|Year : 2017 | Volume
| Issue : 1 | Page : 25-27
Histologic pattern of thyroid disorders in Southern Kerala
Jayasree Geothe1, KP Poulose2
1 Department of Pathology, Sree Mookambika Institute of Medical Sciences, Kulasekharam, Kanyakumari, Tamil Nadu, India
2 Department of Medicine, S.U.T. Hospital, Pattom, Trivandrum, Kerala, India
|Date of Web Publication||20-Feb-2017|
Department of Pathology, House No 11 B, Pattom Square Apartments, Trivandrum - 695 004, Kerala
Source of Support: None, Conflict of Interest: None
Since the implementation of universal salt iodization in 1986, India is said to be in the transition phase from iodine deficiency to iodine sufficiency, and this is expected to change the spectrum of thyroid disorders in the country. Materials and Methods: A retrospective study of 246 biopsy specimens of subtotal/total/hemi thyroidectomy cases done during a period of 6 years from 2007 to 2012 at a tertiary hospital in Trivandrum, Kerala, is analyzed. Results: Thyroidectomy specimens accounted for 3.2% of the total surgical specimens received during the study period. Among the 246 thyroidectomy specimens, nodular colloid goiter (NCG) with or without other associated thyroid lesions outnumbered other disorders accounting for a total of 142 cases (58%) followed by 90 cases of autoimmune thyroiditis (AIT) with or without other thyroid lesions (37%). Dual lesions such as AIT with colloid goiter (7 cases, 3%), AIT with tumors (45 cases, 18%), and NCG with tumors (40 cases 16%) were also noted. The presence of tumors was found in 106 cases (43%). The overall incidence of malignancy was 36%. Forty-one cases of AIT and 36 cases of NCG were associated with papillary thyroid carcinoma (PTC) (46% and 25%, respectively); the difference was statistically significant (P = 0.01). Conclusions: This study showed that the incidence of AIT and associated PTC is high, and the role of iodine or any other goitrogens in triggering or enhancing the onset and development of AIT in this area deserves further study.
Keywords: Thyroid disorders in Kerala, thyroiditis in Kerala, thyroid tumors in Kerala
|How to cite this article:|
Geothe J, Poulose K P. Histologic pattern of thyroid disorders in Southern Kerala. Thyroid Res Pract 2017;14:25-7
| Introduction|| |
Since the implementation of universal salt iodization in 1986, results of many recent studies done in various parts of India have shown that iodine status of the population has become adequate though pockets of iodine deficiency still exist. In a population-based study done in Cochin, Kerala, the Urinary Iodine Status was studied in 954 subjects; it was found that median urine iodine excretion was 211.4 mcg/L (mean 220.3 ± 99.5 mcg/L) and suggested that this population was iodine sufficient, whereas in the state of Gujarat iodine deficiency continues to be a problem as more than 20% of the population had a very low median urinary iodine of <50 mcg/L. Hence, India is said to be in the transition phase from iodine deficiency to iodine sufficiency, and this is expected to change the spectrum of thyroid disorders of the population. The aim of this study is to find out whether any change in the disease pattern of thyroid diseases in the Southern region of Kerala, in this postiodization phase by analysis of thyroid specimens received in the Histopathology Department.
| Materials and Methods|| |
In this retrospective study, 246 biopsy reports of subtotal/total/hemi thyroidectomy cases done during a period of 2007–2012 at S.U.T. Hospital, Pattom, Trivandrum, were analyzed. All thyroid specimens irrespective of age, gender, race, and demographic habitat were included in the study. Diagnoses were made after careful gross examination of thyroidectomy specimen and analysis of representative microscopic sections. The results were analyzed and compared with available data.
