out unless US or physical examination detected nodal metastases. Lobetomy, subtotal or more limited thyroidectomy for occult TMC, diagnosed incidentally following thyroid surgery for initially tentative benign thyroid disease, could all be treatment of choice depending on the preference of surgeons.

Objective:To analyze the monitoring results of iodine deficiency disorders (IDD) in Hainan Province from 2011 to 2023, key prevention and control measures taken during this period, and the impact of related events on the monitoring results.Methods:From 2011 to 2023, a systematic sampling method was used to divide 21 cities (districts, counties) in Hainan Province into 5 districts based on east, west, south, north, and center each year. One township (street) was selected from each district, and 40 children aged 8 - 10 (non boarding students) and 20 pregnant women were selected from each township (street) for determination of iodine level of their household salt and urine samples. Based on the monitoring results, the impact of key events such as the pre reduction (2011), post reduction (implementation of new iodized salt standard, 2012 - 2023), salt industry system reform (2017), and the two-year campaign for endemic disease prevention and control (2019, 2000), on the salt iodine coverage rate and qualified iodized salt consumption rate, the urinary iodine level and its distribution in children and pregnant women were analyzed in Hainan Province. B-ultrasound was used to detect the situation of thyroid enlargement was analyzed.Results:(1) In 2011, the median iodine level in edible salt of residents in Hainan Province was 32.1 mg/kg. It was 30.8 mg/kg after the implementation of the new standard in 2012. In 2013, the salt iodine level of residents had significantly decreased to 25.9 mg/kg, with 24.5, 24.2, and 23.8 mg/kg in 2017, 2019, and 2020, respectively. The differences of median salt iodine levels between different years were statistically significant ( H = 29.01, P < 0.001). The coverage rate of iodized salt among residents in Hainan Province from 2011 to 2023 was 98.08% (80 727/82 308), and the difference between different years was statistically significant (χ 2 = 9.51, P = 0.023). The consumption rate of qualified iodized salt was 95.65% (78 738/82 308), and the difference between different years was statistically significant (χ 2 = 21.80, P < 0.001). (2) The median urinary iodine level of children from 2011 to 2023 was 177.5 μg/L, with a median of 204.2 μg/L in 2011. After the implementation of the new standard, the median urinary iodine level of children was 194.9 μg/L in 2012. In 2013, the median urinary iodine level in children decreased to 167.8 μg/L, and had remained within the range of 100 - < 200 μg/L thereafter. In 2017, 2019, and 2020, the median urinary iodine levels were 170.4, 172.8, and 186.3 μg/L, respectively. There was no statistically significant difference in different years ( H = 1.67, P = 0.061). The proportion of children with urinary iodine < 100 μg/L from 2011 to 2023 was 16.29% (8 740/53 634), and the proportion of children with urinary iodine between 100 and < 200 μg/L was 43.96% (23 575/53 634). The differences between different years were statistically significant (χ 2 = 21.50, 23.40, P < 0.001). The childhood goiter rate from 2011 to 2023 was 0.19% (101/53 634). (3) The median urinary iodine level of pregnant women was 153 μg/L in 2011, it was 154.7 μg/L in 2012 after the implementation of the new standard, and it had remained within the range of 100 - < 150 μg/L since then. The median urinary iodine level of pregnant women was 126.2 μg/L in 2013. The median urinary iodine level in 2017, 2019 and 2020 were 123.5, 133.8, and 135.4 μg/L, respectively. There was a statistically significant difference in the median urinary iodine levels of pregnant women between different years ( H = 92.10, P < 0.001). From 2011 to 2023, the proportion of pregnant women with a median urinary iodine level < 150 μg/L was the highest (55.75%, 14 761/26 477). Conclusion:From 2011 to 2023, although the monitoring results of iodine deficiency disorders in children and pregnant women in Hainan Province have fluctuated, they are still in a state of continuous elimination of IDD.

