Papillary Microcarcinoma of Thyroid- A Clinicopathological Study in a Tertiary Care Hospital in South India

The incidence of papillary carcinoma of thyroid has shown an increase in the last few decades. One contributing factor is the identification of Papillary Microcarcinoma of thyroid. Papillary Microcarcinoma is defined as a papillary carcinoma which is ≤ 10 mm in size in the greatest dimension. Though it is associated with excellent prognosis, controversies still exist regarding the treatment and follow up of these patients.METHODSThis study is a retrospective study done in a tertiary care hospital in South India over a period of one year from July 2016 to June 2017. All surgically removed thyroid specimens submitted to the Pathology Department of the hospital were studied. The demographic details, clinical features, ultrasound and other imaging studies were obtained from the medical records. The FNAC findings, gross features of surgically removed thyroid and histopathological findings of these thyroid specimens were recorded and analysed. The records of the follow up of these patients were obtained from the corresponding clinical department.RESULTSAmong the 486 thyroid samples received, 59 (12.13%) were malignant tumours of the thyroid, out of which Papillary carcinoma was seen in 50 cases (84.7%) including 11 cases of Papillary Microcarcinoma constituting 18.6% of all thyroid malignancies and 2.26% of thyroidectomies during the study period. Mean age of patients with PMC was 43.9 with a female: male ratio of 10:1. 10 cases were incidental PMC, while one was suspected to be papillary carcinoma on ultrasound examination and FNAC. Only one patient showed high risk features of multifocality, extrathyroidal extension and lymph node metastases. Hence she was given RAI. All patients were followed up. No recurrence has been noted in the two year period of follow up.CONCLUSIONSPapillary Microcarcinoma is being increasingly diagnosed, most of them being incidental. Hence thorough histopathological examination is mandatory to identify these lesions. Though PMC has an excellent prognosis, aggressive treatment may be required in patients with high risk features including nonincidental, lymph node metastasis, multifocality, and extra-thyroid extension.