Neoplastic and Non-Neoplastic Thyroid Lesions in Surgical Material: Historical Review of Five Decades in São Paulo, Brazil

Neoplastic and Non-neoplastic Thyroid Lesions in Autopsy Material: Historical Review of Six Decades in São Paulo, Brazil

Aims and background

The aim of the study was to report and discuss a historical series of neoplastic and non-neoplastic lesions of the thyroid gland obtained at autopsy that were examined between 1931 and 1989 at the Pathology Department of the Medical School of the University of SaTo Paulo.

Methods

Records of 145,043 cases were reviewed to select those affecting the thyroid gland. The slides of these selected cases were analyzed and classified according to the current terminology.

Results

Non-neoplastic lesions comprised 91.62% of the cases (n=4647), and most of them were adenomatous goiter (n=3014). Neoplastic lesions were divided into two groups: primary and metastatic. Of the 282 primary tumors, 135 were benign and 147 were malignant. Among the malignant neoplasms, the most frequent types were follicular, papillary and undifferentiated (n=39, 36 and 29, respectively). The most frequent tumor types among the metastatic neoplasms were lymphoproliferative processes and carcinomas (n=67 and 34, respectively).

Conclusions

We conclude that, because of the high frequency of neoplastic lesions (8.38%), 68.24% of which were malignant, detailed examination of the thyroid by pathological methods should be carefully and systematically performed for the accurate detection of thyroid lesions, especially carcinomas.

Prevalence of thyroiditis and immunohistochemistry study searching for a morphologic consensus in morphology of autoimmune thyroiditis in a 4613 autopsies series

We sought to verify the prevalence of lymphocytic thyroiditis (LT) and Hashimoto's thyroiditis (HT) in autopsy materials. Cases examined between 2003 and 2007 at the Department of Pathology of Faculty of Medicine of São Paulo University were studied. Immunohistochemical analyses were conducted in selected cases to characterize the type of infiltrating mononuclear cells; in addition, we evaluated the frequency of apoptosis by TUNEL assay technique and caspase-3 immunostaining. Significant increase in overall thyroiditis frequency was observed in the present series when compared with the previous report (2.2978% vs. 0.0392%). Thyroiditis was more prevalent among older people. Selected cases of LT and HT (40 cases each) had their infiltrating lymphocytes characterized by immunohistochemical analyses. Both LT and HT showed similar immunostaining patterns for CD4, CD8, CD68, thus supporting a common pathophysiology mechanism and indicating that LT and HT should be considered different presentations of a same condition, that is, autoimmune thyroiditis. Moreover, apoptosis markers strongly evidenced that apoptosis was present in all studied cases. Our results demonstrated an impressive increase in the prevalence of thyroiditis during recent years and our data support that the terminology of autoimmune thyroiditis should be used to designate both LT and HT. This classification would facilitate comparison of prevalence data from different series and studies.

Prognostic influence of clinical and pathological factors in medullary thyroid carcinoma: a study of 53 cases

OBJECTIVES AND INTRODUCTION: Medullary thyroid carcinoma, a neoplasia of intermediate prognosis and differentiation, does not always respond predictably to known treatments. This study aimed to correlate the clinical progression of surgically treated patients with clinical and pathological data.

METHODS

A total of 53 patients were followed for 75 months (mean average) in tertiary-care hospital. The clinical status of patients at the end of the study period was characterized to determine correlations with a range of disease aspects. A value of p < 0.05 was considered statistically significant.

RESULTS

Twenty-two patients (41.5%) were alive and disease-free at the end of the follow-up period; twenty-three patients (43.4%) had persistent disease; and eight patients (15.1%) had recurrent disease. Four patients (7.6%) died from medullary thyroid carcinoma with clinical and/or imaging evidence of neoplasia. The following aspects demonstrated statistically significant correlations with the final medical condition: positive initial cervical examination (p = 0.002); neoplastic extensions to the thyroid capsule (p = 0.004) and adjacent tissues (p = 0.034); cervical lymph node metastases (p < 0.001); diameter of neoplasia (p = 0.018); TNM (tumor, node and metastasis) Stage (p = 0.001) and evidence of distant and/or cervical diseases in the absence of a cure (p = 0.011). Through logistic regression, the presence of cervical lymph node metastases was considered an independent variable (p < 0.001).

CONCLUSIONS

Clinical and pathological aspects of patients with surgically treated medullary thyroid carcinomas are predictors of disease progression. Specifically, even treated cervical lymph node metastases are significantly correlated with disease progression.

Thyroid surgery in the tropics

In the tropics thyroid surgery is carried out either by general surgeons or ear, nose and throat surgeons and there are few places with a subspecialist endocrine or head and neck surgeon. The aim of this review is to determine the pattern of thyroid pathology, surgery and surgical outcomes in the tropics. A review of thyroid surgery in tropical regions was carried out based on published articles in English in Medline (1965-2004). The findings are also discussed in the light of the authors' own experience of thyroid disease and thyroid surgery in four continents. The pattern of thyroid pathology varies in the tropics, particularly in regions where endemic goitre is common. Endemic goitre usually regresses with iodine therapy. There is a rising incidence of thyroid autoimmune disease, particularly Graves' disease and Hashimoto's thyroiditis, probably related to an environmental immunological stimulus associated with development. Surgery is indicated for the same reasons as in the developed countries: thyrotoxicosis (more often in the absence of radioactive iodine therapy), solitary thyroid nodule and multinodular or malignant goitre. However, a preoperative cytological diagnosis will only be available in important centres where there is a pathologist. Malignancy appears more prevalent in nodules and goitres in the tropics than in the developed countries, perhaps because patients with malignancy are more likely to be referred to a surgeon. Nonetheless, the evidence suggests that thyroid surgery can be carried out safely with a minimum of complications even in remote mission hospitals with limited facilities for investigation. Standards can be set in terms of surgical outcomes; for example, mortality (0%), permanent recurrent laryngeal nerve (RLN) injury (<2%), re-exploration for haematoma(<2%), permanent hypocalcaemia (<5%) and wound infection (2.5%). The choice of operation depends on the local pathology and the likelihood of being able to obtain lifelong thyroxine. Total thyroidectomy should be avoided whenever possible if thyroxine supplies are unreliable. Advanced thyroid cancer presents a therapeutic challenge and some cases will be unresectable. The management options are limited by the resources available. Similar surgical outcomes should be able to be achieved no matter where the surgery is carried out.

Screening for thyroid disorders in asymptomatic adults from Brazilian populations

Advances in thyroid disorder diagnosis have created new thyroid disorder categories such as subclinical hyperthyroidism and subclinical hypothyroidism. In the 1980s, immunometric assaying for thyroid stimulating hormone (TSH) emerged and became defined as the most cost-effective test in thyroid disorder screening. The second step in the screening of thyroid disorders is to determine free thyroxine (FT4), and cost-effective methods for its detection are now available. Using TSH and FT4, it is possible to determine four situations: clinical hyperthyroidism, clinical hypothyroidism, subclinical hyperthyroidism and subclinical hypothyroidism. Subclinical hypothyroidism can be a strong indicator of risk for atherosclerosis and myocardial infarction in elderly women. Cardiovascular mortality among Brazilian women is one of the highest in the Western world. The best-known risk factors for cardiovascular diseases are high blood pressure, smoking, diabetes, and hypercholesterolemia. Although these are recognized as primary risk factors, there are other risk factors that could be identified as primordial risk factors. This may be the case for subclinical hypothyroidism. Early detection of thyroid disorders in women over fifty could be a highly cost-effective option in the prevention of cardiovascular disorders among Brazilian women.