[Pathological characteristics of thyroid microcarcinoma. A review of 402 biopsies]

Innovative analysis of distant metastasis in differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common thyroid cancer with a relatively high survival rate. The association between certain risk factors of distant metastasis (DM) remains uncertain. In order to assess the prognosis of patients with DTC better, the present study aimed to investigate the synergistic effects between histologic subtype, tumor size, lymph node metastasis (LNM) status and extrathyroidal extension (ETE) on the incidence of DM in DTC. Data of 96,788 patients with DTC were obtained from the Surveillance, Epidemiology and End Results database. The association between clinicopathological factors and DM was evaluated by univariate and multivariate analyses. The synergistic effects of relevant factors were determined by measuring the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (SI). The results demonstrated that tumor size, LNM status, histologic subtype and ETE were independent risk factors for DM [odds ratio (OR)=2.433; P<0.001; OR=3.998; P<0.001; OR=6.266; P<0.001; and OR=3.873; P<0.001, respectively]. In addition, a significant additive synergistic effect on DM was identified between ETE and histologic subtype, ETE and LNM status, as well as between ETE and tumor size (RERI=34.097; AP=0.706; SI=3.585; RERI=6.425; AP=0.410; SI=1.781; and RERI=76.973; AP=0.864; SI=7.930, respectively). Therefore, the results of this study revealed that ETE with follicular thyroid histology, N1 stage or large tumor size may have a synergistic effect on the risk of DM in patients with DTC. These results suggested that individualized treatment may benefit patients with DTC, and when ETE coexists with one of the identified risk factors, radical treatments may be required.

[Papillary thyroid carcinoma in a child with congenital dyshormonogenetic hypothyroidism. Case report]

INTRODUCTION

Papillary thyroid carcinoma (PTC) is a rare childhood disease. The development of PTC in dyshormonogenetic congenital hypothyroidism (CH) is infrequent, with very few case reports in literature.

OBJECTIVE

To report a case of PTC in a boy with dyshormonogenetic CH without goitre and exposed to ionising radiation. To evaluate relationships between these factors and development of PTC.

CASE REPORT

We present a boy with dyshormonogenetic CH since birth. Early hormonal substitution was initiated, with subsequent normal levels of thyrotropin and thyroid hormones. He has also congenital cardiomyopathy, exposed to interventional treatment with 10 heart catheterisations, and approximately 26 chest X-rays at paediatric doses. A thyroid nodule was found in thyroid echography at the age of 6 years old. Fine needle aspiration biopsy confirmed high probability of thyroid carcinoma (Bethesda 5). The pre-surgical thorax and cerebral scan showed no evidence of metastasis. The patient underwent total thyroidectomy. Pathological examination revealed a 0.5cm papillary thyroid micro-carcinoma in the right lobe, with no evidence of dissemination.

CONCLUSION

Genetic mutations and radiation exposure may play an important role in the development of PTC. There may be common pathways between dyshormonogenetic CH and thyroid carcinoma that need further investigation.

Unusual presentation of papillary microcarcinoma of thyroid as thigh mass

An elderly otherwise healthy male presented with a mass in thigh. Fine needle aspiration cytology (FNAC) revealed features of papillary carcinoma of thyroid, suggesting secondary deposits. Later the patient was clinically evaluated. There was no obvious thyromegaly both clinically and sonologically. The patient was followed up. One month after initial presentation, he came with an enlarged cervical lymph node and a tiny nodule in thyroid. FNAC from both the thyroid and cervical lymph node showed identical features of papillary carcinoma.