The data were analyzed by SPSS (16.0 version, SPSS Inc. 2007, Chicago.) software. The significances were calculated by Chi-square and Fisher's exact tests. P < 0.05 was considered statistically significant.
| Results|| |
Thyroidectomy specimens accounted for 3.2% of the total surgical specimens (246 out of 7579 cases) received during the study period. Of the 246 cases of thyroidectomy specimens studied, 213 were females and 33 were males with a male:female ratio of 1:6.5. Around 140 (57%) lesions were nonneoplastic and 106 (43%) were neoplastic [Table 1]. Nodular colloid goiter (NCG) outnumbered other disorders, accounting for a total of 142 cases (58%) followed by 90 cases (37%) of autoimmune thyroiditis (AIT) (both lymphocytic thyroiditis and Hashimoto's thyroiditis). Dual lesions as NCG with AIT/NCG with tumors/AIT with tumors were also noted. The most common tumor seen with NCG was papillary thyroid carcinoma (PTC) with an incidence of 25.4%. Out of 90 cases of AIT, 45.5% were associated with PTC or with follicular adenoma. The presence of tumors was found in 102 cases of thyroidectomies, and overall malignancy in the whole group was 36% which are summarized in [Figure 1]. Eighty-six out of 102 (84%) thyroid tumors were PTC, the demographic data of which are summarized in [Table 2]. Forty-one cases of AIT and 36 cases of NCG (46% and 25%, respectively) were associated with PTC; the difference was statistically significant [Table 3]. Another interesting finding was the high incidence of micro-PTC with tumor size of <1 cm in greater dimensions as 37/86 cases (43%). Ten cases (12%) of PTC were multicentric type.
|Table 1: Prevalence of distribution of patients according to the type of lesions|
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|Figure 1: Distribution of patients according to the type of tumors of thyroid (P < 0.05 significant compared papillary tumor with others)|
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|Table 2: Distribution of patients with papillary carcinoma according to gender and age|
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| Discussion|| |
Epidemiological data in benign lesions of thyroid collected from the Thyroid Clinic, S.U.T. Hospital, Trivandrum (2010), showed a high incidence of AIT [Table 4]. A recent population survey shows that Central Kerala has a high incidence of thyroid disease varying from 53% in Ernakulam and 37% in Cherthala town, respectively. The analysis of spectrum of thyroid disorders and its relationship to autoimmunity and iodine status of adult population in Central Kerala has been shown that about 98.4% of the population was using iodized salt in the region and still 12% of adults have a palpable goiter, suggesting possible presence of unidentified goitrogens/environmental factors. The higher prevalence of hypothyroidism in South Indian women with metabolic syndrome is also reported, which predisposes them to cardiovascular events. Incidence of AIT and malignant tumors were also much higher in our study compared to a similar study reported previously from South India. Recent increase in incidence of AIT in our region [Table 4] also supports the conclusion of the study that AIT is probably more common than iodine deficiency as a cause of goiter in areas that are now iodine sufficient. We also observed an increasing trend in the prevalence of PTC and AIT similar to that observed by others. Incidence of micro-PTC (12%) in our survey is quite worrisome. This is in contrast to the incidence of occult papillary carcinoma reported previously in our region as 8.6%. Our finding is also consistent with the others that iodine supplementation has shifted the thyroid cancers incidence toward papillary cancers. Similarly, iodine sufficiency may increase the prevalence of thyroid autoantibodies resulting in AIT. A statistically significant correlation of hypothyroidism with antibody positivity in pregnant patients (5% vs. 0.5% in patients with and without antibodies) has been detected in a study from our center. Transplacental transfer of thyroid autoantibodies from mother to fetus is also has been reported. Periodic follow-up with fine needle aspiration cytology is advised in patients with thyroid nodules. It has also been shown that 8.6% developed PTC, 4% developed follicular carcinoma 1.2% developed lymphoma in patients diagnosed to have benign nodules by fine needle aspiration, over a median follow-up time of 4.3 years. Improved public awareness and understanding of thyroid disorders is essential among patients and their families. Influence of excess iodine intake or role of any other environmental factors in this region needs further exploration.
|Table 4: Prevalence of benign thyroid diseases in the Thyroid clinic, SUT Hospital, South Kerala Trivandrum|
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| Conclusion|| |
This study showed that incidence of AIT and PTC has considerably increased, and the role of iodine or any other goitrogens in triggering or enhancing the onset and development of AIT in this area deserves further study.
I take this opportunity to thank Mr. Sarath Babu K., Assistant Professor, Department of Pharmacology, Sree Mookambika Institute of Medical Sciences, Kulasekharam, Kanyakumari (Dist.), Tamil Nadu, for technical support.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]