Objective:To understand the iodine nutritional status of key population and its correlation with water iodine and salt iodine in Hainan Province, and to provide scientific basis for iodine supplement.Methods:According to the "National Water Iodine Content Survey Program for Drinking Water" and the "National Iodine Deficiency Disorders Surveillance Program (2016)", surveys on water iodine and iodine nutritional status of key populations in 21 cities (counties, districts) in Hainan Province in 2017 and 2018 were conducted. Water samples, urine samples at random and home salt samples of children aged 8 - 10 years old and pregnant women were collected to detect water iodine, urinary iodine and salt iodine. At the same time, the thyroid volume of children was measured by B-mode ultrasound, and the goiter rate was calculated. According to the geographical location, Hainan Province was divided into 3 areas: central mountainous, western coastal and eastern coastal, the results of water iodine, salt iodine and urinary iodine in different areas were compared and analyzed. Water iodine was detected by "Water Iodine Detection Method Suitable for Iodine Deficiency and High Iodine Areas" recommended by National Reference Laboratory for Iodine Deficiency Disorders; urinary iodine was detected by arsenic cerium catalytic spectrophotometry; salt iodine was detected by direct titration.Results:A total of 2 566 water samples were detected, and the median water iodine was 6.0 μg/L. A total of 4 220 urine samples of children were detected, the median urinary iodine was 170.0 μg/L (appropriate range was 100 - 199 μg/L), the goiter rate was 0.09% (4/4 220). A total of 2 124 urine samples of pregnant women were detected, the median urinary iodine was 120.7 μg/L (appropriate range was 150 - 249 μg/L). A total of 6 344 salt samples were detected, coverage rate of iodized salt, qualified rate of iodized salt and consumption rate of qualified iodized salt were 97.76% (6 202/6 344), 97.47% (6 045/6 202), and 95.29% (6 045/6 344), respectively. In central mountainous, western coastal and eastern coastal areas, medians water iodine were 3.3, 6.5, and 6.5 μg/L, respectively, the difference was statistically significant ( H = 13.721, P < 0.01); the consumption rates of qualified iodized salt were 97.86% (1 833/1 873), 90.52% (1 613/1 782), and 96.65% (2 599/2 689), respectively, the difference was statistically significant (χ 2 = 71.217, P < 0.01); the medians urinary iodine of children were 182.4, 160.1, and 167.4 μg/L, respectively; the medians urinary iodine of pregnant women were 120.1, 117.7, and 103.9 μg/L, respectively. There was a positive correlation between urinary iodine in children and pregnant women and salt iodine ( r = 0.394, 0.657, P < 0.05). Conclusions:The iodine nutrition of children in Hainan Province is generally at an appropriate level, and pregnant women are at risk of iodine deficiency. There is a positive correlation between urinary iodine in children and pregnant women and salt iodine. The prevention and treatment of iodine deficiency disorders should focus on strengthening iodine nutrition monitoring of pregnant women.

Objective To grasp the distribution of iodine in drinking water in the environment of Hainan Province,and provide scientific basis for prevention and treatment of iodine deficiency disorders.Methods In 2017,in all cities (counties,districts) in Hainan Province,townships were used as units to collect water samples to detect iodine content according to their different water supply methods.In the townships with median drinking water iodine ＞ 10 μg/L,the administrative village (neighborhood committee) was used as a unit to collect water sample to detect iodine content.According to the geographical location (central mountainous area,eastern coast,western coast),water source type (tap water,intubation well,spring water),and well depth,the distribution of water iodine was analyzed.Results A total of 2 566 water samples were detected in 21 cities (counties,districts),the median water iodine was 6.0 μg/L,range was 0.1-150.6 μg/L,the median water iodine of all cities (counties,districts) was ＜ 10 μg/L.The median water iodine in the central mountainous area,eastern coast,and western coast were 3.3,6.5,6.5 μg/L,respectively;tap water,intubation well,and spring water were 5.6,6.4,1.3 μg/L,respectively;0-,100-,200-,≥300 m well depth were 6.6,5.1,4.2,and 1.5 μg/L,respectively.The water iodine content range was 0.2-17.9 μg/L in 230 townships in the province,there were 12 townships with the median water iodine ＞ 10 μg/L,including 133 administrative villages (neighborhood committees),and 737 water samples were detected,the water iodine content range was 1.0-37.1 μg/L.Conclusions All cities (counties,districts) in Hainan Province belong to iodine deficiency areas,the central mountainous area is even more serious.Most of the townships in the province are in iodine deficiency.No administrative villages (neighborhood committeea) with high iodine have been found.The province should continue to implement salt iodization to prevent and treat iodine deficiency disorders.