Both gender and concurrent chronic lymphocytic thyroiditis may influence the nuclear texture of papillary thyroid carcinomas cells.

A disparity in gender incidence has been reported in both papillary thyroid carcinoma (PTC) and chronic lymphocytic thyroiditis (CLT) diseases frequently associated and whose incidence has been increasing in parallel. We aimed to analyze differences in morphometric variables between male and female PTC patients and their relationship with the presence of concurrent CLT. The nuclear texture features of 100 hematoxylin-eosin stained nuclei from 100 consecutive classic PTC patients enrolled in our service were compared with their clinical and pathological features, including the presence of CLT. All patients were submitted to a standard management protocol and followed-up for 13-248 months (Mo = 117 months). Chromatin in women tended to present a denser and more homogeneous structure, in a less mottled pattern, with higher values of energy (p = 0.008) and diagonal moment (p = 0.032) than men. Concurrent CLT was more prevalent in women (41.42%) than in men (13.33%, p = 0.04) and was associated with higher cluster prominence values (p = 0.027), a parameter that indicates a predominance of high nuclear contrasted heterochromatin. A multivariate logistic regression analysis showed that higher cluster prominence was independently correlated with chromatin in patients who presented CLT but did not demonstrate any association between concurrent CLT and gender. We were unable to demonstrate any association between gender and any characteristic of tumor aggressiveness or patients outcome. Our results suggest that chromatin texture of hematoxylin-eosin stained nuclei in paraffin sections of PTC cells is related to both gender and concurrent CLT.

Absence of peritumoral fibrosis or inflammatory infiltrate may be related to clinical progression of papillary thyroid microcarcinoma.

Rio Grande do Norte (RN) shows the highest relative incidence of papillary carcinomas in Brazil. To analyze histological features that might be associated with this incidence, the authors compared thyroid glands from 463 autopsies performed in RN with 427 surgical and autopsy glands previously studied in Sao Paulo (SP). The authors found 41 papillary thyroid microcarcinomas (PTMs) in 35 glands (8.1%), an incidence similar to the one reported in SP (7.8%). However, PTMs were predominantly nonencapsulated nonsclerosing at microscopy (44.0%), in contrast with SP where these types of lesion represented only 4 out of 32 PTMs (12.5%; P = .0046). The authors suggest that these nonencapsulated lesions with no sign of inflammation may represent an early stage that may evolve to clinical cancers, contributing to the high incidence of clinically differentiated thyroid carcinomas observed in RN.

Prevalence of papillary microcarcinoma of the thyroid in Brazilian autopsy and surgical series.

In order to search for parameters to differentiate patients at low and high risk for development of thyroid cancer, we studied thyroids from 166 consecutive autopsies and 261 thyroids that were surgically resected for thyroid diseases in general. We found 32 papillary microcarcinomas, corresponding to 7.8% of autopsies and 7.2% of surgical material, with a higher incidence between 30 and 49 yr of age. Both genders were similarly affected: 9.3% of the men and 8.8% of the women in autopsy series, and 6.2% of the men and 7.3% of the women in surgical series, suggesting that hormonal factors may favor the subsequent development of clinical lesions in women. Although associated nodular goiter has been observed in 54% of autopsies and 26% of surgical specimens, while Hashimoto's thyroiditis only in surgical material (15% of the cases), we were not able to correlate risk of malignancy with any concomitant lesion. The smallest papillary microcarcinomas presented most frequently as nonencapsulated nonsclerosing tumors without inflammatory infiltrate or fibrosis, suggesting that they may represent the early stages of development. Our data show a relatively high and similar frequency of papillary microcarcinomas in surgical and autopsy series, but do not demonstrate risk factors for clinical evolution.