Myasthenia gravis (MG) is an autoantibody-mediated disorder affecting the neuromuscular junction causing characteristic fatigable muscle weakness. Though it can be associated with tumours of the thymus as well as thyroid disorders, it is rare for both to coexist. The exact prevalence of thyroid carcinoma in MG with thymoma is not known but only about a dozen cases have been reported in the literature. We report a case of a 38-year-old Myanmar lady who presented with weakness and breathlessness due to MG with neck swelling. On examination, she had fatigable proximal muscle weakness and thyroid enlargement with no obvious features of hyperthyroidism. Mediastinal widening and an enlarged thyroid gland were noted on her chest X-ray and chest CT. A subtotal thyroidectomy and thymectomy were done. The histology showed follicular carcinoma of the thyroid and benign thymoma. The majority of the reported cases of thyroid carcinoma in association with MG were papillary carcinoma. Follicular carcinoma thyroid associated with MG has not yet been reported in the literature.
Lymph node metastasis (LNM) in papillary thyroid cancer (PTC) has been shown to be associated with increased risk of locoregional recurrence, poor prognosis and decreased survival, especially in older patients. Hence, there is a need for a reliable biomarker for the prediction of LNM in this cancer. MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene translation or degradation and play key roles in numerous cellular functions including cell-cycle regulation, differentiation, apoptosis, invasion and migration. Various studies have demonstrated deregulation of miRNA levels in many diseases including cancers. While a large number of miRNAs have been identified from PTCs using various means, association of miRNAs with LNM in such cases is still controversial. Furthermore, studies linking most of the identified miRNAs to the mechanism of LNM have not been well documented. The aim of this review is to update readers on the current knowledge of miRNAs in relation to LNM in PTC.