Endocrine Abstracts

Papillary microcarcinoma (PMC) of thyroid is being increasingly detected following thyroid surgery for various reasons. The management of incidental PMC, not clinically or radiologically evident, is not well defined often leading to over treatment. Identifying risk factors for recurrence could help in administering appropriate management.

Aims and methods: To review the incidence of PMC and management locally. Retrospective review of case notes of patients diagnosed with papillary carcinoma over 9 years (2006–2014).

Results: n=113, of which 30 were PMC (26.5%). Female=23. Mean age: 49 years. Lump in the neck was the commonest initial presentation. Patients had one FNAC on an average (Thy3 to Thy5 n=11). Nine patients with suspicious or diagnostic cytology or non-thyroidal surgeries were excluded. 21 patients had incidental PMC (total thyroidectomy n=7, lobectomy n=14). Five patients underwent completion thyroidectomy and further foci of PMC were found in three of them. Eight out of 21 patients were found to have risk factors such as size (6–10 mm), multifocality, and extrathyroidal spread. Five of eight patients had initial total thyroidectomy. Three underwent hemithyroidectomy followed by completion thyroidectomy. Completion thyroidectomy was done in one patient (MEN1) without risk factors for incidental PMC in thyroid tissue attached to parathyroid specimen. Five of 21 patients received radioiodine ablation following surgery (n=4 with risk factors, n=1 oncocytic neoplasm). 19 patients received post-operative hormonal therapy including eight with risk factors. TSH level was aimed at 0.1–0.4 mU/l. Complete suppression of TSH was noted at various stages during follow up in four of these 19 patients (21%).

Conclusion: Incidence of PMC in this cohort is in keeping with published literature. Identifying risk factors for local or regional recurrence is helpful in optimising management of incidental PMC. This could avoid unnecessary overtreatment with extensive surgery or RAI ablation or TSH suppression.